用户手势检测-GestureDetector使用详解

一、概述

当用户触摸屏幕的时候，会产生许多手势，例如down，up，scroll，filing等等。
一般情况下，我们知道View类有个View.OnTouchListener内部接口，通过重写他的onTouch(View v, MotionEvent event)方法，我们可以处理一些touch事件，但是这个方法太过简单，如果需要处理一些复杂的手势，用这个接口就会很麻烦（因为我们要自己根据用户触摸的轨迹去判断是什么手势）。
Android sdk给我们提供了GestureDetector（Gesture：手势Detector：识别）类，通过这个类我们可以识别很多的手势，主要是通过他的onTouchEvent(event)方法完成了不同手势的识别。虽然他能识别手势，但是不同的手势要怎么处理，应该是提供给程序员实现的。

GestureDetector这个类对外提供了两个接口和一个外部类
接口：OnGestureListener，OnDoubleTapListener
内部类:SimpleOnGestureListener

这个外部类，其实是两个接口中所有函数的集成，它包含了这两个接口里所有必须要实现的函数而且都已经重写，但所有方法体都是空的；不同点在于：该类是static class，程序员可以在外部继承这个类，重写里面的手势处理方法。

下面我们先看OnGestureListener接口；

二、GestureDetector.OnGestureListener—接口

1、基本讲解

如果我们写一个类并implements OnGestureListener，会提示有几个必须重写的函数，加上之后是这个样子的：

**[java]** [view plain](http://blog.csdn.net/harvic880925/article/details/39520901#)[copy](http://blog.csdn.net/harvic880925/article/details/39520901#)[![在CODE上查看代码片](https://code.csdn.net/assets/CODE_ico.png)](https://code.csdn.net/snippets/475851)[![派生到我的代码片](https://code.csdn.net/assets/ico_fork.svg)](https://code.csdn.net/snippets/475851/fork)

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- <span class="keyword">private</span> <span class="keyword">class</span> gesturelistener <span class="keyword">implements</span> GestureDetector.OnGestureListener{

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onDown(MotionEvent e) {

- <span class="comment">// TODO Auto-generated method stub</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">void</span> onShowPress(MotionEvent e) {

- <span class="comment">// TODO Auto-generated method stub</span>

- 
- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onSingleTapUp(MotionEvent e) {

- <span class="comment">// TODO Auto-generated method stub</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onScroll(MotionEvent e1, MotionEvent e2,

- <span class="keyword">float</span> distanceX, <span class="keyword">float</span> distanceY) {

- <span class="comment">// TODO Auto-generated method stub</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">void</span> onLongPress(MotionEvent e) {

- <span class="comment">// TODO Auto-generated method stub</span>

- 
- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onFling(MotionEvent e1, MotionEvent e2, <span class="keyword">float</span> velocityX,

- <span class="keyword">float</span> velocityY) {

- <span class="comment">// TODO Auto-generated method stub</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- }

可见，这里总共重写了六个函数，这些函数都在什么情况下才会触发呢，下面讲一下：

**OnDown(MotionEvent e)：**用户按下屏幕就会触发；
**onShowPress(MotionEvent e)：**如果是按下的时间超过瞬间，而且在按下的时候没有松开或者是拖动的，那么onShowPress就会执行，具体这个瞬间是多久，我也不清楚呃……
**onLongPress(MotionEvent e)：**长按触摸屏，超过一定时长，就会触发这个事件
触发顺序：
onDown->onShowPress->onLongPress
**onSingleTapUp(MotionEvent e)：**从名子也可以看出,一次单独的轻击抬起操作,也就是轻击一下屏幕，立刻抬起来，才会有这个触发，当然,如果除了Down以外还有其它操作,那就不再算是Single操作了,所以也就不会触发这个事件
触发顺序：
点击一下非常快的（不滑动）Touchup：
onDown->onSingleTapUp->onSingleTapConfirmed
点击一下稍微慢点的（不滑动）Touchup：
onDown->onShowPress->onSingleTapUp->onSingleTapConfirmed
**onFling(MotionEvent e1, MotionEvent e2, float velocityX,float velocityY) ：**滑屏，用户按下触摸屏、快速移动后松开，由1个MotionEvent ACTION_DOWN, 多个ACTION_MOVE, 1个ACTION_UP触发
参数解释：
e1：第1个ACTION_DOWN MotionEvent
e2：最后一个ACTION_MOVE MotionEvent
velocityX：X轴上的移动速度，像素/秒
velocityY：Y轴上的移动速度，像素/秒
**onScroll(MotionEvent e1, MotionEvent e2,float distanceX, float distanceY)：**在屏幕上拖动事件。无论是用手拖动view，或者是以抛的动作滚动，都会多次触发,这个方法在ACTION_MOVE动作发生时就会触发
滑屏：手指触动屏幕后，稍微滑动后立即松开
拖动
onDown——》onScroll—-》onScroll——》onFiling

