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android – GestureDetector onScroll()问题(执行3次)（android onresume执行两次）

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android – GestureDetector onScroll()问题(执行3次)（android onresume执行两次）

android – GestureDetector onScroll()问题(执行3次)（android onresume执行两次）

我有这段代码来使用GestureDetector检测滚动手势.它工作,除了它检测滚动活动3次而不是一次.

如何只检测一次？它记录了滚动活动(log.i行)3次,并播放声音(mp.start)3次而不是一次….也导致我的应用程序强行关闭.

  public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {

        //get x and Y co-ordinates and log it as info. 
        float x1 = e1.getX();
        float y1 = e1.getY();
        float x2 = e2.getX();
        float y2 = e2.getY();       
        Log.i("Scroll_Gesture", "Scrolled from: (" + x1 + "," + y1 + " to " + x2 +"," + y2 + ")");

        mp = MediaPlayer.create(this, R.raw.scroll_success);        
        mp.start();

       //start success page
        Intent intent = new Intent(this, ScrollSuccess.class);
        startActivity(intent); 
        return false;
    }

解决方法:

“onScroll()”将被多次调用.
它被调用的次数取决于用户完成的滚动操作.

如果您希望代码块在每个滚动操作的开头只运行一次,那么您必须添加一个条件,如下所示：

   float scrollstartX1, scrollStartY1;

   public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
           float distanceY) {
    // get x and Y co-ordinates and log it as info.
       if (scrollstartX1 != e1.getX() || scrollStartY1 != e1.getY()) {
           scrollstartX1 = e1.getX();
           scrollStartY1 = e1.getY();
               //***************************************
           //code run only once for a scroll action...
               //****************************************
       }
           float x2 = e2.getX();
           float y2 = e2.getY();
           Log.i("Scroll_Gesture", "Scrolled from: (" + scrollstartX1 + "," + scrollStartY1 + " to "
                   + x2 + "," + y2 + ")");

           mp = MediaPlayer.create(this, R.raw.scroll_success);
           mp.start();

           // start success page
           Intent intent = new Intent(this, ScrollSuccess.class);
           startActivity(intent);

       return false;
   }

Android GestureDetector实现手势滑动效果

Android GestureDetector实现手势滑动效果

本文实例为大家分享了Android GestureDetector实现手势滑动的具体代码，供大家参考，具体内容如下

目标效果：

 

程序运行，手指在屏幕上从左往右或者从右往左滑动超过一定距离，就会吐司输出滑动方向和距离。

1.activity_main.xml页面放置一个ImageView控件。

activity_main.xml页面：

<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"
  tools:context=".MainActivity" >
 
  <ImageView
    android:id="@+id/ivShow"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:src="@drawable/ic_launcher" />
 
</RelativeLayout>

2.MainActivity.java页面实现滑动方法。

MainActivity.java页面：

package com.example.gesturedetector;
 
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
import android.widget.Toast;
 
public class MainActivity extends Activity {
 
 private ImageView ivShow;
 private GestureDetector gestureDetector;
 
 class myGestureListener extends SimpleOnGestureListener{
 @Override
 /*识别滑动，第一个参数为刚开始事件，第二个参数为结束事件*/
 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
  float velocityY) {
  if(e1.getX()-e2.getX()>50){
  Toast.makeText(MainActivity.this,"从右往左滑动"+(e1.getX()-e2.getX()),Toast.LENGTH_LONG).show();
  }else if(e2.getX()-e1.getX()>50){
  Toast.makeText(MainActivity.this,"从左往右滑动"+(e2.getX()-e1.getX()),Toast.LENGTH_LONG).show();
  }
  return super.onFling(e1, e2, velocityX, velocityY);
 }
 }
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 
 gestureDetector=new GestureDetector(MainActivity.this,new myGestureListener());
 
 ivShow=(ImageView) findViewById(R.id.ivShow);
 ivShow.setLongClickable(true); //view必须设置为true，否则手势识别无法正确工作
 ivShow.setOnTouchListener(new OnTouchListener() {
 
