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) {

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

           // 切換Activity
           // Intent intent = new Intent(ViewSnsActivity.this, UpdateStatusActivity.class);
           // startActivity(intent);
        //Toast.makeText(this, "向右手勢", 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);
  }