首页 > 代码库 > Android的编程学习笔记——手势编程初探（GestureDetector）
Android的编程学习笔记——手势编程初探（GestureDetector）
Android sdk给我们提供了GestureDetector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。
GestureDetector提供了两个接口：OnGestrueListener、OnDoubleTapListener，从接口的名称来看，前者是手势监听器，后者是双击手势监听器。
OnGestureListener接口含有6个回调方法：
1、onDown(MotionEvent e)
2、onSingleTapUp(MotionEvent e)
3、onShowPress(MotionEvent e)
4、onLongPress(MotionEvent e)
5、onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)
6、onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)
OnDoubleTapListener接口含有3个回调方法：
1、onDoubleTap(MotionEvent e)
2、onDoubleTapEvent(MotionEvent e)
3、onSingleTapConfirmed(MotionEvent e)
为使手势编程更加简洁，Android SDK提供了SimpleOnGestureListener这个内部类，它继承了OnGestureListener、OnDoubleTapListener两个接口，并实现了所有的回调方法，只不过方法体为空，需要程序员在应用程序中重写需要的方法。
以下用一个程序实例来演示SimpleOnGestureListener的用法，以及各回调方法的效果。实例程序界面放置了TextView用来显示屏幕触摸事件的坐标、位移、速度等信息。
- 界面XML文件代码（activity_gesture_test.xml）
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:id="@+id/container" 4 android:layout_width="match_parent" 5 android:layout_height="match_parent" 6 android:orientation="vertical" > 7 8 <LinearLayout 9 android:layout_width="fill_parent" 10 android:layout_height="wrap_content" 11 android:orientation="horizontal" > 12 13 <LinearLayout 14 android:layout_width="0dp" 15 android:layout_height="wrap_content" 16 android:layout_weight="1" 17 android:background="#ccc" 18 android:orientation="vertical" > 19 20 <TextView 21 android:id="@+id/showX" 22 android:layout_width="fill_parent" 23 android:layout_height="wrap_content" 24 android:text="X:" /> 25 26 <TextView 27 android:id="@+id/showY" 28 android:layout_width="fill_parent" 29 android:layout_height="wrap_content" 30 android:text="Y:" /> 31 </LinearLayout> 32 33 <LinearLayout 34 android:layout_width="0dp" 35 android:layout_height="wrap_content" 36 android:layout_weight="1" 37 android:background="#ddd" 38 android:orientation="vertical" > 39 40 <TextView 41 android:id="@+id/showXV" 42 android:layout_width="fill_parent" 43 android:layout_height="wrap_content" 44 android:text="XV:" /> 45 46 <TextView 47 android:id="@+id/showYV" 48 android:layout_width="fill_parent" 49 android:layout_height="wrap_content" 50 android:text="YV:" /> 51 </LinearLayout> 52 </LinearLayout> 53 54 <TextView 55 android:layout_width="fill_parent" 56 android:layout_height="wrap_content" 57 android:text="Scroll Gesture" /> 58 59 <LinearLayout 60 android:layout_width="fill_parent" 61 android:layout_height="wrap_content" 62 android:orientation="horizontal" > 63 64 <LinearLayout 65 android:layout_width="0dp" 66 android:layout_height="wrap_content" 67 android:layout_weight="1" 68 android:background="#ccc" 69 android:orientation="vertical" > 70 71 <TextView 72 android:id="@+id/scrollX1" 73 android:layout_width="fill_parent" 74 android:layout_height="wrap_content" 75 android:text="e1.X:" /> 76 77 <TextView 78 android:id="@+id/scrollY1" 79 android:layout_width="fill_parent" 80 android:layout_height="wrap_content" 81 android:text="e1.Y:" /> 82 83 <TextView 84 android:id="@+id/distanceX" 85 android:layout_width="fill_parent" 86 android:layout_height="wrap_content" 87 android:text="distanceX:" /> 88 </LinearLayout> 89 90 <LinearLayout 91 android:layout_width="0dp" 92 android:layout_height="wrap_content" 93 android:layout_weight="1" 94 android:background="#ddd" 95 android:orientation="vertical" > 96 97 <TextView 98 android:id="@+id/scrollX2" 99 android:layout_width="fill_parent"100 android:layout_height="wrap_content"101 android:text="e2.X:" />102 103 <TextView104 android:id="@+id/scrollY2"105 android:layout_width="fill_parent"106 android:layout_height="wrap_content"107 android:text="e2.Y:" />108 109 <TextView110 android:id="@+id/distanceY"111 android:layout_width="fill_parent"112 android:layout_height="wrap_content"113 android:text="distanceY:" />114 </LinearLayout>115 </LinearLayout>116 117 </LinearLayout>
- java程序代码（GestureTest.java）