  
  /*可以捕获到触摸屏幕发生的Event事件*/
  @Override
  public boolean onTouch(View arg0, MotionEvent event) {
  gestureDetector.onTouchEvent(event);//转发
  return false;
  }
 });
 }
}

3.程序较简单，运行就可以显示目标效果了。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。

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Android GestureDetector用户手势检测实例讲解

Android GestureDetector用户手势检测实例讲解

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：

private class gesturelistener implements GestureDetector.OnGestureListener{ 
 
 public boolean onDown(MotionEvent e) { 
  // Todo Auto-generated method stub 
  return false; 
 } 
 
 public void onShowPress(MotionEvent e) { 
  // Todo Auto-generated method stub 
   
 } 
 
 public boolean onSingleTapUp(MotionEvent e) { 
  // Todo Auto-generated method stub 
  return false; 
 } 
 
 public boolean onScroll(MotionEvent e1,MotionEvent e2,float distanceX,float distanceY) { 
  // Todo Auto-generated method stub 
  return false; 
 } 
 
 public void onLongPress(MotionEvent e) { 
  // Todo Auto-generated method stub 
   
 } 
 
 public boolean onFling(MotionEvent e1,float veLocityX,float veLocityY) { 
  // Todo Auto-generated method stub 
  return false; 
 } 
  
}

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,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,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
onDown-----》onScroll----》onScroll----》onScroll----》………----->onFling
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：

GestureDetector.OnGestureListener listener = new GestureDetector.OnGestureListener(){ 
   
 };

也可以构造类：

private class gestureListener implements GestureDetector.OnGestureListener{ 
 
}

2.创建GestureDetector实例mGestureDetector：

构造函数有下面三个，根据需要选择：

GestureDetector gestureDetector=new GestureDetector(GestureDetector.OnGestureListener listener); 
GestureDetector gestureDetector=new GestureDetector(Context context,GestureDetector.OnGestureListener listener); 
GestureDetector gestureDetector=new GestureDetector(Context context,GestureDetector.SimpleOnGestureListener listener); 

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

public boolean onTouch(View v,MotionEvent event) { 
 return mGestureDetector.onTouchEvent(event);  
}

4.控件绑定

TextView tv = (TextView)findViewById(R.id.tv); 
tv.setonTouchListener(this);

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：

<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" 
 tools:context="com.example.gesturedetectorinterface.MainActivity" > 
 
 <TextView 
  android:id="@+id/tv" 
  android:layout_width="fill_parent" 
  android:layout_height="fill_parent" 
  android:layout_margin="50dip" 
  android:background="#ff00ff" 
  android:text="@string/hello_world" /> 
 
</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

public class MainActivity extends Activity implements OnTouchListener{ 
 
 private GestureDetector mGestureDetector;  
  
 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.activity_main); 
   
  mGestureDetector = new GestureDetector(new gestureListener()); //使用派生自OnGestureListener 
   
  TextView tv = (TextView)findViewById(R.id.tv); 
  tv.setonTouchListener(this); 
  tv.setFocusable(true);  
  tv.setClickable(true);  
  tv.setLongClickable(true); 
 } 
  
  
 /* 
  * 在onTouch()方法中，我们调用GestureDetector的onTouchEvent()方法，将捕捉到的MotionEvent交给GestureDetector 
  * 来分析是否有合适的callback函数来处理用户的手势 
  */ 
 public boolean onTouch(View v,MotionEvent event) { 
  return mGestureDetector.onTouchEvent(event);  
 } 
  
 private class gestureListener implements GestureDetector.OnGestureListener{ 
 
  // 用户轻触触摸屏，由1个MotionEvent ACTION_DOWN触发  
  public boolean onDown(MotionEvent e) { 
   Log.i("MyGesture","onDown");  
   Toast.makeText(MainActivity.this,"onDown",Toast.LENGTH_SHORT).show();  
   return false; 
  } 
 
