列表控件 | 领风沐雨

Android RecyclerView 使用完全解析体验艺术般的控件

概述 RecyclerView出现已经有一段时间了，相信大家肯定不陌生了，大家可以通过导入support-v7对其进行使用。据官方的介绍，该控件用于在有限的窗口中展示大量数据集，其实这样功能的控件我们并不陌生，例如：ListView、GridView。那么有了ListView、GridView为什么还需要RecyclerView这样的控件呢？整体上看RecyclerView架构，提供了一种插拔式的体验，高度的解耦，异常的灵活，通过设置它提供的不同LayoutManager，ItemDecoration , ItemAnimator实现令人瞠目的效果。你想要控制其显示的方式，请通过布局管理器LayoutManager 你想要控制Item间的间隔（可绘制），请通过ItemDecoration 你想要控制Item增删的动画，请通过ItemAnimator 你想要控制点击、长按事件，请自己写（擦，这点尼玛。）基本使用鉴于我们对于ListView的使用特别的熟悉，对比下RecyclerView的使用代码： `mRecyclerView = findView(R.id.id_recyclerview); //设置布局管理器 mRecyclerView.setLayoutManager(layout); //设置adapter mRecyclerView.setAdapter(adapter) //设置Item增加、移除动画 mRecyclerView.setItemAnimator(new DefaultItemAnimator()); //添加分割线 mRecyclerView.addItemDecoration(new DividerItemDecoration( getActivity(), DividerItemDecoration.HORIZONTAL_LIST));` ok，相比较于ListView的代码，ListView可能只需要去设置一个adapter就能正常使用了。而RecyclerView基本需要上面一系列的步骤，那么为什么会添加这么多的步骤呢？那么就必须解释下RecyclerView的这个名字了，从它类名上看，RecyclerView代表的意义是，我只管Recycler View，也就是说RecyclerView只管回收与复用View，其他的你可以自己去设置。可以看出其高度的解耦，给予你充分的定制自由（所以你才可以轻松的通过这个控件实现ListView,GirdView，瀑布流等效果）。 Just like ListView Activity `package com.zhy.sample.demo_recyclerview; import java.util.ArrayList; import java.util.List; import android.os.Bundle; import android.support.v7.app.ActionBarActivity; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.support.v7.widget.RecyclerView.ViewHolder; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.TextView; public class HomeActivity extends ActionBarActivity { private RecyclerView mRecyclerView; private List<String> mDatas; private HomeAdapter mAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_single_recyclerview); initData(); mRecyclerView = (RecyclerView) findViewById(R.id.id_recyclerview); mRecyclerView.setLayoutManager(new LinearLayoutManager(this)); mRecyclerView.setAdapter(mAdapter = new HomeAdapter()); } protected void initData() { mDatas = new ArrayList<String>(); for (int i = 'A'; i < 'z'; i++) { mDatas.add("" + (char) i); } } class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> { @Override public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { MyViewHolder holder = new MyViewHolder(LayoutInflater.from( HomeActivity.this).inflate(R.layout.item_home, parent, false)); return holder; } @Override public void onBindViewHolder(MyViewHolder holder, int position) { holder.tv.setText(mDatas.get(position)); } @Override public int getItemCount() { return mDatas.size(); } class MyViewHolder extends ViewHolder { TextView tv; public MyViewHolder(View view) { super(view); tv = (TextView) view.findViewById(R.id.id_num); } } } }` Activity的布局文件 `<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" > <android.support.v7.widget.RecyclerView android:id="@+id/id_recyclerview" android:divider="#ffff0000" android:dividerHeight="10dp" android:layout_width="match_parent" android:layout_height="match_parent" /> </RelativeLayout>` Item的布局文件 `<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:background="#44ff0000" android:layout_height="wrap_content" > <TextView android:id="@+id/id_num" android:layout_width="match_parent" android:layout_height="50dp" android:gravity="center" android:text="1" /> </FrameLayout>` 这么看起来用法与ListView的代码基本一致哈~~ 看下效果图： ...

ScrollView下，ListView生存之道

首先讲一下我遇到的需求吧，页面是这样的，上边有东西，中间是列表，下边还有东西。首先我看到列表立刻就想到了用ListView，但是页面有限，只能用ScrollView包一下。想到就做呗。我就在ScrollView里面加了一个ListView, ListView设置的是wapcontent，这样就出现了ListView数据只显示出了一行。好的，解决问题的方案就来了。一．设置scrollView中的ListView内容全部显示，不能滑动，将滑动交给scrollView去做。做法：在设置adapter之前，重新计算ListView的高度，我这里写了一个方法： java代码 [![](http://www.eyeandroid.com/source/plugin/milu_hightLight/help.png)](http://www.eyeandroid.com/) - /** - * 动态设置listView的高度 - * count 总条目 - */ - private void setListViewHeight(ListView listView, BaseAdapter adapter, - int count) { - int totalHeight = ; - for (int i = ; i < count; i++) { - View listItem = adapter.getView(i, null, listView); - listItem.measure(, ); - totalHeight += listItem.getMeasuredHeight(); - } - - ViewGroup.LayoutParams params = listView.getLayoutParams(); - params.height = totalHeight + (listView.getDividerHeight() * count); - listView.setLayoutParams(params); - } 这样做的前提条件是布局文件中ListView的高度要指定，这样才能重新计算，不要设成wapcontent！ ...