可见，无论是滑屏，还是拖动，影响的只是中间OnScroll触发的数量多少而已，最终都会触发onFling事件！

2、实例

要使用GestureDetector，有三步要走：

1、创建OnGestureListener监听函数：
可以使用构造实例：

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- GestureDetector.OnGestureListener listener = <span class="keyword">new</span> GestureDetector.OnGestureListener(){

- 
- };

也可以构造类：

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- <span class="keyword">private</span> <span class="keyword">class</span> gestureListener <span class="keyword">implements</span> GestureDetector.OnGestureListener{

- 
- }

2、创建GestureDetector实例mGestureDetector：

构造函数有下面三个，根据需要选择：

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- GestureDetector gestureDetector=<span class="keyword">new</span> GestureDetector(GestureDetector.OnGestureListener listener);

- GestureDetector gestureDetector=<span class="keyword">new</span> GestureDetector(Context context,GestureDetector.OnGestureListener listener);

- GestureDetector gestureDetector=<span class="keyword">new</span> GestureDetector(Context context,GestureDetector.SimpleOnGestureListener listener);

3、onTouch(View v, MotionEvent event)中拦截：

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- <span class="keyword">public</span> <span class="keyword">boolean</span> onTouch(View v, MotionEvent event) {

- <span class="keyword">return</span> mGestureDetector.onTouchEvent(event);

- }

4、控件绑定

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- TextView tv = (TextView)findViewById(R.id.tv);

- tv.setOnTouchListener(<span class="keyword">this</span>);

现在进入实例阶段：

首先，在主布局页面添加一个textView，并将其放大到整屏，方便在其上的手势识别，代码为：

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- <RelativeLayout xmlns:android=<span class="string">&#8220;http://schemas.android.com/apk/res/android&#8221;</span>

- xmlns:tools=<span class="string">&#8220;http://schemas.android.com/tools&#8221;</span>

- android:layout_width=<span class="string">&#8220;match_parent&#8221;</span>

- android:layout_height=<span class="string">&#8220;match_parent&#8221;</span>

- tools:context=<span class="string">&#8220;com.example.gesturedetectorinterface.MainActivity&#8221;</span> >

- 
- <TextView

- android:id=<span class="string">&#8220;@+id/tv&#8221;</span>

- android:layout_width=<span class="string">&#8220;fill_parent&#8221;</span>

- android:layout_height=<span class="string">&#8220;fill_parent&#8221;</span>

- android:layout_margin=<span class="string">&#8220;50dip&#8221;</span>

- android:background=<span class="string">&#8220;#ff00ff&#8221;</span>

- android:text=<span class="string">&#8220;@string/hello_world&#8221;</span> />

- 
- </RelativeLayout>

然后在JAVA代码中，依据上面的三步走原则，写出代码，并在所有的手势下添加上Toast提示并写上Log

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- <span class="keyword">public</span> <span class="keyword">class</span> MainActivity <span class="keyword">extends</span> Activity <span class="keyword">implements</span> OnTouchListener{

- 
- <span class="keyword">private</span> GestureDetector mGestureDetector;

- 
- 
- <span class="annotation">@Override</span>

- <span class="keyword">protected</span> <span class="keyword">void</span> onCreate(Bundle savedInstanceState) {

- <span class="keyword">super</span>.onCreate(savedInstanceState);

- setContentView(R.layout.activity_main);

- 
- mGestureDetector = <span class="keyword">new</span> GestureDetector(<span class="keyword">new</span> gestureListener()); <span class="comment">//使用派生自OnGestureListener</span>

- 
- TextView tv = (TextView)findViewById(R.id.tv);

- tv.setOnTouchListener(<span class="keyword">this</span>);