  /* 
   * 用户轻触触摸屏，尚未松开或拖动，由一个1个MotionEvent ACTION_DOWN触发 
   * 注意和onDown()的区别，强调的是没有松开或者拖动的状态 
   * 
   * 而onDown也是由一个MotionEventACTION_DOWN触发的，但是他没有任何限制， 
   * 也就是说当用户点击的时候，首先MotionEventACTION_DOWN，onDown就会执行， 
   * 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 
   * （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。 
   */ 
  public void onShowPress(MotionEvent e) { 
   Log.i("MyGesture","onShowPress");  
   Toast.makeText(MainActivity.this,"onShowPress",Toast.LENGTH_SHORT).show();  
  } 
 
  // 用户（轻触触摸屏后）松开，由一个1个MotionEvent ACTION_UP触发  
  ///轻击一下屏幕，立刻抬起来，才会有这个触发 
  //从名子也可以看出,当然,所以这个事件 就不再响应 
  public boolean onSingleTapUp(MotionEvent e) { 
   Log.i("MyGesture","onSingleTapUp");  
   Toast.makeText(MainActivity.this,"onSingleTapUp",Toast.LENGTH_SHORT).show();  
   return true;  
  } 
 
  // 用户按下触摸屏，并拖动，由1个MotionEvent ACTION_DOWN,多个ACTION_MOVE触发  
  public boolean onScroll(MotionEvent e1,float distanceY) { 
   Log.i("MyGesture22","onScroll:"+(e2.getX()-e1.getX()) +" "+distanceX);  
   Toast.makeText(MainActivity.this,"onScroll",Toast.LENGTH_LONG).show();  
    
   return true;  
  } 
 
  // 用户长按触摸屏，由多个MotionEvent ACTION_DOWN触发  
  public void onLongPress(MotionEvent e) { 
    Log.i("MyGesture","onLongPress");  
    Toast.makeText(MainActivity.this,"onLongPress",Toast.LENGTH_LONG).show();  
  } 
 
  // 用户按下触摸屏、快速移动后松开，由1个MotionEvent ACTION_DOWN,1个ACTION_UP触发  
  public boolean onFling(MotionEvent e1,float veLocityY) { 
   Log.i("MyGesture","onFling");  
   Toast.makeText(MainActivity.this,"onFling",Toast.LENGTH_LONG).show();  
   return true; 
  } 
 }; 
  
 
}

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：

private class gestureListener implements GestureDetector.OnGestureListener,GestureDetector.OnDoubleTapListener{ 
 }

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

//构建GestureDetector实例  
mGestureDetector = new GestureDetector(new gestureListener()); //使用派生自OnGestureListener 
private class gestureListener implements GestureDetector.OnGestureListener{ 
  
} 
 
//设置双击监听器 
mGestureDetector.setonDoubleTapListener(new doubleTapListener()); 
private class doubleTapListener implements 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：
GestureDetector gestureDetector=new GestureDetector(GestureDetector.OnGestureListener listener); 
GestureDetector gestureDetector=new 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：

private class doubleTapListener implements GestureDetector.OnDoubleTapListener{ 
 
 public boolean onSingleTapConfirmed(MotionEvent e) { 
  // Todo Auto-generated method stub 
  return false; 
 } 
 
 public boolean onDoubleTap(MotionEvent e) { 
  // Todo Auto-generated method stub 
  return false; 
 } 
 
 public boolean onDoubleTapEvent(MotionEvent e) { 
  // Todo Auto-generated method stub 
  return false; 
 } 
}

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：

public class MainActivity extends Activity implements OnTouchListener{ 
 
 private GestureDetector mGestureDetector;  
  
 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.activity_main); 
   
 
  mGestureDetector = new GestureDetector(new gestureListener()); //使用派生自OnGestureListener 
  mGestureDetector.setonDoubleTapListener(new doubleTapListener()); 
   