Android RecyclerView 使用完全解析体验艺术般的控件

概述 RecyclerView出现已经有一段时间了，相信大家肯定不陌生了，大家可以通过导入support-v7对其进行使用。据官方的介绍，该控件用于在有限的窗口中展示大量数据集，其实这样功能的控件我们并不陌生，例如：ListView、GridView。那么有了ListView、GridView为什么还需要RecyclerView这样的控件呢？整体上看RecyclerView架构，提供了一种插拔式的体验，高度的解耦，异常的灵活，通过设置它提供的不同LayoutManager，ItemDecoration , ItemAnimator实现令人瞠目的效果。你想要控制其显示的方式，请通过布局管理器LayoutManager 你想要控制Item间的间隔（可绘制），请通过ItemDecoration 你想要控制Item增删的动画，请通过ItemAnimator 你想要控制点击、长按事件，请自己写（擦，这点尼玛。）基本使用鉴于我们对于ListView的使用特别的熟悉，对比下RecyclerView的使用代码： `mRecyclerView = findView(R.id.id_recyclerview); //设置布局管理器 mRecyclerView.setLayoutManager(layout); //设置adapter mRecyclerView.setAdapter(adapter) //设置Item增加、移除动画 mRecyclerView.setItemAnimator(new DefaultItemAnimator()); //添加分割线 mRecyclerView.addItemDecoration(new DividerItemDecoration( getActivity(), DividerItemDecoration.HORIZONTAL_LIST));` ok，相比较于ListView的代码，ListView可能只需要去设置一个adapter就能正常使用了。而RecyclerView基本需要上面一系列的步骤，那么为什么会添加这么多的步骤呢？那么就必须解释下RecyclerView的这个名字了，从它类名上看，RecyclerView代表的意义是，我只管Recycler View，也就是说RecyclerView只管回收与复用View，其他的你可以自己去设置。可以看出其高度的解耦，给予你充分的定制自由（所以你才可以轻松的通过这个控件实现ListView,GirdView，瀑布流等效果）。 Just like ListView Activity `package com.zhy.sample.demo_recyclerview; import java.util.ArrayList; import java.util.List; import android.os.Bundle; import android.support.v7.app.ActionBarActivity; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.support.v7.widget.RecyclerView.ViewHolder; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.TextView; public class HomeActivity extends ActionBarActivity { private RecyclerView mRecyclerView; private List<String> mDatas; private HomeAdapter mAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_single_recyclerview); initData(); mRecyclerView = (RecyclerView) findViewById(R.id.id_recyclerview); mRecyclerView.setLayoutManager(new LinearLayoutManager(this)); mRecyclerView.setAdapter(mAdapter = new HomeAdapter()); } protected void initData() { mDatas = new ArrayList<String>(); for (int i = 'A'; i < 'z'; i++) { mDatas.add("" + (char) i); } } class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.MyViewHolder> { @Override public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { MyViewHolder holder = new MyViewHolder(LayoutInflater.from( HomeActivity.this).inflate(R.layout.item_home, parent, false)); return holder; } @Override public void onBindViewHolder(MyViewHolder holder, int position) { holder.tv.setText(mDatas.get(position)); } @Override public int getItemCount() { return mDatas.size(); } class MyViewHolder extends ViewHolder { TextView tv; public MyViewHolder(View view) { super(view); tv = (TextView) view.findViewById(R.id.id_num); } } } }` Activity的布局文件 `<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" > <android.support.v7.widget.RecyclerView android:id="@+id/id_recyclerview" android:divider="#ffff0000" android:dividerHeight="10dp" android:layout_width="match_parent" android:layout_height="match_parent" /> </RelativeLayout>` Item的布局文件 `<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:background="#44ff0000" android:layout_height="wrap_content" > <TextView android:id="@+id/id_num" android:layout_width="match_parent" android:layout_height="50dp" android:gravity="center" android:text="1" /> </FrameLayout>` 这么看起来用法与ListView的代码基本一致哈~~ 看下效果图： ...

Android — RecyclerView

“A flexible view for providing a limited window into a large data set.” 可以说是ListView的升级版，ListVie中我们需要自己写ViewHolder，当然你也可以不写，是在RecylerView中，是要让写的哟~RecyclerView适用于无法在一个屏幕范围内展现格式一样的数据时，需要用多行或多列来展示。例如展示联系人，图片，视频等。用户需要滑动屏幕来查看数据，这时RecyclerView的特性就有用武之地了。比如，当用户滑动使当前一个可视的Item滑出屏幕，这个Item的视图将会被回收并在一个新Item进入可视范围后重新被使用。可回收利用View是个很实用的功能，它不仅可以减少CPU不断inflate View的开销，而且可以节省缓存View的内存开销。 RecylerView还有一大特色，就是动画！ RecyclerView不再负责显示工作和ListView不一样的是，RecyclerView不再负责Item的摆放等显示方面的功能。所有和布局、绘制等方面的工作都其拆分成不同的类进行管理。所以开发者可以自定义各种各样满足定制需求的的功能类。 RecyclerView.Adapter <td valign="top" width="454"> 托管数据集合，为每个Item创建视图 </td> </tr> <tr> <td valign="top" width="326"> RecyclerView.ViewHolder </td> <td valign="top" width="454"> 承载Item视图的子视图 </td> </tr> <tr> <td valign="top" width="326"> RecyclerView.LayoutManager </td> <td valign="top" width="454"> 负责Item视图的布局 </td> </tr> <tr> <td valign="top" width="326"> RecyclerView.ItemDecoration </td> <td valign="top" width="454"> 为每个Item视图添加子视图，在Demo中被用来绘制Divider </td> </tr> <tr> <td valign="top" width="326"> RecyclerView.ItemAnimator </td> <td valign="top" width="454"> 负责添加、删除数据时的动画效果 </td> </tr> ViewHolder 关于ViewHolder，Google早就推荐开发者使用，但也只是建议。但是现在，RecyclerView.Adapter最终要求开发者必须使用ViewHolder。 ...