- tv.setFocusable(<span class="keyword">true</span>);

- tv.setClickable(<span class="keyword">true</span>);

- tv.setLongClickable(<span class="keyword">true</span>);

- }

- 
- 
- <span class="comment">/* </span>

- <span class="comment">     * 在onTouch()方法中，我们调用GestureDetector的onTouchEvent()方法，将捕捉到的MotionEvent交给GestureDetector </span>

- <span class="comment">     * 来分析是否有合适的callback函数来处理用户的手势 </span>

- <span class="comment">     */</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> onTouch(View v, MotionEvent event) {

- <span class="keyword">return</span> mGestureDetector.onTouchEvent(event);

- }

- 
- <span class="keyword">private</span> <span class="keyword">class</span> gestureListener <span class="keyword">implements</span> GestureDetector.OnGestureListener{

- 
- <span class="comment">// 用户轻触触摸屏，由1个MotionEvent ACTION_DOWN触发   </span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> onDown(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onDown&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onDown&#8221;</span>, Toast.LENGTH_SHORT).show();

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="comment">/*  </span>

- <span class="comment">         * 用户轻触触摸屏，尚未松开或拖动，由一个1个MotionEvent ACTION_DOWN触发  </span>

- <span class="comment">         * 注意和onDown()的区别，强调的是没有松开或者拖动的状态  </span>

- <span class="comment">         * </span>

- <span class="comment">         * 而onDown也是由一个MotionEventACTION_DOWN触发的，但是他没有任何限制，</span>

- <span class="comment">         * 也就是说当用户点击的时候，首先MotionEventACTION_DOWN，onDown就会执行，</span>

- <span class="comment">         * 如果在按下的瞬间没有松开或者是拖动的时候onShowPress就会执行，如果是按下的时间超过瞬间</span>

- <span class="comment">         * （这块我也不太清楚瞬间的时间差是多少，一般情况下都会执行onShowPress），拖动了，就不执行onShowPress。</span>

- <span class="comment">         */</span>

- <span class="keyword">public</span> <span class="keyword">void</span> onShowPress(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onShowPress&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onShowPress&#8221;</span>, Toast.LENGTH_SHORT).show();

- }

- 
- <span class="comment">// 用户（轻触触摸屏后）松开，由一个1个MotionEvent ACTION_UP触发   </span>

- <span class="comment">///轻击一下屏幕，立刻抬起来，才会有这个触发</span>

- <span class="comment">//从名子也可以看出,一次单独的轻击抬起操作,当然,如果除了Down以外还有其它操作,那就不再算是Single操作了,所以这个事件 就不再响应</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> onSingleTapUp(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onSingleTapUp&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onSingleTapUp&#8221;</span>, Toast.LENGTH_SHORT).show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="comment">// 用户按下触摸屏，并拖动，由1个MotionEvent ACTION_DOWN, 多个ACTION_MOVE触发   </span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> onScroll(MotionEvent e1, MotionEvent e2,

- <span class="keyword">float</span> distanceX, <span class="keyword">float</span> distanceY) {

- Log.i(<span class="string">&#8220;MyGesture22&#8221;</span>, <span class="string">&#8220;onScroll:&#8221;</span>+(e2.getX()-e1.getX()) +<span class="string">&#8221;   &#8220;</span>+distanceX);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onScroll&#8221;</span>, Toast.LENGTH_LONG).show();

- 
- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="comment">// 用户长按触摸屏，由多个MotionEvent ACTION_DOWN触发   </span>

- <span class="keyword">public</span> <span class="keyword">void</span> onLongPress(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onLongPress&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onLongPress&#8221;</span>, Toast.LENGTH_LONG).show();

- }

- 
- <span class="comment">// 用户按下触摸屏、快速移动后松开，由1个MotionEvent ACTION_DOWN, 多个ACTION_MOVE, 1个ACTION_UP触发   </span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> onFling(MotionEvent e1, MotionEvent e2, <span class="keyword">float</span> velocityX,

- <span class="keyword">float</span> velocityY) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onFling&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onFling&#8221;</span>, Toast.LENGTH_LONG).show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- };

- 
- 
- }

源码在博客底部给出。

三、GestureDetector.OnDoubleTapListener—接口

1、构建

有两种方式设置双击监听：

方法一：新建一个类同时派生自OnGestureListener和OnDoubleTapListener：

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- <span class="keyword">private</span> <span class="keyword">class</span> gestureListener <span class="keyword">implements</span> GestureDetector.OnGestureListener,GestureDetector.OnDoubleTapListener{