  TextView tv = (TextView)findViewById(R.id.tv); 
  tv.setonTouchListener(this); 
  tv.setFocusable(true);  
  tv.setClickable(true);  
  tv.setLongClickable(true); 
 } 
  
  
 /* 
  * 在onTouch()方法中，我们调用GestureDetector的onTouchEvent()方法，将捕捉到的MotionEvent交给GestureDetector 
  * 来分析是否有合适的callback函数来处理用户的手势 
  */ 
 public boolean onTouch(View v,MotionEvent event) { 
  return mGestureDetector.onTouchEvent(event);  
 } 
  
 //OnGestureListener监听 
 private class gestureListener implements GestureDetector.OnGestureListener{ 
 
  public boolean onDown(MotionEvent e) { 
   Log.i("MyGesture",Toast.LENGTH_SHORT).show();  
   return false; 
  } 
 
  public void onShowPress(MotionEvent e) { 
   Log.i("MyGesture",Toast.LENGTH_SHORT).show();  
  } 
 
  public boolean onSingleTapUp(MotionEvent e) { 
   Log.i("MyGesture",Toast.LENGTH_SHORT).show();  
   return true;  
  } 
 
  public boolean onScroll(MotionEvent e1,Toast.LENGTH_LONG).show();  
    
   return true;  
  } 
 
  public void onLongPress(MotionEvent e) { 
    Log.i("MyGesture",Toast.LENGTH_LONG).show();  
  } 
 
  public boolean onFling(MotionEvent e1,Toast.LENGTH_LONG).show();  
   return true; 
  } 
 }; 
  
 //OnDoubleTapListener监听 
 private class doubleTapListener implements GestureDetector.OnDoubleTapListener{ 
 
  public boolean onSingleTapConfirmed(MotionEvent e) { 
   Log.i("MyGesture","onSingleTapConfirmed");  
   Toast.makeText(MainActivity.this,"onSingleTapConfirmed",Toast.LENGTH_LONG).show(); 
   return true; 
  } 
 
  public boolean onDoubleTap(MotionEvent e) { 
   Log.i("MyGesture","onDoubleTap");  
   Toast.makeText(MainActivity.this,"onDoubleTap",Toast.LENGTH_LONG).show(); 
   return true; 
  } 
 
  public boolean onDoubleTapEvent(MotionEvent e) { 
   Log.i("MyGesture","onDoubleTapEvent");  
   Toast.makeText(MainActivity.this,"onDoubleTapEvent",Toast.LENGTH_LONG).show(); 
   return true; 
  } 
 }; 
}

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：

public class MainActivity extends Activity implements OnTouchListener { 
 
 private GestureDetector mGestureDetector;  
  
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.activity_main); 
   
  mGestureDetector = new GestureDetector(new simpleGestureListener()); 
   
  TextView tv = (TextView)findViewById(R.id.tv); 
  tv.setonTouchListener(this); 
  tv.setFocusable(true);  
  tv.setClickable(true);  
  tv.setLongClickable(true); 
 } 
  
 public boolean onTouch(View v,MotionEvent event) { 
  // Todo Auto-generated method stub 
  return mGestureDetector.onTouchEvent(event);  
 } 
 
 private class simpleGestureListener extends 
   GestureDetector.SimpleOnGestureListener { 
   
