Android Activity向右滑动返回

package com.kincai.store.ui;
import com.kincai.store.utils.LogTest;
import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.VelocityTracker;
/**
* 
* @company KCS互联网有限公司
* 
* @author kincai
* 
* @description baseActivity
*
* @project Kincai_Store
*
* @package com.kincai.store.ui
*
* @time 2015-7-13 上午10:18:29
*
*/
public class BaseActivity extends Activity {
// 手指上下滑动时的最小速度
private static final int YSPEED_MIN = 1000;
// 手指向右滑动时的最小距离
private static final int XDISTANCE_MIN = 50;
// 手指向上滑或下滑时的最小距离
private static final int YDISTANCE_MIN = 66;
private static final String TAG = "BaseActivity";
// 记录手指按下时的横坐标。
private float xDown;
// 记录手指按下时的纵坐标。
private float yDown;
// 记录手指移动时的横坐标。
private float xMove;
// 记录手指移动时的纵坐标。
private float yMove;
// 用于计算手指滑动的速度。
private VelocityTracker mVelocityTracker;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
LogTest.LogMsg(TAG, "BaseActivity-onCreate");
}
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
createVelocityTracker(event);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
xDown = event.getRawX();
yDown = event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
xMove = event.getRawX();
yMove = event.getRawY();
// 滑动的距离
int distanceX = (int) (xMove - xDown);
int distanceY = (int) (yMove - yDown);
// 获取顺时速度
int ySpeed = getScrollVelocity();
// 关闭Activity需满足以下条件：
// 1.x轴滑动的距离 XDISTANCE_MIN
// 2.y轴滑动的距离在YDISTANCE_MIN范围内
// 3.y轴上（即上下滑动的速度）<XSPEED_MIN，如果大于，则认为用户意图是在上下滑动而非左滑结束Activity
if (distanceX   XDISTANCE_MIN
&& (distanceY < YDISTANCE_MIN && distanceY   -YDISTANCE_MIN)
&& ySpeed < YSPEED_MIN) {
finish();
}
break;
case MotionEvent.ACTION_UP:
recycleVelocityTracker();
break;
default:
break;
}
return super.dispatchTouchEvent(event);
}
/**
* 创建VelocityTracker对象，并将触摸界面的滑动事件加入到VelocityTracker当中。
* 
* @param event
* 
*/
private void createVelocityTracker(MotionEvent event) {
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
}
/**
* 回收VelocityTracker对象。
*/
private void recycleVelocityTracker() {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
/**
* 
* @return 滑动速度，以每秒钟移动了多少像素值为单位。
*/
private int getScrollVelocity() {
//1000速度
mVelocityTracker.computeCurrentVelocity(1000);
int velocity = (int) mVelocityTracker.getYVelocity();
return Math.abs(velocity);
}
@Override
protected void onStart() {
// TODO Auto-generated method stub
super.onStart();
LogTest.LogMsg(TAG, "BaseActivity-onStart");
}
@Override
protected void onResume() {
// TODO Auto-generated method stub
super.onResume();
LogTest.LogMsg(TAG, "BaseActivity-onResume");
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
LogTest.LogMsg(TAG, "BaseActivity-onPause");
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
LogTest.LogMsg(TAG, "BaseActivity-onDestroy");
}
}