- }

方法二：使用GestureDetector::setOnDoubleTapListener();函数设置监听：

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- <span class="comment">//构建GestureDetector实例   </span>

- mGestureDetector = <span class="keyword">new</span> GestureDetector(<span class="keyword">new</span> gestureListener()); <span class="comment">//使用派生自OnGestureListener</span>

- <span class="keyword">private</span> <span class="keyword">class</span> gestureListener <span class="keyword">implements</span> GestureDetector.OnGestureListener{

- 
- }

- 
- <span class="comment">//设置双击监听器</span>

- mGestureDetector.setOnDoubleTapListener(<span class="keyword">new</span> doubleTapListener());

- <span class="keyword">private</span> <span class="keyword">class</span> doubleTapListener <span class="keyword">implements</span> GestureDetector.OnDoubleTapListener{

- 
- }

注意：大家可以看到无论在方法一还是在方法二中，都需要派生自GestureDetector.OnGestureListener，前面我们说过GestureDetector 的构造函数，如下：

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- GestureDetector gestureDetector=<span class="keyword">new</span> GestureDetector(GestureDetector.OnGestureListener listener);

- GestureDetector gestureDetector=<span class="keyword">new</span> GestureDetector(Context context,GestureDetector.OnGestureListener listener);

- GestureDetector gestureDetector=<span class="keyword">new</span> GestureDetector(Context context,GestureDetector.SimpleOnGestureListener listener);

可以看到，在构造函数中，除了后面要讲的SimpleOnGestureListener 以外的其它两个构造函数都必须是OnGestureListener的实例。所以要想使用OnDoubleTapListener的几个函数，就必须先实现OnGestureListener。

2、函数讲解：

首先看一下OnDoubleTapListener接口必须重写的三个函数：

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- <span class="keyword">private</span> <span class="keyword">class</span> doubleTapListener <span class="keyword">implements</span> GestureDetector.OnDoubleTapListener{

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onSingleTapConfirmed(MotionEvent e) {

- <span class="comment">// TODO Auto-generated method stub</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onDoubleTap(MotionEvent e) {

- <span class="comment">// TODO Auto-generated method stub</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onDoubleTapEvent(MotionEvent e) {

- <span class="comment">// TODO Auto-generated method stub</span>

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- }

**onSingleTapConfirmed(MotionEvent e)：**单击事件。用来判定该次点击是SingleTap而不是DoubleTap，如果连续点击两次就是DoubleTap手势，如果只点击一次，系统等待一段时间后没有收到第二次点击则判定该次点击为SingleTap而不是DoubleTap，然后触发SingleTapConfirmed事件。触发顺序是：OnDown->OnsingleTapUp->OnsingleTapConfirmed
关于onSingleTapConfirmed和onSingleTapUp的一点区别： OnGestureListener有这样的一个方法onSingleTapUp，和onSingleTapConfirmed容易混淆。二者的区别是：onSingleTapUp，只要手抬起就会执行，而对于onSingleTapConfirmed来说，如果双击的话，则onSingleTapConfirmed不会执行。

**onDoubleTap(MotionEvent e)：**双击事件

**onDoubleTapEvent(MotionEvent e)：**双击间隔中发生的动作。指触发onDoubleTap以后，在双击之间发生的其它动作，包含down、up和move事件；下图是双击一下的Log输出：

两点总结：

1、从上图可以看出，在第二下点击时，先触发OnDoubleTap，然后再触发OnDown（第二次点击）

2、其次在触发OnDoubleTap以后，就开始触发onDoubleTapEvent了，onDoubleTapEvent后面的数字代表了当前的事件，0指ACTION_DOWN，1指ACTION_UP，2 指ACTION_MOVE
在上一个例子的基础上，我们再添加一个双击监听类，实现如下：

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    <embed id="ZeroClipboardMovie_13" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_13">
    </embed>
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- <span class="keyword">public</span> <span class="keyword">class</span> MainActivity <span class="keyword">extends</span> Activity <span class="keyword">implements</span> OnTouchListener{

- 
- <span class="keyword">private</span> GestureDetector mGestureDetector;