Android 使用NineOldAndroids实现绚丽的ListView左右滑动删除Item效果

转载（http://blog.csdn.net/xiaanming/article/details/18311877）今天还是给大家带来自定义控件的编写，自定义一个ListView的左右滑动删除Item的效果，这个效果之前已经实现过了，有兴趣的可以看下Android 使用Scroller实现绚丽的ListView左右滑动删除Item效果，之前使用的是滑动类Scroller来实现的，但是看了下通知栏的左右滑动删除效果，确实很棒，当我们滑动Item超过一半的时候，item的透明度就变成了0，我们就知道抬起手指的时候item就被删除了，当item的透明度不为0的时候，我们抬起手指Item会回到起始位置，这样我们就知道拖动到什么位置item会删除，什么位置Item不删除，用户体验更好了，还有一个效果，就是我们滑动删除了item的时候，ListView的其他item会出现向上或者向下滚动的效果，感觉效果很棒，所以在GitHub上面搜索了下，发现很多开源库都有这个效果，比如ListViewAnimations, android-swipelistview等等，我看了下实现原理，使用的是Jake Wharton的动画开源库NineOldAndroids，这个库究竟是干嘛的呢？在API3.0（Honeycomb）, SDK新增了一个android.animation包，里面的类是实现动画效果相关的类，通过Honeycomb API，能够实现非常复杂的动画效果，但是如果开发者想在3.0以下使用这一套API, 则需要使用开源框架Nine Old Androids，在这个库中会根据我们运行的机器判断其SDK版本，如果是API3.0以上则使用Android自带的动画类，否则就使用Nine Old Androids库中，这是一个兼容库，接下来我们就来看看这个效果的具体实现吧实现该效果的主要思路先根据手指触摸的点来获取点击的是ListView的哪一个Item 当手指在屏幕上面滑动的时候，我们要使得Item跟随手指的滑动而滑动当我们抬起手指的时候，我们根据滑动的距离或者手指在屏幕上面的速度来判断Item是滑出屏幕还是滑动至其实位置 Item滑出屏幕时，使ListView的其他item产生向上挤压或者向下挤压的效果大致的思路这是这四步，其中的一些细节接下来我会一一为大家解答的，接下来我们就用代码来实现这种效果吧首先我们新建一个工程，叫Swipedismisslistview,我们需要将Nine Old Androids这个库引入到工程，大家可以去https://github.com/JakeWharton/NineOldAndroids下载,可以使用Jar包，也可以使用工程库的形式引入到我们自己的工程，我们还需要自定义一个ListView，我们先看代码然后给大家讲解下具体的功能实现 **[java]** [view plain](http://blog.csdn.net/xiaanming/article/details/18311877#)[copy](http://blog.csdn.net/xiaanming/article/details/18311877#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/159353)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/159353/fork) <div> <embed id="ZeroClipboardMovie_1" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_1"> </embed> </div> </div> - package com.example.swipedismisslistview; - - import static com.nineoldandroids.view.ViewHelper.setAlpha; - import static com.nineoldandroids.view.ViewHelper.setTranslationX; - import android.content.Context; - import android.util.AttributeSet; - import android.view.MotionEvent; - import android.view.VelocityTracker; - import android.view.View; - import android.view.ViewConfiguration; - import android.view.ViewGroup; - import android.widget.AdapterView; - import android.widget.ListView; - - import com.nineoldandroids.animation.Animator; - import com.nineoldandroids.animation.AnimatorListenerAdapter; - import com.nineoldandroids.animation.ValueAnimator; - import com.nineoldandroids.view.ViewHelper; - import com.nineoldandroids.view.ViewPropertyAnimator; - /** - * @blog http://blog.csdn.net/xiaanming - * - * @author xiaanming - * - */ - public class SwipeDismissListView extends ListView { - /** - * 认为是用户滑动的最小距离 - */ - private int mSlop; - /** - * 滑动的最小速度 - */ - private int mMinFlingVelocity; - /** - * 滑动的最大速度 - */ - private int mMaxFlingVelocity; - /** - * 执行动画的时间 - */ - protected long mAnimationTime = 150; - /** - * 用来标记用户是否正在滑动中 - */ - private boolean mSwiping; - /** - * 滑动速度检测类 - */ - private VelocityTracker mVelocityTracker; - /** - * 手指按下的position - */ - private int mDownPosition; - /** - * 按下的item对应的View - */ - private View mDownView; - private float mDownX; - private float mDownY; - /** - * item的宽度 - */ - private int mViewWidth; - /** - * 当ListView的Item滑出界面回调的接口 - */ - private OnDismissCallback onDismissCallback; - - /** - * 设置动画时间 - * - * @param mAnimationTime - */ - public void setmAnimationTime(long mAnimationTime) { - this.mAnimationTime = mAnimationTime; - } - - /** - * 设置删除回调接口 - * - * @param onDismissCallback - */ - public void setOnDismissCallback(OnDismissCallback onDismissCallback) { - this.onDismissCallback = onDismissCallback; - } - - public SwipeDismissListView(Context context) { - this(context, null); - } - - public SwipeDismissListView(Context context, AttributeSet attrs) { - this(context, attrs, ); - } - - public SwipeDismissListView(Context context, AttributeSet attrs, - int defStyle) { - super(context, attrs, defStyle); - - ViewConfiguration vc = ViewConfiguration.get(context); - mSlop = vc.getScaledTouchSlop(); - mMinFlingVelocity = vc.getScaledMinimumFlingVelocity() * 8; //获取滑动的最小速度 - mMaxFlingVelocity = vc.getScaledMaximumFlingVelocity(); //获取滑动的最大速度 - } - - - @Override - public boolean onTouchEvent(MotionEvent ev) { - switch (ev.getAction()) { - case MotionEvent.ACTION_DOWN: - handleActionDown(ev); - break; - case MotionEvent.ACTION_MOVE: - return handleActionMove(ev); - case MotionEvent.ACTION_UP: - handleActionUp(ev); - break; - } - return super.onTouchEvent(ev); - } - - /** - * 按下事件处理 - * - * @param ev - * @return - */ - private void handleActionDown(MotionEvent ev) { - mDownX = ev.getX(); - mDownY = ev.getY(); - - mDownPosition = pointToPosition((int) mDownX, (int) mDownY); - - if (mDownPosition == AdapterView.INVALID_POSITION) { - return; - } - - mDownView = getChildAt(mDownPosition – getFirstVisiblePosition()); - - if (mDownView != null) { - mViewWidth = mDownView.getWidth(); - } - - //加入速度检测 - mVelocityTracker = VelocityTracker.obtain(); - mVelocityTracker.addMovement(ev); - } - - - /** - * 处理手指滑动的方法 - * - * @param ev - * @return - */ - private boolean handleActionMove(MotionEvent ev) { - if (mVelocityTracker == null || mDownView == null) { - return super.onTouchEvent(ev); - } - - // 获取X方向滑动的距离 - float deltaX = ev.getX() – mDownX; - float deltaY = ev.getY() – mDownY; - - // X方向滑动的距离大于mSlop并且Y方向滑动的距离小于mSlop，表示可以滑动 - if (Math.abs(deltaX) > mSlop && Math.abs(deltaY) < mSlop) { - mSwiping = true; - - //当手指滑动item,取消item的点击事件，不然我们滑动Item也伴随着item点击事件的发生 - MotionEvent cancelEvent = MotionEvent.obtain(ev); - cancelEvent.setAction(MotionEvent.ACTION_CANCEL | - (ev.getActionIndex()<< MotionEvent.ACTION_POINTER_INDEX_SHIFT)); - onTouchEvent(cancelEvent); - } - - if (mSwiping) { - // 跟谁手指移动item - ViewHelper.setTranslationX(mDownView, deltaX); - // 透明度渐变 - ViewHelper.setAlpha(mDownView, Math.max(0f, Math.min(1f, 1f – 2f * Math.abs(deltaX)/ mViewWidth))); - - // 手指滑动的时候,返回true，表示SwipeDismissListView自己处理onTouchEvent,其他的就交给父类来处理 - return true; - } - - return super.onTouchEvent(ev); - - } - - /** - * 手指抬起的事件处理 - * @param ev - */ - private void handleActionUp(MotionEvent ev) { - if (mVelocityTracker == null || mDownView == null|| !mSwiping) { - return; - } - - float deltaX = ev.getX() – mDownX; - - //通过滑动的距离计算出X,Y方向的速度 - mVelocityTracker.computeCurrentVelocity(1000); - float velocityX = Math.abs(mVelocityTracker.getXVelocity()); - float velocityY = Math.abs(mVelocityTracker.getYVelocity()); - - boolean dismiss = false; //item是否要滑出屏幕 - boolean dismissRight = false;//是否往右边删除 - - //当拖动item的距离大于item的一半，item滑出屏幕 - if (Math.abs(deltaX) > mViewWidth / 2) { - dismiss = true; - dismissRight = deltaX > ; - - //手指在屏幕滑动的速度在某个范围内，也使得item滑出屏幕 - } else if (mMinFlingVelocity <= velocityX - && velocityX <= mMaxFlingVelocity && velocityY < velocityX) { - dismiss = true; - dismissRight = mVelocityTracker.getXVelocity() > ; - } - - if (dismiss) { - ViewPropertyAnimator.animate(mDownView) - .translationX(dismissRight ? mViewWidth : -mViewWidth)//X轴方向的移动距离 - .alpha() - .setDuration(mAnimationTime) - .setListener(new AnimatorListenerAdapter() { - @Override - public void onAnimationEnd(Animator animation) { - //Item滑出界面之后执行删除 - performDismiss(mDownView, mDownPosition); - } - }); - } else { - //将item滑动至开始位置 - ViewPropertyAnimator.animate(mDownView) - .translationX() - .alpha(1) - .setDuration(mAnimationTime).setListener(null); - } - - //移除速度检测 - if(mVelocityTracker != null){ - mVelocityTracker.recycle(); - mVelocityTracker = null; - } - - mSwiping = false; - } - - - - /** - * 在此方法中执行item删除之后，其他的item向上或者向下滚动的动画，并且将position回调到方法onDismiss()中 - * @param dismissView - * @param dismissPosition - */ - private void performDismiss(final View dismissView, final int dismissPosition) { - final ViewGroup.LayoutParams lp = dismissView.getLayoutParams();//获取item的布局参数 - final int originalHeight = dismissView.getHeight();//item的高度 - - ValueAnimator animator = ValueAnimator.ofInt(originalHeight, ).setDuration(mAnimationTime); - animator.start(); - - animator.addListener(new AnimatorListenerAdapter() { - @Override - public void onAnimationEnd(Animator animation) { - if (onDismissCallback != null) { - onDismissCallback.onDismiss(dismissPosition); - } - - //这段代码很重要，因为我们并没有将item从ListView中移除，而是将item的高度设置为0 - //所以我们在动画执行完毕之后将item设置回来 - ViewHelper.setAlpha(dismissView, 1f); - ViewHelper.setTranslationX(dismissView, ); - ViewGroup.LayoutParams lp = dismissView.getLayoutParams(); - lp.height = originalHeight; - dismissView.setLayoutParams(lp); - - } - }); - - animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { - @Override - public void onAnimationUpdate(ValueAnimator valueAnimator) { - //这段代码的效果是ListView删除某item之后，其他的item向上滑动的效果 - lp.height = (Integer) valueAnimator.getAnimatedValue(); - dismissView.setLayoutParams(lp); - } - }); - - } - - /** - * 删除的回调接口 - * - * @author xiaanming - * - */ - public interface OnDismissCallback { - public void onDismiss(int dismissPosition); - } - - } 看过Android 使用Scroller实现绚丽的ListView左右滑动删除Item效果你会发现，这个自定义的SwipeDismissListView只重写了onTouchEvent()方法，其实我们重写这一个方法就能实现我们需要的效果 ...

