onTouch与onClick事件的关系

这几天遇到点关于Android的触摸事件相关的，还跟onClick有关，暂且记下：

LinearLayout分别设置了onTouchListener，onClickListener，onLongClickListener及onTouchEvent回调

1、在屏幕上触摸之后基本的执行流程如下：

onTouch,action=0
onTouchEvent,action=0
onTouch,action=2
onTouchEvent,action=2
onTouch,action=2
onTouchEvent,action=2
onTouch,action=1
onTouchEvent,action=1
onClick

也就是先说onTouchListener是最先被触发的，然后是本身的onTouchEvent回调；当最后的up事件发生并被onTouchEvent处理后才会触发onClickListener。

2、把onTouchEvent回调中的super.onTouchEvent去除，直接返回true；则流程如下：

onTouch,action=0
onTouchEvent,action=0
onTouch,action=2
onTouchEvent,action=2
onTouch,action=2
onTouchEvent,action=2
onTouch,action=1
onTouchEvent,action=1

可以看到onClickListener永远无法被触发，也侧面说明了对onClick的触发是在onTouchEvent回调中来实现的。

3、长按屏幕，流程如下：

onTouch,action=0
onTouchEvent,action=0
onTouch,action=2
onTouchEvent,action=2
onTouch,action=2
onTouchEvent,action=2
onLongClick
onTouch,action=2
onTouchEvent,action=2
onTouch,action=2
onTouchEvent,action=2
onTouch,action=1
onTouchEvent,action=1
onClick

当长按的时候，无需到up就会触发onLongClick的响应，但之后也会继续触发onClick的响应。

4、但如果在onLongClick中返回true，则流程如下，即只在中间触发了onLongClick，之后会继续响应touch，但当up的时候就不会再触发onClick

onTouch,action=0

onTouchEvent,action=0
onTouch,action=2
onTouchEvent,action=2
onTouch,action=2
onTouchEvent,action=2
onLongClick
onTouch,action=2
onTouchEvent,action=2
onTouch,action=2
onTouchEvent,action=2
onTouch,action=1
onTouchEvent,action=1

测试代码如下：

1. public class MainActivity extends Activity {
2. @Override
3. protected void onCreate(Bundle savedInstanceState) {
4. super.onCreate(savedInstanceState);
5. setContentView(R.layout.activity_main);
6. FrameLayout frame = (FrameLayout)findViewById(R.id.container);
7. LinearLayoutTest line = new LinearLayoutTest(this);
8. line.setOnClickListener(new ClickListener());
9. line.setOnLongClickListener(new LongClickListener());
10. line.setOnTouchListener(new TouchListener());
11. line.setLongClickable(true);
12. frame.addView(line);
13. }
14. public class ClickListener implements OnClickListener {
15. @Override
16. public void onClick(View v) {
17. Log.e("test","onClick");
18. }
19. }
20. public class LongClickListener implements OnLongClickListener{
21. @Override
22. public boolean onLongClick(View v) {
23. Log.e("test","onLongClick");
24. return true;
25. }
26. }
27. public class TouchListener implements OnTouchListener{
28. @Override
29. public boolean onTouch(View v, MotionEvent event) {
30. Log.e("test","onTouch,action="+event.getAction());
31. return false;
32. }
33. }
34. }

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        FrameLayout frame = (FrameLayout)findViewById(R.id.container);
        LinearLayoutTest line = new LinearLayoutTest(this);
        line.setOnClickListener(new ClickListener());
        line.setOnLongClickListener(new LongClickListener());
        line.setOnTouchListener(new TouchListener());
        line.setLongClickable(true);
        frame.addView(line);
    }
    public class ClickListener implements OnClickListener {
        @Override
        public void onClick(View v) {
            Log.e("test","onClick");
        }
    }
    public class LongClickListener implements OnLongClickListener{
        @Override
        public boolean onLongClick(View v) {
            Log.e("test","onLongClick");
            return true;
        }
    }
    public class TouchListener implements OnTouchListener{
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            Log.e("test","onTouch,action="+event.getAction());
            return false;
        }
    }
}

1. public class LinearLayoutTest extends LinearLayout{
2. public LinearLayoutTest(Context context) {
3. super(context);
4. }
5. @Override
6. public boolean onTouchEvent(MotionEvent event) {
7. Log.e("test","onTouchEvent,action="+event.getAction());
8. return super.onTouchEvent(event);
9. }
10. }