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初学Android,手势检测(四十七)

2012-09-15 15:56 281 查看
手势是用户触摸屏幕的连续出触碰行为

使用Android的手势检测只需要两个步骤

1.创建一个GestureDetector对象.创建对象时必须实现一个GestureDetector.OnGestureListener监听器实例

2.为应用程序的Activity的TouchEvent 事件绑定监听器,在事件处理中指定把Activity(或特定组件)上的TouchEvent事件交给GestureDetector处理

下面通过一个例子来熟悉一下OnGestureListener的各个事件

package WangLi.IO.GestureTest;

import android.app.Activity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.GestureDetector.OnGestureListener;
import android.view.MotionEvent;
import android.widget.Toast;

public class GestureTest extends Activity implements OnGestureListener
{
//定义手势检测器实例
GestureDetector detector;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//创建手势检测器
detector = new GestureDetector(this);
}

@Override
public boolean onTouchEvent(MotionEvent me)
{
return detector.onTouchEvent(me);
}

//用户轻触触摸屏,由1个MotionEvent ACTION_DOWN触发
@Override
public boolean onDown(MotionEvent arg0) {
// TODO Auto-generated method stub
Toast.makeText(this, "onDown", 8000).show();
return false;
}

//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
//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
@Override
public boolean onFling(MotionEvent arg0, MotionEvent arg1, float arg2,
float arg3) {
// TODO Auto-generated method stub
Toast.makeText(this, "onFling", 8000).show();
return false;
}

//用户长按触摸屏,由多个MotionEvent ACTION_DOWN触发
@Override
public void onLongPress(MotionEvent arg0) {
// TODO Auto-generated method stub
Toast.makeText(this, "onLongPress", 8000).show();
}

//用户按下触摸屏,并拖动,由1个MotionEvent ACTION_DOWN, 多个ACTION_MOVE触发
@Override
public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2,
float arg3) {
// TODO Auto-generated method stub
Toast.makeText(this, "onScroll", 8000).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
@Override
public void onShowPress(MotionEvent arg0) {
// TODO Auto-generated method stub
Toast.makeText(this, "onShowPress", 8000).show();
}

//用户(轻触触摸屏后)松开,由一个1个MotionEvent ACTION_UP触发
@Override
public boolean onSingleTapUp(MotionEvent arg0) {
// TODO Auto-generated method stub
Toast.makeText(this, "onSingleTapUp", 8000).show();
return false;
}
}

package WangLi.IO.GestureTest;

import android.app.Activity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.GestureDetector.OnGestureListener;
import android.view.MotionEvent;
import android.widget.Toast;

public class GestureTest extends Activity implements OnGestureListener
{
//定义手势检测器实例
GestureDetector detector;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//创建手势检测器
detector = new GestureDetector(this);
}

@Override
public boolean onTouchEvent(MotionEvent me)
{
return detector.onTouchEvent(me);
}

//用户轻触触摸屏,由1个MotionEvent ACTION_DOWN触发
@Override
public boolean onDown(MotionEvent arg0) {
// TODO Auto-generated method stub
Toast.makeText(this, "onDown", 8000).show();
return false;
}

//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
//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
@Override
public boolean onFling(MotionEvent arg0, MotionEvent arg1, float arg2,
float arg3) {
// TODO Auto-generated method stub
Toast.makeText(this, "onFling", 8000).show();
return false;
}

//用户长按触摸屏,由多个MotionEvent ACTION_DOWN触发
@Override
public void onLongPress(MotionEvent arg0) {
// TODO Auto-generated method stub
Toast.makeText(this, "onLongPress", 8000).show();
}

//用户按下触摸屏,并拖动,由1个MotionEvent ACTION_DOWN, 多个ACTION_MOVE触发
@Override
public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2,
float arg3) {
// TODO Auto-generated method stub
Toast.makeText(this, "onScroll", 8000).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
@Override
public void onShowPress(MotionEvent arg0) {
// TODO Auto-generated method stub
Toast.makeText(this, "onShowPress", 8000).show();
}

//用户(轻触触摸屏后)松开,由一个1个MotionEvent ACTION_UP触发
@Override
public boolean onSingleTapUp(MotionEvent arg0) {
// TODO Auto-generated method stub
Toast.makeText(this, "onSingleTapUp", 8000).show();
return false;
}
}


上面的事件触发条件比较清晰,可以完成以后自己试试

来源:http://blog.csdn.net/lee576/article/details/7979436

 
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