为了加强鼠标响应事件,Android提供了GestureDetector手势识别类。通过GestureDetector.OnGestureListener来获取当前被触发的操作手势(Single Tap Up、Show Press、Long Press、Scroll、Down、Fling),具体包括以下几种:
boolean onDoubleTap(MotionEvent e)
解释:双击的第二下Touch down时触发
boolean onDoubleTapEvent(MotionEvent e)
解释:双击的第二下Touch down和up都会触发,可用e.getAction()区分。
boolean onDown(MotionEvent e)
解释:Touch down时触发
boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY)
解释:Touch了滑动一点距离后,up时触发。
void onLongPress(MotionEvent e)
解释:Touch了不移动一直Touch down时触发
boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY)
解释:Touch了滑动时触发。
void onShowPress(MotionEvent e)
解释:Touch了还没有滑动时触发 (与onDown,onLongPress比较,onDown只要Touch down一定立刻触发。
而Touchdown后过一会没有滑动先触发onShowPress再是onLongPress。
所以Touchdown后一直不滑动,onDown->onShowPress->onLongPress这个顺序触发。
boolean onSingleTapConfirmed(MotionEvent e)
boolean onSingleTapUp(MotionEvent e)
解释:上面这两个函数都是在touch down后又没有滑动(onScroll),又没有长按(onLongPress),然后Touchup时触发。
点击一下非常快的(不滑动)Touchup:
onDown->onSingleTapUp->onSingleTapConfirmed
点击一下稍微慢点的(不滑动)Touchup:
onDown->onShowPress->onSingleTapUp->onSingleTapConfirmed
使用GestureDetector需要在View中重写onTouchEvent事件,例如:
GestureDetector mGesture = null; @Override public boolean onTouch(View v, MotionEvent event) { // TODO Auto-generated method stub return mGesture.onTouchEvent(event); }
package com.jiubang.android.gesturetest; import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.View; import android.view.GestureDetector.SimpleOnGestureListener; import android.view.View.OnTouchListener; import android.widget.Button; public class GestureActivity extends Activity implements OnTouchListener { private Button mButton = null; GestureDetector mGesture = null; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Log.i("TEST", "onCreate"); mButton = (Button)findViewById(R.id.button1); mButton.setOnTouchListener(this); mGesture = new GestureDetector(this, new GestureListener()); } @Override public boolean onTouch(View v, MotionEvent event) { // TODO Auto-generated method stub return mGesture.onTouchEvent(event); } class GestureListener extends SimpleOnGestureListener { @Override public boolean onDoubleTap(MotionEvent e) { // TODO Auto-generated method stub Log.i("TEST", "onDoubleTap"); return super.onDoubleTap(e); } @Override public boolean onDown(MotionEvent e) { // TODO Auto-generated method stub Log.i("TEST", "onDown"); return super.onDown(e); } @Override public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { // TODO Auto-generated method stub Log.i("TEST", "onFling:velocityX = " + velocityX + " velocityY" + velocityY); return super.onFling(e1, e2, velocityX, velocityY); } @Override public void onLongPress(MotionEvent e) { // TODO Auto-generated method stub Log.i("TEST", "onLongPress"); super.onLongPress(e); } @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { // TODO Auto-generated method stub Log.i("TEST", "onScroll:distanceX = " + distanceX + " distanceY = " + distanceY); return super.onScroll(e1, e2, distanceX, distanceY); } @Override public boolean onSingleTapUp(MotionEvent e) { // TODO Auto-generated method stub Log.i("TEST", "onSingleTapUp"); return super.onSingleTapUp(e); } } }