- 
- 
- <span class="annotation">@Override</span>

- <span class="keyword">protected</span> <span class="keyword">void</span> onCreate(Bundle savedInstanceState) {

- <span class="keyword">super</span>.onCreate(savedInstanceState);

- setContentView(R.layout.activity_main);

- 
- 
- mGestureDetector = <span class="keyword">new</span> GestureDetector(<span class="keyword">new</span> gestureListener()); <span class="comment">//使用派生自OnGestureListener</span>

- mGestureDetector.setOnDoubleTapListener(<span class="keyword">new</span> doubleTapListener());

- 
- TextView tv = (TextView)findViewById(R.id.tv);

- tv.setOnTouchListener(<span class="keyword">this</span>);

- tv.setFocusable(<span class="keyword">true</span>);

- tv.setClickable(<span class="keyword">true</span>);

- tv.setLongClickable(<span class="keyword">true</span>);

- }

- 
- 
- <span class="comment">/* </span>

- <span class="comment">     * 在onTouch()方法中，我们调用GestureDetector的onTouchEvent()方法，将捕捉到的MotionEvent交给GestureDetector </span>

- <span class="comment">     * 来分析是否有合适的callback函数来处理用户的手势 </span>

- <span class="comment">     */</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> onTouch(View v, MotionEvent event) {

- <span class="keyword">return</span> mGestureDetector.onTouchEvent(event);

- }

- 
- <span class="comment">//OnGestureListener监听</span>

- <span class="keyword">private</span> <span class="keyword">class</span> gestureListener <span class="keyword">implements</span> GestureDetector.OnGestureListener{

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onDown(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onDown&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onDown&#8221;</span>, Toast.LENGTH_SHORT).show();

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">void</span> onShowPress(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onShowPress&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onShowPress&#8221;</span>, Toast.LENGTH_SHORT).show();

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onSingleTapUp(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onSingleTapUp&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onSingleTapUp&#8221;</span>, Toast.LENGTH_SHORT).show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onScroll(MotionEvent e1, MotionEvent e2,

- <span class="keyword">float</span> distanceX, <span class="keyword">float</span> distanceY) {

- Log.i(<span class="string">&#8220;MyGesture22&#8221;</span>, <span class="string">&#8220;onScroll:&#8221;</span>+(e2.getX()-e1.getX()) +<span class="string">&#8221;   &#8220;</span>+distanceX);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onScroll&#8221;</span>, Toast.LENGTH_LONG).show();

- 
- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">void</span> onLongPress(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onLongPress&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onLongPress&#8221;</span>, Toast.LENGTH_LONG).show();

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onFling(MotionEvent e1, MotionEvent e2, <span class="keyword">float</span> velocityX,

- <span class="keyword">float</span> velocityY) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onFling&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onFling&#8221;</span>, Toast.LENGTH_LONG).show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- };

- 
- <span class="comment">//OnDoubleTapListener监听</span>

- <span class="keyword">private</span> <span class="keyword">class</span> doubleTapListener <span class="keyword">implements</span> GestureDetector.OnDoubleTapListener{

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onSingleTapConfirmed(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onSingleTapConfirmed&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onSingleTapConfirmed&#8221;</span>, Toast.LENGTH_LONG).show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onDoubleTap(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onDoubleTap&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onDoubleTap&#8221;</span>, Toast.LENGTH_LONG).show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onDoubleTapEvent(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onDoubleTapEvent&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onDoubleTapEvent&#8221;</span>, Toast.LENGTH_LONG).show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- };

- }

双击一下，部分截图如下：

双击所对应的触发事件顺序：

轻轻单击一下，对应的事件触发顺序为：

源码在博客底部给出。

四、GestureDetector.SimpleOnGestureListener—类

它与前两个不同的是：
1、这是一个类，在它基础上新建类的话，要用extends派生而不是用implements继承！
2、OnGestureListener和OnDoubleTapListener接口里的函数都是强制必须重写的，即使用不到也要重写出来一个空函数但在SimpleOnGestureListener类的实例或派生类中不必如此，可以根据情况，用到哪个函数就重写哪个函数，因为SimpleOnGestureListener类本身已经实现了这两个接口的所有函数，只是里面全是空的而已。

下面利用SimpleOnGestureListener类来重新实现上面的几个效果，代码如下：

  <div>
    <embed id="ZeroClipboardMovie_14" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_14">
    </embed>
  </div>
</div>