github源码分享PinnedSectionListView：分组的listView滑动中固定组标题的实现

在很多应用中，看到这样的listview：listview滑动过程中分组标题固定在上方，当第二个组滑上来时，第一个组才跟着上滑，下一个组固定，直到该组也滑出上边缘。世上无难事只怕有心人，在github上就有人做出来了，而且效果很好（后来发现安卓自带应用中联系人应用就是这样的，估计github的作者也是仿照着联系人做出来的吧）。先看截图： PinnedSectionListView继承自listview，众所周知listview的每个子view都是按顺序跟着滚动的，要实现联系人listview的效果还真的找不到思路。看了PinnedSectionListView之后，感觉要改造一个现有的控件，一般都是通过重绘子view来实现的。ViewGroup（ListView继承自它）重绘子view的方法是dispatchDraw。看看PinnedSectionListView在dispatchDraw中有那些特别的处理： 1 <div class="line number2 index1 alt1"> 2 </div> <div class="line number3 index2 alt2"> 3 </div> <div class="line number4 index3 alt1"> 4 </div> <div class="line number5 index4 alt2"> 5 </div> <div class="line number6 index5 alt1"> 6 </div> <div class="line number7 index6 alt2"> 7 </div> <div class="line number8 index7 alt1"> 8 </div> <div class="line number9 index8 alt2"> 9 </div> <div class="line number10 index9 alt1"> 10 </div> <div class="line number11 index10 alt2"> 11 </div> <div class="line number12 index11 alt1"> 12 </div> <div class="line number13 index12 alt2"> 13 </div> <div class="line number14 index13 alt1"> 14 </div> <div class="line number15 index14 alt2"> 15 </div> <div class="line number16 index15 alt1"> 16 </div> <div class="line number17 index16 alt2"> 17 </div> <div class="line number18 index17 alt1"> 18 </div> <div class="line number19 index18 alt2"> 19 </div> <div class="line number20 index19 alt1"> 20 </div> <div class="line number21 index20 alt2"> 21 </div> <div class="line number22 index21 alt1"> 22 </div> <div class="line number23 index22 alt2"> 23 </div> <div class="line number24 index23 alt1"> 24 </div> <div class="line number25 index24 alt2"> 25 </div> </td> <td class="code"> <div class="container"> <div class="line number1 index0 alt2"> `@Override` </div> <div class="line number2 index1 alt1"> `protected void dispatchDraw(Canvas canvas) {` </div> <div class="line number3 index2 alt2"> ` ``super``.dispatchDraw(canvas);` </div> <div class="line number4 index3 alt1"> ` ``if` `(mPinnedSection != ``null``) {` </div> <div class="line number5 index4 alt2"> ` ``// prepare variables` </div> <div class="line number6 index5 alt1"> ` ``int pLeft = getListPaddingLeft();` </div> <div class="line number7 index6 alt2"> ` ``int pTop = getListPaddingTop();` </div> <div class="line number8 index7 alt1"> ` ``View view = mPinnedSection.view;` </div> <div class="line number9 index8 alt2"> ` ``// draw child` </div> <div class="line number10 index9 alt1"> ` ``canvas.save();` </div> <div class="line number11 index10 alt2"> ` ``int clipHeight = view.getHeight() +` </div> <div class="line number12 index11 alt1"> ` ``(mShadowDrawable == ``null` `? 0 : Math.min(mShadowHeight, mSectionsDistanceY));` </div> <div class="line number13 index12 alt2"> ` ``canvas.clipRect(pLeft, pTop, pLeft + view.getWidth(), pTop + clipHeight);` </div> <div class="line number14 index13 alt1"> ` ``canvas.translate(pLeft, pTop + mTranslateY);` </div> <div class="line number15 index14 alt2"> ` ``drawChild(canvas, mPinnedSection.view, getDrawingTime());` </div> <div class="line number16 index15 alt1"> ` ``if` `(mShadowDrawable != ``null` `&& mSectionsDistanceY > 0) {` </div> <div class="line number17 index16 alt2"> ` ``mShadowDrawable.setBounds(mPinnedSection.view.getLeft(),` </div> <div class="line number18 index17 alt1"> ` ``mPinnedSection.view.getBottom(),` </div> <div class="line number19 index18 alt2"> ` ``mPinnedSection.view.getRight(),` </div> <div class="line number20 index19 alt1"> ` ``mPinnedSection.view.getBottom() + mShadowHeight);` </div> <div class="line number21 index20 alt2"> ` ``mShadowDrawable.draw(canvas);` </div> <div class="line number22 index21 alt1"> ` ``}` </div> <div class="line number23 index22 alt2"> ` ``canvas.restore();` </div> <div class="line number24 index23 alt1"> ` ``}` </div> <div class="line number25 index24 alt2"> `}` </div> </div> </td> </tr> </table> 关键在于```canvas.translate(pLeft, pTop + mTranslateY);意思是在绘制mPinnedSection的时候，listview滑动了多长的距离，就将canvas移动多少的距离，使mPinnedSection`始终在可见的范围内固定不变。 ...