  /*****OnGestureListener的函数*****/ 
  public boolean onDown(MotionEvent e) { 
   Log.i("MyGesture","onDown"); 
   Toast.makeText(MainActivity.this,Toast.LENGTH_SHORT) 
     .show(); 
   return false; 
  } 
 
  public void onShowPress(MotionEvent e) { 
   Log.i("MyGesture","onShowPress"); 
   Toast.makeText(MainActivity.this,Toast.LENGTH_SHORT) 
     .show(); 
  } 
 
  public boolean onSingleTapUp(MotionEvent e) { 
   Log.i("MyGesture","onSingleTapUp"); 
   Toast.makeText(MainActivity.this,Toast.LENGTH_SHORT).show(); 
   return true; 
  } 
 
  public boolean onScroll(MotionEvent e1,float distanceY) { 
   Log.i("MyGesture","onScroll:" + (e2.getX() - e1.getX()) + " " 
     + distanceX); 
   Toast.makeText(MainActivity.this,Toast.LENGTH_LONG) 
     .show(); 
 
   return true; 
  } 
 
  public void onLongPress(MotionEvent e) { 
   Log.i("MyGesture","onLongPress"); 
   Toast.makeText(MainActivity.this,Toast.LENGTH_LONG) 
     .show(); 
  } 
 
  public boolean onFling(MotionEvent e1,"onFling"); 
   Toast.makeText(MainActivity.this,Toast.LENGTH_LONG) 
     .show(); 
   return true; 
  } 
   
  /*****OnDoubleTapListener的函数*****/ 
  public boolean onSingleTapConfirmed(MotionEvent e) { 
   Log.i("MyGesture","onSingleTapConfirmed"); 
   Toast.makeText(MainActivity.this,"onDoubleTap"); 
   Toast.makeText(MainActivity.this,Toast.LENGTH_LONG) 
     .show(); 
   return true; 
  } 
 
  public boolean onDoubleTapEvent(MotionEvent e) { 
   Log.i("MyGesture","onDoubleTapEvent"); 
   Toast.makeText(MainActivity.this,Toast.LENGTH_LONG).show(); 
   return true; 
  } 
 
 } 
}

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：

boolean onFling(MotionEvent e1,float veLocityY) 

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    
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:

public class MainActivity extends Activity implements OnTouchListener { 
 
 private GestureDetector mGestureDetector;  
  
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  setContentView(R.layout.activity_main); 
   
  mGestureDetector = new GestureDetector(new simpleGestureListener()); 
   
  TextView tv = (TextView)findViewById(R.id.tv); 
  tv.setonTouchListener(this); 
  tv.setFocusable(true);  
  tv.setClickable(true);  
  tv.setLongClickable(true); 
 } 
  
 public boolean onTouch(View v,MotionEvent event) { 
  // Todo Auto-generated method stub 
  return mGestureDetector.onTouchEvent(event);  
 } 
 
 private class simpleGestureListener extends 
   GestureDetector.SimpleOnGestureListener { 
   
  /*****OnGestureListener的函数*****/ 
 
  final int FLING_MIN_disTANCE = 100,FLING_MIN_VELociTY = 200; 
   
  // 触发条件 ：  
  // 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  
   
  // 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  
  public boolean onFling(MotionEvent e1,float veLocityY) { 
    
    
   if (e1.getX() - e2.getX() > FLING_MIN_disTANCE 
     && Math.abs(veLocityX) > FLING_MIN_VELociTY) { 
    // Fling left  
    Log.i("MyGesture","Fling left"); 
    Toast.makeText(MainActivity.this,"Fling Left",Toast.LENGTH_SHORT).show(); 
   } else if (e2.getX() - e1.getX() > FLING_MIN_disTANCE 
     && Math.abs(veLocityX) > FLING_MIN_VELociTY) { 
    // Fling right  
    Log.i("MyGesture","Fling right"); 
    Toast.makeText(MainActivity.this,"Fling Right",Toast.LENGTH_SHORT).show(); 
   } 
   return true; 
  } 
 
 } 
}

这段代码难度不大,就不再细讲,看下效果：

源码在博客底部给出。

源码地址：GestureDetector手势检测

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程小技巧。

Android ListView与OnItemClickListener和GestureDetector

Android ListView与OnItemClickListener和GestureDetector

我有一个以下ListActivity： 
public class ShowDayActivity extends ListActivity implements OnItemClickListener {
    private GestureDetector gestureDetector;
    private View.OnTouchListener gestureListener;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.day);
        registerForContextMenu(getListView());

        gestureDetector = new GestureDetector(new MyGestureDetector());
        gestureListener = new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v,MotionEvent event) {
                return gestureDetector.onTouchEvent(event);
            }
        };

        getListView().setonItemClickListener(this);
        getListView().setonTouchListener(gestureListener);
    }