- <span class="keyword">public</span> <span class="keyword">class</span> MainActivity <span class="keyword">extends</span> Activity <span class="keyword">implements</span> OnTouchListener {

- 
- <span class="keyword">private</span> GestureDetector mGestureDetector;

- 
- <span class="annotation">@Override</span>

- <span class="keyword">protected</span> <span class="keyword">void</span> onCreate(Bundle savedInstanceState) {

- <span class="keyword">super</span>.onCreate(savedInstanceState);

- setContentView(R.layout.activity_main);

- 
- mGestureDetector = <span class="keyword">new</span> GestureDetector(<span class="keyword">new</span> simpleGestureListener());

- 
- TextView tv = (TextView)findViewById(R.id.tv);

- tv.setOnTouchListener(<span class="keyword">this</span>);

- tv.setFocusable(<span class="keyword">true</span>);

- tv.setClickable(<span class="keyword">true</span>);

- tv.setLongClickable(<span class="keyword">true</span>);

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onTouch(View v, MotionEvent event) {

- <span class="comment">// TODO Auto-generated method stub</span>

- <span class="keyword">return</span> mGestureDetector.onTouchEvent(event);

- }

- 
- <span class="keyword">private</span> <span class="keyword">class</span> simpleGestureListener <span class="keyword">extends</span>

- GestureDetector.SimpleOnGestureListener {

- 
- <span class="comment">/*****OnGestureListener的函数*****/</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> onDown(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onDown&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onDown&#8221;</span>, Toast.LENGTH_SHORT)

- .show();

- <span class="keyword">return</span> <span class="keyword">false</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">void</span> onShowPress(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onShowPress&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onShowPress&#8221;</span>, Toast.LENGTH_SHORT)

- .show();

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onSingleTapUp(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onSingleTapUp&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onSingleTapUp&#8221;</span>,

- Toast.LENGTH_SHORT).show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onScroll(MotionEvent e1, MotionEvent e2,

- <span class="keyword">float</span> distanceX, <span class="keyword">float</span> distanceY) {


- + distanceX);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onScroll&#8221;</span>, Toast.LENGTH_LONG)

- .show();

- 
- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">void</span> onLongPress(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onLongPress&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onLongPress&#8221;</span>, Toast.LENGTH_LONG)

- .show();

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onFling(MotionEvent e1, MotionEvent e2, <span class="keyword">float</span> velocityX,

- <span class="keyword">float</span> velocityY) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onFling&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onFling&#8221;</span>, Toast.LENGTH_LONG)

- .show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="comment">/*****OnDoubleTapListener的函数*****/</span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> onSingleTapConfirmed(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onSingleTapConfirmed&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onSingleTapConfirmed&#8221;</span>,

- Toast.LENGTH_LONG).show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onDoubleTap(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onDoubleTap&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onDoubleTap&#8221;</span>, Toast.LENGTH_LONG)

- .show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onDoubleTapEvent(MotionEvent e) {

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;onDoubleTapEvent&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;onDoubleTapEvent&#8221;</span>,

- Toast.LENGTH_LONG).show();

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- }

- }

到此，有关GestureDetector的所有基础知识都讲解完了，下面给出一个小应用——识别用户是向左滑还是向右滑！

源码在博客底部给出。

五、OnFling应用——识别向左滑还是向右滑

这部分就有点意思了，可以说是上面知识的一个小应用，我们利用OnFling函数来识别当前用户是在向左滑还是向右滑，从而打出日志。先看下OnFling的参数：

  <div>
    <embed id="ZeroClipboardMovie_15" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_15">
    </embed>
  </div>
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- <span class="keyword">boolean</span> onFling(MotionEvent e1, MotionEvent e2, <span class="keyword">float</span> velocityX,<span class="keyword">float</span> velocityY)

- 参数解释：

- e1：第<span class="number">1</span>个ACTION_DOWN MotionEvent

- e2：最后一个ACTION_MOVE MotionEvent

- velocityX：X轴上的移动速度，像素/秒

- velocityY：Y轴上的移动速度，像素/秒

首先，先说一下实现的功能：当用户向左滑动距离超过100px，且滑动速度超过100 px/s时,即判断为向左滑动;向右同理.代码如下:

  <div>
    <embed id="ZeroClipboardMovie_16" src="http://static.blog.csdn.net/scripts/ZeroClipboard/ZeroClipboard.swf" type="application/x-shockwave-flash" width="18" height="18" align="middle" name="ZeroClipboardMovie_16">
    </embed>
  </div>
</div>

- <span class="keyword">public</span> <span class="keyword">class</span> MainActivity <span class="keyword">extends</span> Activity <span class="keyword">implements</span> OnTouchListener {

- 
- <span class="keyword">private</span> GestureDetector mGestureDetector;

- 
- <span class="annotation">@Override</span>

- <span class="keyword">protected</span> <span class="keyword">void</span> onCreate(Bundle savedInstanceState) {

- <span class="keyword">super</span>.onCreate(savedInstanceState);

- setContentView(R.layout.activity_main);

- 
- mGestureDetector = <span class="keyword">new</span> GestureDetector(<span class="keyword">new</span> simpleGestureListener());

- 
- TextView tv = (TextView)findViewById(R.id.tv);

- tv.setOnTouchListener(<span class="keyword">this</span>);

- tv.setFocusable(<span class="keyword">true</span>);

- tv.setClickable(<span class="keyword">true</span>);

- tv.setLongClickable(<span class="keyword">true</span>);

- }

- 
- <span class="keyword">public</span> <span class="keyword">boolean</span> onTouch(View v, MotionEvent event) {

- <span class="comment">// TODO Auto-generated method stub</span>

- <span class="keyword">return</span> mGestureDetector.onTouchEvent(event);

- }

- 
- <span class="keyword">private</span> <span class="keyword">class</span> simpleGestureListener <span class="keyword">extends</span>

- GestureDetector.SimpleOnGestureListener {

- 
- <span class="comment">/*****OnGestureListener的函数*****/</span>

- 
- <span class="keyword">final</span> <span class="keyword">int</span> FLING_MIN_DISTANCE = <span class="number">100</span>, FLING_MIN_VELOCITY = <span class="number">200</span>;

- 
- <span class="comment">// 触发条件 ：   </span>

- <span class="comment">// X轴的坐标位移大于FLING_MIN_DISTANCE，且移动速度大于FLING_MIN_VELOCITY个像素/秒   </span>

- 
- <span class="comment">// 参数解释：   </span>

- <span class="comment">// e1：第1个ACTION_DOWN MotionEvent   </span>

- <span class="comment">// e2：最后一个ACTION_MOVE MotionEvent   </span>

- <span class="comment">// velocityX：X轴上的移动速度，像素/秒   </span>

- <span class="comment">// velocityY：Y轴上的移动速度，像素/秒   </span>

- <span class="keyword">public</span> <span class="keyword">boolean</span> onFling(MotionEvent e1, MotionEvent e2, <span class="keyword">float</span> velocityX,

- <span class="keyword">float</span> velocityY) {

- 
- 

- && Math.abs(velocityX) > FLING_MIN_VELOCITY) {

- <span class="comment">// Fling left   </span>

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;Fling left&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;Fling Left&#8221;</span>, Toast.LENGTH_SHORT).show();


- && Math.abs(velocityX) > FLING_MIN_VELOCITY) {

- <span class="comment">// Fling right   </span>

- Log.i(<span class="string">&#8220;MyGesture&#8221;</span>, <span class="string">&#8220;Fling right&#8221;</span>);

- Toast.makeText(MainActivity.<span class="keyword">this</span>, <span class="string">&#8220;Fling Right&#8221;</span>, Toast.LENGTH_SHORT).show();

- }

- <span class="keyword">return</span> <span class="keyword">true</span>;

- }

- 
- }

- }

一、概述#

二、GestureDetector.OnGestureListener—接口#

1、基本讲解#

2、实例#

三、GestureDetector.OnDoubleTapListener—接口#

1、构建#

2、函数讲解：#

四、GestureDetector.SimpleOnGestureListener—类#

五、OnFling应用——识别向左滑还是向右滑#

💬 评论

一、概述

二、GestureDetector.OnGestureListener—接口

1、基本讲解

2、实例

三、GestureDetector.OnDoubleTapListener—接口

1、构建

2、函数讲解：

四、GestureDetector.SimpleOnGestureListener—类

五、OnFling应用——识别向左滑还是向右滑