为activity增加左右手势识别

android开发中为activity增加左右手势识别，如右滑关闭当前页面

/*
  *  for左右手势
  *  1.复制下面的内容到目标Activity
  *  2.目标Activity的onCreate()调用initGesture()
  *  3.目标Activity需implements OnTouchListener, OnGestureListener
  */
 private GestureDetector mGestureDetector;
 private int verticalMinDistance = 180;
 private int minVelocity         = 0;

 private void initGesture() {
     mGestureDetector = new GestureDetector((OnGestureListener) this);
 }

 public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {

     if (e1.getX() - e2.getX() > verticalMinDistance && Math.abs(velocityX) > minVelocity) {

         // 切换Activity
         // Intent intent = new Intent(ViewSnsActivity.this, UpdateStatusActivity.class);
         // startActivity(intent);
         //Toast.makeText(this, "向左手势", Toast.LENGTH_SHORT).show();
     } else if (e2.getX() - e1.getX() > verticalMinDistance && Math.abs(velocityX) > minVelocity) {

         // 切换Activity
         // Intent intent = new Intent(ViewSnsActivity.this, UpdateStatusActivity.class);
         // startActivity(intent);
         //Toast.makeText(this, "向右手势", Toast.LENGTH_SHORT).show();
         finish();
         overridePendingTransition(R.anim.push_right_in, R.anim.push_right_out);
     }

     return false;
 }

 @Override
 public void onLongPress(MotionEvent arg0) {
     // TODO Auto-generated method stub

 }

 @Override
 public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2,
         float arg3) {
     // TODO Auto-generated method stub
     return false;
 }

 @Override
 public void onShowPress(MotionEvent arg0) {
     // TODO Auto-generated method stub

 }

 @Override
 public boolean onSingleTapUp(MotionEvent arg0) {
     // TODO Auto-generated method stub
     return false;
 }

 @Override
 public boolean onTouch(View v, MotionEvent event) {
     // TODO Auto-generated method stub
     return mGestureDetector.onTouchEvent(event);
 }

 @Override
 public boolean onDown(MotionEvent arg0) {
     // TODO Auto-generated method stub
     return false;
 }

 @Override
 public boolean dispatchTouchEvent(MotionEvent ev) {
     mGestureDetector.onTouchEvent(ev);
     return super.dispatchTouchEvent(ev);
}