Android学习小Demo（12）TodoList实现ListView的分组实现

很多情况下，我们想要ListView上面展示的东西是可以分组的，比如联系人列表，国家列表啊，这样看起来数据的展现比较有层次感，而且也有助于我们快速定位到某一个具体的条目上，具体效果请看下图：这是前面TodoList小demo的MainActivity，主要是来展现用户添加的任务的，在原来的基础上添加了分组的效果。接下来我们具体来讲一下这个效果是怎么实现的。这是利用开源库StickyListHeaders(传送门：https://github.com/emilsjolander/StickyListHeaders）来实现的，这个实现的效果是基于ListView的，而其实也有关于GridView而实现的分组的效果，大家可以参考一下xiaanming的博客（他的文章名字都很长。。。）： Android 使用开源库StickyGridHeaders来实现带sections和headers的GridView显示本地图片效果 0）关于如何导进开源库，大家请参考：如何导进开源库StickyListHeaders 1）然后，我们要想清楚一件事情，即分组的ListView，是包含两部分：Header 和 Item，所以相对应的我们也要为其定义两个Layout，如下： 1.1）task_header.xml **[html]** [view plain](http://blog.csdn.net/linmiansheng/article/details/20747775#)[copy](http://blog.csdn.net/linmiansheng/article/details/20747775#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/224769)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/224769/fork) <div> <embed id="ZeroClipboardMovie_1" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_1"> </embed> </div> </div> - <?xml version=“1.0” encoding=“utf-8”?> - <RelativeLayout xmlns:android=“http://schemas.android.com/apk/res/android” - android:layout_width=“match_parent” - android:layout_height=“match_parent” - android:background=“@drawable/header_selector” > - - <TextView - android:id=“@+id/tvHeader” - android:layout_width=“wrap_content” - android:layout_height=“match_parent” - android:layout_gravity=“start|left” - android:padding=“5dp” - android:textColor=“@android:color/white” - android:textSize=“17sp” - android:textStyle=“bold” /> - - </RelativeLayout> 因为我们在Header上面只是展现一个日期，所以我们只需要一个TextView即可。 ...

android ListView 设置分割线 Divider

这是一个极其隐蔽的 BUG 首先需求是：用 ColorDrawable 设置 ListView 分割线 ``` listView.setDivider(new ColorDrawable(0xffd4d5d6)); ``` 这样原理上绝对说得过去，但是你怎么都看不到效果，为什么呢，看源码吧！ ![复制代码](http://common.cnblogs.com/images/copycode.gif) public void setDivider(Drawable divider) { if (divider != null) { mDividerHeight = divider.getIntrinsicHeight(); } else { mDividerHeight = 0; } //.... ![复制代码](http://common.cnblogs.com/images/copycode.gif) mDividerHeight 是分割线的高度，我们再看 [Drawable](eclipse-javadoc:%E2%98%82=MopoGameLauncher/E:%5C/adt-bundle-windows-x86_64-20130219%5C/sdk%5C/platforms%5C/android-17%5C/android.jar%3Candroid.graphics.drawable(Drawable.class%E2%98%83Drawable).getIntrinsicHeight() ``` public int getIntrinsicHeight() { return -1; } ``` 返回 -1，而 ColorDrawable 并没有重载此方法！有些人运气好，在后面加了一句 listView.setDividerHeight(2); 这样问题就解决了，但是当你把这句放前面，就不知道为什么了！所以正确方法是： ``` listView.setDivider(new ColorDrawable(0xffd4d5d6)); listView.setDividerHeight(2); ```

JqueryMobile动态生成listView并刷新的方法!

JqueryMobile动态生成listView并刷新的方法！ **[javascript]** [view plain](http://blog.csdn.net/zz_mm/article/details/6836503#)[copy](http://blog.csdn.net/zz_mm/article/details/6836503#) <div> </div> </div> - function queryEntfernungen(tx, results) - alert(“This Hello works”); - var len = results.rows.length; - // This For works fine - - for (var i = 0; i < len; i++) { - $(“div[data-role=content] ul”).append(‘- <a href=”‘+results.rows.item(i).name+‘”>’+results.rows.item(i).name+‘</a>’); - } - $(“div[data-role=content] ul”).listview(‘refresh’); // This also works 但是下面的方法却也能成功! ...

Android UI开发: 横向ListView(HorizontalListView)及一个简单相册的完整实现 (附源码下载)

