package org.sunday.slidingreturn; 
import com.example.slidingreturn.R; 
import android.app.Activity; 
import android.content.Intent; 
import android.os.Bundle; 
import android.view.MotionEvent; 
import android.view.VelocityTracker; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.view.View.OnTouchListener; 
import android.widget.Button; 
import android.widget.LinearLayout; 
/** 
* 
* @author sunday 
* 2014-1-4 
* zhengchao1937@163.com 
*/ 
public class SecondActivity extends Activity implements OnTouchListener { 
//手指向右滑動時的最小速度 
private static final int XSPEED_MIN = 200; 
//手指向右滑動時的最小距離 
private static final int XDISTANCE_MIN = 150; 
//記錄手指按下時的橫坐標(biāo)。 
private float xDown; 
//記錄手指移動時的橫坐標(biāo)。 
private float xMove; 
//用于計算手指滑動的速度。 
private VelocityTracker mVelocityTracker; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
setContentView(R.layout.activity_second); 
Button btn = (Button) findViewById(R.id.btn_second); 
btn.setOnClickListener(new OnClickListener() { 
@Override 
public void onClick(View v) { 
startActivity(new Intent(SecondActivity.this, ThirdActivity.class)); 
//設(shè)置切換動畫，從右邊進入，左邊退出 
overridePendingTransition(R.anim.in_from_right, R.anim.out_to_left); 
} 
}); 
LinearLayout ll = (LinearLayout) findViewById(R.id.ll_second); 
ll.setOnTouchListener(this); 
} 
// 轉(zhuǎn)載請說明出處：http://blog.csdn.net/ff20081528/article/details/17845753 
@Override 
public boolean onTouch(View v, MotionEvent event) { 
createVelocityTracker(event); 
switch (event.getAction()) { 
case MotionEvent.ACTION_DOWN: 
xDown = event.getRawX(); 
break; 
case MotionEvent.ACTION_MOVE: 
xMove = event.getRawX(); 
//活動的距離 
int distanceX = (int) (xMove - xDown); 
//獲取順時速度 
int xSpeed = getScrollVelocity(); 
//當(dāng)滑動的距離大于我們設(shè)定的最小距離且滑動的瞬間速度大于我們設(shè)定的速度時，返回到上一個activity 
if(distanceX > XDISTANCE_MIN && xSpeed > XSPEED_MIN) { 
finish(); 
} 
break; 
case MotionEvent.ACTION_UP: 
recycleVelocityTracker(); 
break; 
default: 
break; 
} 
return true; 
} 
/** 
* 創(chuàng)建VelocityTracker對象，并將觸摸content界面的滑動事件加入到VelocityTracker當(dāng)中。 
* 
* @param event 
* 
*/ 
private void createVelocityTracker(MotionEvent event) { 
if (mVelocityTracker == null) { 
mVelocityTracker = VelocityTracker.obtain(); 
} 
mVelocityTracker.addMovement(event); 
} 
/** 
* 回收VelocityTracker對象。 
*/ 
private void recycleVelocityTracker() { 
mVelocityTracker.recycle(); 
mVelocityTracker = null; 
} 
/** 
* 獲取手指在content界面滑動的速度。 
* 
* @return 滑動速度，以每秒鐘移動了多少像素值為單位。 
*/ 
private int getScrollVelocity() { 
mVelocityTracker.computeCurrentVelocity(1000); 
int velocity = (int) mVelocityTracker.getXVelocity(); 
return Math.abs(velocity); 
} 
}