1 package org.kit.test.dataio; 2 3 import android.app.Activity; 4 import android.os.Bundle; 5 import android.util.Log; 6 import android.view.GestureDetector; 7 import android.view.GestureDetector.SimpleOnGestureListener; 8 import android.view.MotionEvent; 9 import android.view.View; 10 import android.view.View.OnTouchListener; 11 import android.widget.LinearLayout; 12 import android.widget.TextView; 13 import android.widget.Toast; 14 15 public class GestureTest extends Activity implements OnTouchListener { 16 17 GestureDetector detector; 18 19 TextView posX, posY, velX, velY; 20 TextView scrollX1, scrollY1, scrollX2, scrollY2, _distanceX, _distanceY; 21 22 @Override 23 protected void onCreate(Bundle savedInstanceState) { 24 // TODO Auto-generated method stub 25 super.onCreate(savedInstanceState); 26 setContentView(R.layout.activity_gesture_test); 27 28 detector = new GestureDetector(this, new MySimpleGestureDetector()); 29 30 LinearLayout ll = (LinearLayout) findViewById(R.id.container); 31 ll.setOnTouchListener(this); 32 ll.setClickable(true); 33 ll.setLongClickable(true); 34 35 posX = (TextView) findViewById(R.id.showX); 36 posY = (TextView) findViewById(R.id.showY); 37 38 velX = (TextView) findViewById(R.id.showXV); 39 velY = (TextView) findViewById(R.id.showYV); 40 41 scrollX1 = (TextView) findViewById(R.id.scrollX1); 42 scrollY1 = (TextView) findViewById(R.id.scrollY1); 43 scrollX2 = (TextView) findViewById(R.id.scrollX2); 44 scrollY2 = (TextView) findViewById(R.id.scrollY2); 45 _distanceX = (TextView) findViewById(R.id.distanceX); 46 _distanceY = (TextView) findViewById(R.id.distanceY); 47 48 } 49 50 @Override 51 public boolean onTouch(View v, MotionEvent event) { 52 posX.setText("X:" + event.getX()); 53 posY.setText("Y:" + event.getY()); 54 // 55 return detector.onTouchEvent(event); 56 } 57 58 // 内部类inner class 59 private class MySimpleGestureDetector extends SimpleOnGestureListener { 60 61 @Override 62 public boolean onDoubleTap(MotionEvent e) { 63 // TODO Auto-generated method stub 64 65 Toast.makeText(GestureTest.this, "double tap!", Toast.LENGTH_SHORT).show(); 66 return super.onDoubleTap(e); 67 } 68 69 @Override 70 public boolean onDown(MotionEvent event) { 71 // TODO Auto-generated method stub 72 73 posX.setText("X:" + event.getX()); 74 posY.setText("Y:" + event.getY()); 75 return false; 76 } 77 78 @Override 79 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { 80 // TODO Auto-generated method stub 81 velX.setText("XV:" + velocityX); 82 velY.setText("YV:" + velocityY); 83 84 Toast.makeText( getApplicationContext(), 85 "Fling!\ne1.X=" + e1.getX() + " e1.Y=" + e1.getY() + "\ne2.X=" + e2.getX() + " e2.Y=" 86 + e2.getY(), 87 Toast.LENGTH_LONG).show(); 88 89 return false; 90 } 91 92 @Override 93 public void onLongPress(MotionEvent arg0) { 94 // TODO Auto-generated method stub 95 96 Toast.makeText(getApplicationContext(), "Long Press", Toast.LENGTH_SHORT).show(); 97 } 98 99 @Override100 public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {101 // TODO Auto-generated method stub102 103 scrollX1.setText("e1.X:" + e1.getX());104 scrollY1.setText("e1.Y:" + e1.getY());105 scrollX2.setText("e2.X:" + e2.getX());106 scrollY2.setText("e2.Y:" + e2.getY());107 _distanceX.setText("distanceX:" + distanceX);108 _distanceY.setText("distanceY:" + distanceY);109 110 return false;111 }112 113 @Override114 public void onShowPress(MotionEvent arg0) {115 // TODO Auto-generated method stub116 Toast.makeText(getApplicationContext(), "Show Press!", Toast.LENGTH_LONG).show();117 118 }119 120 @Override121 public boolean onSingleTapUp(MotionEvent e) {122 // TODO Auto-generated method stub123 124 Toast.makeText(getApplicationContext(), "Single Tap", Toast.LENGTH_LONG).show();125 return false;126 }127 128 @Override129 public boolean onSingleTapConfirmed(MotionEvent e) {130 // TODO Auto-generated method stub131 132 Toast.makeText(getApplicationContext(), "Single Tap confirmed", Toast.LENGTH_LONG).show();133 134 return super.onSingleTapConfirmed(e);135 }136 137 @Override138 public boolean onDoubleTapEvent(MotionEvent e) {139 // TODO Auto-generated method stub140 switch (e.getAction()) {141 case MotionEvent.ACTION_DOWN:142 Toast.makeText(getApplicationContext(), "double click down", Toast.LENGTH_SHORT).show();143 break;144 case MotionEvent.ACTION_UP:145 Toast.makeText(getApplicationContext(), "double click up", Toast.LENGTH_SHORT).show();146 break;147 148 default:149 break;150 }151 return super.onDoubleTapEvent(e);152 }153 }154 155 }
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