本文内容： 1、横向ListView的所有实现思路; 2、其中一个最通用的思路HorizontalListView，并基于横向ListView开发一个简单的相册； 3、实现的横向ListView在点击、浏览时item背景会变色，并解决了listview里setSelected造成item的选择状态混乱的问题。众所周知，ListView默认的方向是垂直的，但有些时候人们更喜欢横向ListView。纵观整个网络，横向ListView的实现思路如下: 1、在布局里用HorizontalScrollView包含一个ListView，参考这里; 2、利用GridView，把它的行数设为1行； 3、有人继承ListView构造了一个HorizontalScrollListView，参见：这里 4、国外一位大牛继承AdapterView构造的HorizontalListView，这是以上所有方法里本人认为最正统的方法，本文即基于此方法，参见:这里下面看源码：这是Activity的布局文件:activity_main.xml **[html]** [view plain](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[copy](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[print](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[?](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/237690)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/237690/fork) <div> </div> </div> </div> - <span style=“font-family: ‘Comic Sans MS’; font-size: 18px;”><RelativeLayout xmlns:android=“http://schemas.android.com/apk/res/android” - xmlns:tools=“http://schemas.android.com/tools” - android:layout_width=“match_parent” - android:layout_height=“match_parent” - android:paddingBottom=“@dimen/activity_vertical_margin” - android:paddingLeft=“@dimen/activity_horizontal_margin” - android:paddingRight=“@dimen/activity_horizontal_margin” - android:paddingTop=“@dimen/activity_vertical_margin” - tools:context=“.MainActivity” - > - - <org.yanzi.ui.HorizontalListView - android:id=“@+id/horizon_listview” - android:layout_width=“match_parent” - android:layout_height=“150dip” - android:layout_alignParentTop=“true” - > - </org.yanzi.ui.HorizontalListView> - <ImageView - android:id=“@+id/image_preview” - android:layout_width=“wrap_content” - android:layout_height=“wrap_content” - android:layout_below=“@id/horizon_listview” - android:layout_centerInParent=“true” - android:clickable=“true” - android:background=“@drawable/selector_imageview_background” - /> - <!– android:background=”@android:drawable/ic_menu_gallery” –> - - </RelativeLayout></span> 这是横向listview的每个item的布局，图片+文字，horizontal_list_item.xml **[html]** [view plain](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[copy](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[print](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[?](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/237690)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/237690/fork) <div> </div> </div> </div> - <span style=“font-family: ‘Comic Sans MS’; font-size: 18px;”><?xml version=“1.0” encoding=“utf-8”?> - <LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android” - android:layout_width=“wrap_content” - android:layout_height=“wrap_content” - android:paddingLeft=“2dip” - android:paddingRight=“2dip” - android:paddingTop=“2dip” - android:paddingBottom=“2dip” - android:orientation=“vertical” - android:gravity=“center” - android:clickable=“true” - android:background=“@drawable/selector_item_background”> - <ImageView - android:id=“@+id/img_list_item” - android:layout_width=“wrap_content” - android:layout_height=“wrap_content”/> - <TextView - android:id=“@+id/text_list_item” - android:layout_width=“match_parent” - android:layout_height=“wrap_content” - android:gravity=“center”/> - - </LinearLayout> - </span> 下面文件是selector_imageview_background.xml，这是大图片你点击浏览时背景发生变化的selector，没有啥实际作用。 **[html]** [view plain](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[copy](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[print](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[?](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/237690)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/237690/fork) <div> </div> </div> </div> - <span style=“font-family: ‘Comic Sans MS’; font-size: 18px;”><?xml version=“1.0” encoding=“utf-8”?> - <selector xmlns:android=“http://schemas.android.com/apk/res/android”> - - <item android:drawable=“@android:color/holo_green_light” android:state_pressed=“true”/> - <item android:drawable=“@android:color/holo_green_light” android:state_focused=“true”/> - <item android:drawable=“@drawable/image_background”></item> - <!– android:drawable=”@android:color/transparent” –> - </selector></span> 下面是每个item的selector，在focus和select时颜色会发生变化:selector_item_background.xml **[html]** [view plain](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[copy](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[print](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[?](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/237690)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/237690/fork) <div> </div> </div> </div> - <span style=“font-family: ‘Comic Sans MS’; font-size: 18px;”><?xml version=“1.0” encoding=“utf-8”?> - <selector xmlns:android=“http://schemas.android.com/apk/res/android”> - - <item android:drawable=“@android:color/holo_red_light” android:state_selected=“true”/> - <item android:drawable=“@android:color/holo_green_dark” android:state_pressed=“true”/> - <item android:drawable=“@android:color/transparent”/> - - </selector></span> 主程序:MainActivity.java **[java]** [view plain](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[copy](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[print](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[?](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/237690)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/237690/fork) <div> </div> </div> </div> - “font-family: ‘Comic Sans MS’; font-size: 18px;”>package org.yanzi.testhorizontallistview; - - import org.yanzi.ui.HorizontalListView; - import org.yanzi.ui.HorizontalListViewAdapter; - - import android.app.Activity; - import android.os.Bundle; - import android.view.Menu; - import android.view.View; - import android.widget.AdapterView; - import android.widget.AdapterView.OnItemClickListener; - import android.widget.ImageView; - - public class MainActivity extends Activity { - HorizontalListView hListView; - HorizontalListViewAdapter hListViewAdapter; - ImageView previewImg; - View olderSelectView = null; - @Override - protected void onCreate(Bundle savedInstanceState) { - super.onCreate(savedInstanceState); - setContentView(R.layout.activity_main); - initUI(); - } - - @Override - public boolean onCreateOptionsMenu(Menu menu) { - // Inflate the menu; this adds items to the action bar if it is present. - getMenuInflater().inflate(R.menu.main, menu); - return true; - } - public void initUI(){ - hListView = (HorizontalListView)findViewById(R.id.horizon_listview); - previewImg = (ImageView)findViewById(R.id.image_preview); - String[] titles = {“怀师”, “南怀瑾军校”, “闭关”, “南怀瑾”, “南公庄严照”, “怀师法相”}; - final int[] ids = {R.drawable.nanhuaijin_miss, R.drawable.nanhuaijin_school, - R.drawable.nanhuaijin_biguan, R.drawable.nanhuaijin, - R.drawable.nanhuaijin_zhuangyan, R.drawable.nanhuaijin_faxiang}; - hListViewAdapter = new HorizontalListViewAdapter(getApplicationContext(),titles,ids); - hListView.setAdapter(hListViewAdapter); - // hListView.setOnItemSelectedListener(new OnItemSelectedListener() { - // - // @Override - // public void onItemSelected(AdapterView<?> parent, View view, - // int position, long id) { - // // TODO Auto-generated method stub - // if(olderSelected != null){ - // olderSelected.setSelected(false); //上一个选中的View恢复原背景 - // } - // olderSelected = view; - // view.setSelected(true); - // } - // - // @Override - // public void onNothingSelected(AdapterView<?> parent) { - // // TODO Auto-generated method stub - // - // } - // }); - hListView.setOnItemClickListener(new OnItemClickListener() { - - @Override - public void onItemClick(AdapterView<?