    @SuppressWarnings("static-access")
    @Override
    public boolean onoptionsItemSelected(MenuItem item) {
        ...
        return super.onoptionsItemSelected(item);
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {
        ...
        return super.onContextItemSelected(item);
    }

    Override
    public void onItemClick(AdapterView<?> parent,View v,int pos,long id) {
        editEvent(pos);
    }

    class MyGestureDetector extends SimpleOnGestureListener {
        private static final int SWIPE_MIN_disTANCE = 120;
        private static final int SWIPE_MAX_OFF_PATH = 250;
        private static final int SWIPE_THRESHOLD_VELociTY = 200;

        @Override
        public boolean onFling(MotionEvent e1,MotionEvent e2,float veLocityX,float veLocityY) {
            if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH) {
               return false;
            }
            // right to left swipe
            if (e1.getX() - e2.getX() > SWIPE_MIN_disTANCE && Math.abs(veLocityX) > SWIPE_THRESHOLD_VELociTY) {
                Log.d("ICS-Calendar","Fling left");
                return true;
            } else if (e2.getX() - e1.getX() > SWIPE_MIN_disTANCE && Math.abs(veLocityX) > SWIPE_THRESHOLD_VELociTY) {
                Log.d("ICS-Calendar","Fling right");
                return true;
            }

            return false;
        }
    }   
}

listItems上的contextListener(long-click)完美地工作.今天我添加了gestureListener和Detector,它也是这样,但是：

GestureDetector检测到一切都没有了,但是在完成了逻辑之后,会打开上下文菜单,这显然不是我想要的.任何想法我做错了,还是我可以做什么？

解决方法

通常,您需要调用cancelLongPress()方法,并检测到onFling后的所有视图的子项.但是对于AbsListView,这个方法什么也不做:(

但是我已经找到了解决方法：在onFling回调中,处理完所有内容后,为ListView对象执行下一步：

Event cancelEvent = Event.obtain(ev2);
cancelEvent.setAction(MotionEvent.ACTION_UP);
listView.onTouchEvent(cancelEvent);

android p cts camera测试 android.hardware.camera2.cts.CaptureRequestTest#testEdgeModeControl fail

android p cts camera测试 android.hardware.camera2.cts.CaptureRequestTest#testEdgeModeControl fail

fail提示：

07-02 15:07:10 I/ConsoleReporter: [3998000000000000007] Starting armeabi-v7a CtsCameraTestCases with 1 test
cts-tf > 07-02 15:07:10 I/ConsoleReporter: [1/1 armeabi-v7a CtsCameraTestCases 3998000000000000007] android.hardware.camera2.cts.CaptureRequestTest#testEdgeModeControl fail: java.lang.Exception: There were 60 errors:
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [33333333, 33333333], value 62500000 is out of range [32999998, 33666664])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])
  java.lang.Throwable(Test Failed for camera 1: Frame duration must be in the range of [50000000, 50000000], value 62500000 is out of range [49500000, 50500000])

通过抓fps 插件，fps：16.49 ，10000/16.49 = 625
需要修改sensor 驱动文件
.max_framerate = 300,//原来是160

今天的关于android – GestureDetector onScroll()问题(执行3次)和android onresume执行两次的分享已经结束，谢谢您的关注，如果想了解更多关于Android GestureDetector实现手势滑动效果、Android GestureDetector用户手势检测实例讲解、Android ListView与OnItemClickListener和GestureDetector、android p cts camera测试 android.hardware.camera2.cts.CaptureRequestTest#testEdgeModeControl fail的相关知识，请在本站进行查询。

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