> parent, View view, - int position, long id) { - // TODO Auto-generated method stub - // if(olderSelectView == null){ - // olderSelectView = view; - // }else{ - // olderSelectView.setSelected(false); - // olderSelectView = null; - // } - // olderSelectView = view; - // view.setSelected(true); - previewImg.setImageResource(ids[position]); - hListViewAdapter.setSelectIndex(position); - hListViewAdapter.notifyDataSetChanged(); - - } - }); - - } - - } - HorizontalListView.java 这就是自定义的横向listview **[java]** [view plain](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[copy](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[print](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[?](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/237690)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/237690/fork) <div> </div> </div> </div> - “font-family: ‘Comic Sans MS’; font-size: 18px;”>package org.yanzi.ui; - - /* - * HorizontalListView.java v1.5 - * - * - * The MIT License - * Copyright (c) 2011 Paul Soucy (paul@dev-smart.com) - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the “Software”), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - * - */ - - - import java.util.LinkedList; - import java.util.Queue; - - import android.content.Context; - import android.database.DataSetObserver; - import android.graphics.Rect; - import android.util.AttributeSet; - import android.view.GestureDetector; - import android.view.GestureDetector.OnGestureListener; - import android.view.MotionEvent; - import android.view.View; - import android.widget.AdapterView; - import android.widget.ListAdapter; - import android.widget.Scroller; - - public class HorizontalListView extends AdapterView<ListAdapter> { - - public boolean mAlwaysOverrideTouch = true; - protected ListAdapter mAdapter; - private int mLeftViewIndex = –1; - private int mRightViewIndex = ; - protected int mCurrentX; - protected int mNextX; - private int mMaxX = Integer.MAX_VALUE; - private int mDisplayOffset = ; - protected Scroller mScroller; - private GestureDetector mGesture; - private Queue<View> mRemovedViewQueue = new LinkedList<View>(); - private OnItemSelectedListener mOnItemSelected; - private OnItemClickListener mOnItemClicked; - private OnItemLongClickListener mOnItemLongClicked; - private boolean mDataChanged = false; - - - public HorizontalListView(Context context, AttributeSet attrs) { - super(context, attrs); - initView(); - } - - private synchronized void initView() { - mLeftViewIndex = –1; - mRightViewIndex = ; - mDisplayOffset = ; - mCurrentX = ; - mNextX = ; - mMaxX = Integer.MAX_VALUE; - mScroller = new Scroller(getContext()); - mGesture = new GestureDetector(getContext(), mOnGesture); - } - - @Override - public void setOnItemSelectedListener(AdapterView.OnItemSelectedListener listener) { - mOnItemSelected = listener; - } - - @Override - public void setOnItemClickListener(AdapterView.OnItemClickListener listener){ - mOnItemClicked = listener; - } - - @Override - public void setOnItemLongClickListener(AdapterView.OnItemLongClickListener listener) { - mOnItemLongClicked = listener; - } - - private DataSetObserver mDataObserver = new DataSetObserver() { - - @Override - public void onChanged() { - synchronized(HorizontalListView.this){ - mDataChanged = true; - } - invalidate(); - requestLayout(); - } - - @Override - public void onInvalidated() { - reset(); - invalidate(); - requestLayout(); - } - - }; - - @Override - public ListAdapter getAdapter() { - return mAdapter; - } - - @Override - public View getSelectedView() { - //TODO: implement - return null; - } - - @Override - public void setAdapter(ListAdapter adapter) { - if(mAdapter != null) { - mAdapter.unregisterDataSetObserver(mDataObserver); - } - mAdapter = adapter; - mAdapter.registerDataSetObserver(mDataObserver); - reset(); - } - - private synchronized void reset(){ - initView(); - removeAllViewsInLayout(); - requestLayout(); - } - - @Override - public void setSelection(int position) { - //TODO: implement - } - - private void addAndMeasureChild(final View child, int viewPos) { - LayoutParams params = child.getLayoutParams(); - if(params == null) { - params = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT); - } - - addViewInLayout(child, viewPos, params, true); - child.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST), - MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.AT_MOST)); - } - - - - @Override - protected synchronized void onLayout(boolean changed, int left, int top, int right, int bottom) { - super.onLayout(changed, left, top, right, bottom); - - if(mAdapter == null){ - return; - } - - if(mDataChanged){ - int oldCurrentX = mCurrentX; - initView(); - removeAllViewsInLayout(); - mNextX = oldCurrentX; - mDataChanged = false; - } - - if(mScroller.computeScrollOffset()){ - int scrollx = mScroller.getCurrX(); - mNextX = scrollx; - } - - if(mNextX <= ){ - mNextX = ; - mScroller.forceFinished(true); - } - if(mNextX >= mMaxX) { - mNextX = mMaxX; - mScroller.forceFinished(true); - } - - int dx = mCurrentX – mNextX; - - removeNonVisibleItems(dx); - fillList(dx); - positionItems(dx); - - mCurrentX = mNextX; - - if(!mScroller.isFinished()){ - post(new Runnable(){ - @Override - public void run() { - requestLayout(); - } - }); - - } - } - - private void fillList(final int dx) { - int edge = ; - View child = getChildAt(getChildCount()-1); - if(child != null) { - edge = child.getRight(); - } - fillListRight(edge, dx); - - edge = ; - child = getChildAt(); - if(child != null) { - edge = child.getLeft(); - } - fillListLeft(edge, dx); - - - } - - private void fillListRight(int rightEdge, final int dx) { - while(rightEdge + dx < getWidth() && mRightViewIndex < mAdapter.getCount()) { - - View child = mAdapter.getView(mRightViewIndex, mRemovedViewQueue.poll(), this); - addAndMeasureChild(child, –1); - rightEdge += child.getMeasuredWidth(); - - if(mRightViewIndex == mAdapter.getCount()-1) { - mMaxX = mCurrentX + rightEdge – getWidth(); - } - - if (mMaxX < ) { - mMaxX = ; - } - mRightViewIndex++; - } - - } - - private void fillListLeft(int leftEdge, final int dx) { - while(leftEdge + dx > && mLeftViewIndex >= ) { - View child = mAdapter.getView(mLeftViewIndex, mRemovedViewQueue.poll(), this); - addAndMeasureChild(child, ); - leftEdge -= child.getMeasuredWidth(); - mLeftViewIndex–; - mDisplayOffset -= child.getMeasuredWidth(); - } - } - - private void removeNonVisibleItems(final int dx) { - View child = getChildAt(); - while(child != null && child.getRight() + dx <= ) { - mDisplayOffset += child.getMeasuredWidth(); - mRemovedViewQueue.offer(child); - removeViewInLayout(child); - mLeftViewIndex++; - child = getChildAt(); - - } - - child = getChildAt(getChildCount()-1); - while(child != null && child.getLeft() + dx >= getWidth()) { - mRemovedViewQueue.offer(child); - removeViewInLayout(child); - mRightViewIndex–; - child = getChildAt(getChildCount()-1); - } - } - - private void positionItems(final int dx) { - if(getChildCount() > ){ - mDisplayOffset += dx; - int left = mDisplayOffset; - for(int i=;i<getChildCount();i++){ - View child = getChildAt(i); - int childWidth = child.getMeasuredWidth(); - child.layout(left, , left + childWidth, child.getMeasuredHeight()); - left += childWidth + child.getPaddingRight(); - } - } - } - - public synchronized void scrollTo(int x) { - mScroller.startScroll(mNextX, , x – mNextX, ); - requestLayout(); - } - - @Override - public boolean dispatchTouchEvent(MotionEvent ev) { - boolean handled = super.dispatchTouchEvent(ev); - handled |= mGesture.onTouchEvent(ev); - return handled; - } - - protected boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, - float velocityY) { - synchronized(HorizontalListView.this){ - mScroller.fling(mNextX, , (int)-velocityX, , , mMaxX, , ); - } - requestLayout(); - - return true; - } - - protected boolean onDown(MotionEvent e) { - mScroller.forceFinished(true); - return true; - } - - private OnGestureListener mOnGesture = new GestureDetector.SimpleOnGestureListener() { - - @Override - public boolean onDown(MotionEvent e) { - return HorizontalListView.this.onDown(e); - } - - @Override - public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, - float velocityY) { - return HorizontalListView.this.onFling(e1, e2, velocityX, velocityY); - } - - @Override - public boolean onScroll(MotionEvent e1, MotionEvent e2, - float distanceX, float distanceY) { - - synchronized(HorizontalListView.this){ - mNextX += (int)distanceX; - } - requestLayout(); - - return true; - } - - @Override - public boolean onSingleTapConfirmed(MotionEvent e) { - for(int i=;i<getChildCount();i++){ - View child = getChildAt(i); - if (isEventWithinView(e, child)) { - if(mOnItemClicked != null){ - mOnItemClicked.onItemClick(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId( mLeftViewIndex + 1 + i )); - } - if(mOnItemSelected != null){ - mOnItemSelected.onItemSelected(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId( mLeftViewIndex + 1 + i )); - } - break; - } - - } - return true; - } - - @Override - public void onLongPress(MotionEvent e) { - int childCount = getChildCount(); - for (int i = ; i < childCount; i++) { - View child = getChildAt(i); - if (isEventWithinView(e, child)) { - if (mOnItemLongClicked != null) { - mOnItemLongClicked.onItemLongClick(HorizontalListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId(mLeftViewIndex + 1 + i)); - } - break; - } - - } - } - - private boolean isEventWithinView(MotionEvent e, View child) { - Rect viewRect = new Rect(); - int[] childPosition = new int[2]; - child.getLocationOnScreen(childPosition); - int left = childPosition[]; - int right = left + child.getWidth(); - int top = childPosition[1]; - int bottom = top + child.getHeight(); - viewRect.set(left, top, right, bottom); - return viewRect.contains((int) e.getRawX(), (int) e.getRawY()); - } - }; - - - - } - HorizontalListViewAdapter.java 横向listview的适配器，我将他单独写到一个java文件里。 **[java]** [view plain](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[copy](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[print](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[?](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/237690)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/237690/fork) <div> </div> </div> </div> - “font-family: ‘Comic Sans MS’; font-size: 18px;”>package org.yanzi.ui; - - import org.yanzi.testhorizontallistview.R; - import org.yanzi.util.BitmapUtil; - - import android.content.Context; - import android.graphics.Bitmap; - import android.graphics.drawable.Drawable; - import android.media.ThumbnailUtils; - import android.view.LayoutInflater; - import android.view.View; - import android.view.ViewGroup; - import android.widget.BaseAdapter; - import android.widget.ImageView; - import android.widget.TextView; - - public class HorizontalListViewAdapter extends BaseAdapter{ - private int[] mIconIDs; - private String[] mTitles; - private Context mContext; - private LayoutInflater mInflater; - Bitmap iconBitmap; - private int selectIndex = –1; - - public HorizontalListViewAdapter(Context context, String[] titles, int[] ids){ - this.mContext = context; - this.mIconIDs = ids; - this.mTitles = titles; - mInflater=(LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);//LayoutInflater.from(mContext); - } - @Override - public int getCount() { - return mIconIDs.length; - } - @Override - public Object getItem(int position) { - return position; - } - - @Override - public long getItemId(int position) { - return position; - } - - @Override - public View getView(int position, View convertView, ViewGroup parent) { - - ViewHolder holder; - if(convertView==null){ - holder = new ViewHolder(); - convertView = mInflater.inflate(R.layout.horizontal_list_item, null); - holder.mImage=(ImageView)convertView.findViewById(R.id.img_list_item); - holder.mTitle=(TextView)convertView.findViewById(R.id.text_list_item); - convertView.setTag(holder); - }else{ - holder=(ViewHolder)convertView.getTag(); - } - if(position == selectIndex){ - convertView.setSelected(true); - }else{ - convertView.setSelected(false); - } - - holder.mTitle.setText(mTitles[position]); - iconBitmap = getPropThumnail(mIconIDs[position]); - holder.mImage.setImageBitmap(iconBitmap); - - return convertView; - } - - private static class ViewHolder { - private TextView mTitle ; - private ImageView mImage; - } - private Bitmap getPropThumnail(int id){ - Drawable d = mContext.getResources().getDrawable(id); - Bitmap b = BitmapUtil.drawableToBitmap(d); - // Bitmap bb = BitmapUtil.getRoundedCornerBitmap(b, 100); - int w = mContext.getResources().getDimensionPixelOffset(R.dimen.thumnail_default_width); - int h = mContext.getResources().getDimensionPixelSize(R.dimen.thumnail_default_height); - - Bitmap thumBitmap = ThumbnailUtils.extractThumbnail(b, w, h); - - return thumBitmap; - } - public void setSelectIndex(int i){ - selectIndex = i; - } - } 下面是效果图： ![](http://img.blog.csdn.net/20140315182924656?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQveWFuemkxMjI1NjI3/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center) 下图是一个item被选定后，另一个item获得了焦点: ![](http://img.blog.csdn.net/20140315183047562?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQveWFuemkxMjI1NjI3/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center) 下面是横向时的截图: ![](http://img.blog.csdn.net/20140315183137906?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQveWFuemkxMjI1NjI3/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center) 要点如下: 1、可以说这个HorizontalListView是完美的，但美中不足的并不是其他人说的不能点击、晃动、加载不全的问题，而是这个横向Listview的高度，如果你设成wrap_cotent那么将会占据整个屏幕，**即使你将它适配器里的view的高度限制死，限制成很小，这个HorizontalListView的高度依然是全屏**。本文代码里，我把图片缩略图弄成100dip，所以把这个HorizontalListView的高度设为了150dip。 2、在适配器里，我填充了一个图片，下面是文字。为了能让浏览图片时item有反应，搞了一个selector，它的用法详见[这里](http://blog.csdn.net/shakespeare001/article/details/7788400). 但一开始在点击时完全没有反应，参考这里： [http://blog.csdn.net/ljz2009y/article/details/18820071](http://blog.csdn.net/ljz2009y/article/details/18820071) 为此我的selector如下： <?xml version=”1.0″ encoding=”utf-8″?> 将自然状态下的背景放到了最后，但点击浏览时依然没有作用。**其实最根本原因是在布局文件里horizontal_list_item.xml要让这个布局能够clickable，即：android:clickable=”true”** 3、上一步完成了，还需要点击即select一个item时，让它变色并且保持住，然后点击另外一个item时，让之前得item恢复默认背景。为了实现这个问题，我曾作如下尝试： **[java]** [view plain](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[copy](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[print](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[?](http://blog.csdn.net/yanzi1225627/article/details/21294553#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/237690)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/237690/fork) <div> </div> </div> </div> - “font-family: ‘Comic Sans MS’; font-size: 18px;”>// if(olderSelectView == null){ - // olderSelectView = view; - // }else{ - // olderSelectView.setSelected(false); - // olderSelectView = null; - // } - // olderSelectView = view; - // view.setSelected(true); 即在click监听里，保存上一个选中的view。遗憾的是这种方法会造成item的选中状态造成混乱，比如第一个item选中了，同时第5个item也莫名其妙的被选中了。上述情况发生在滑动时，即一屏显示不完的情况下。当我横屏时，在所有的item都能一次性显示出来情况下，用上述方法么问题。后来我想到，这可以是适配器里的缓存机制造成的，**最好不要再listview适配器外对item作修改，即便修改则一定要调适配器的: hListViewAdapter.notifyDataSetChanged();通知刷新view，毕竟适配器才是view的提供者**。参考这位大大的文章:[http://longyi-java.iteye.com/blog/976067](http://longyi-java.iteye.com/blog/976067) 在适配器里加了一个接口保存选中的索引，然后再getView函数里进行判断。如果是选中的item，则将布局设为选中状态即可，horizontal_list_item.xml里的Linearlayout就会自动加载那个selector了。而无需像这个参考链接里对每个item的元素分别设置状态。</div> <div> 4、BitmapUtil是个工具类，负责将id转成一个bitmap，然后用android自带的ThumbnailUtils去提取缩略图。 </div> <div> 5、之所以horizontal_list_item布局里要设置padding是为了选中item时，整个item有种被圈住的感觉，而不是光下面一点变色。 </div> <div> 源码下载:[http://download.csdn.net/detail/yanzi1225627/7046295](http://download.csdn.net/detail/yanzi1225627/7046295)</div> <div> 欢迎Android爱好者加群 <div id="group_name" class="group_name usrInputFont"> **Android您问我讲-2，** </div> **群号:****19241311,备注：yanzi** </div> <div> </div> <div> ———————————本文系原创，转载请注明作者:yanzi1225627 </div> <div> </div> <div> </div> <div> 源码下载:[http://download.csdn.net/detail/yanzi1225627/7046295](http://download.csdn.net/detail/yanzi1225627/7046295) </div> <div> 源码下载:[http://download.csdn.net/detail/yanzi1225627/7046295](http://download.csdn.net/detail/yanzi1225627/7046295) </div>