onTouch onTouchEvent 与 onClick三者调用先后分析

看代码，这里初始化了一个自定义的TextView，为它设了OnTouchListener和OnClickListener分别对应onTouch和onClick方法：

public class MainActivity extends AppCompatActivity implements View.OnClickListener, View.OnTouchListener {    private static final String TAG = "MainActivity";    private MyTextView myTextView;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        myTextView = (MyTextView) findViewById(R.id.mytextview);        myTextView.setOnClickListener(this);        myTextView.setOnTouchListener(this);    }    @Override    public void onClick(View view) {        Log.d(TAG,"onClick");    }    @Override    public boolean onTouch(View view, MotionEvent motionEvent) {        Log.d(TAG,"onTouch");        return false;    }}

在自定义的TextView中,我们设置了OnTouchEvent监听

public class MyTextView extends TextView {    private static final String TAG = "MyTextView";    public MyTextView(Context context) {        super(context);    }    public MyTextView(Context context, AttributeSet attrs) {        super(context, attrs);    }    public MyTextView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);    }    //第一步    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        setMeasuredDimension(measureWidth(widthMeasureSpec),measureHeight(heightMeasureSpec));    }    private int measureHeight(int measureSpec) {        int result = 0;        int mode = MeasureSpec.getMode(measureSpec);        int size = MeasureSpec.getSize(measureSpec);        if (mode == MeasureSpec.EXACTLY){            result = size;        }        else {            result = 200;            if (mode == MeasureSpec.AT_MOST){                result = Math.min(result,size);            }        }        return result;    }    private int measureWidth(int measureSpec) {        int result = 0;        int mode = MeasureSpec.getMode(measureSpec);        int size = MeasureSpec.getSize(measureSpec);        if (mode == MeasureSpec.EXACTLY){            result = size;        }        else {            result = 200;            if (mode == MeasureSpec.AT_MOST){                result = Math.min(result,size);            }        }        return result;    }     //第二步    @Override    protected void onDraw(Canvas canvas) {        //绘制文本内容前        super.onDraw(canvas);        //绘制文本内容后    }    @Override    public boolean onTouchEvent(MotionEvent event) {        Log.d(TAG,"onTouchEvent");        return super.onTouchEvent(event);    }}

可以看到这三个监听方法我们都打了Log，那我们在下运行过程：

02-16 04:23:48.566 25076-25076/lwp.myview D/MainActivity: onTouch02-16 04:23:48.566 25076-25076/lwp.myview D/MyTextView: onTouchEvent02-16 04:23:48.577 25076-25076/lwp.myview D/MainActivity: onTouch02-16 04:23:48.577 25076-25076/lwp.myview D/MyTextView: onTouchEvent02-16 04:23:48.584 25076-25076/lwp.myview D/MainActivity: onTouch02-16 04:23:48.585 25076-25076/lwp.myview D/MyTextView: onTouchEvent02-16 04:23:48.585 25076-25076/lwp.myview D/SettingsInterface:  from settings cache , name = sound_effects_enabled , value = 002-16 04:23:48.585 25076-25076/lwp.myview D/MainActivity: onClick

这里我们看到，(1)onTouch最先执行，(2)然后是onTouchEvent，由于onTouch返回了false所以onTouchEvent可以执行，在经历若干次的(1)(2)重复之后，当我手抬起的时候，才会进行onClick操作，对于OnTouch(Activity中setOnTouchListener)->onTouchEvent(view中)->onClick(Activity中setOnClickListener)我们是没有疑问的，这是在onTouchEvent 返回super.onTouchEvent(event)的情况下并且onTouch返回false，但是如果onTouchEvent返回了false（onTouch返回true我就不说了，因为它一旦返回true，onClick和onTouchEvent就根本不会执行），那么点击这个TextView一次，无论长按多久，在一次down-(move)-up里，只会提示一次：

02-16 23:50:00.078 17772-17772/lwp.myview D/MainActivity: onTouch02-16 23:50:00.088 17772-17772/lwp.myview D/MyTextView: onTouchEvent

好的，让我们看下这三个按，移，抬，更加深入的看下：

    @Override    public boolean onTouchEvent(MotionEvent event) {        Log.d(TAG,"onTouchEvent");        switch (event.getAction()){            case MotionEvent.ACTION_DOWN:                Log.d(TAG,"ACTION_DOWN");                break;            case MotionEvent.ACTION_MOVE:                Log.d(TAG,"ACTION_MOVE");                break;            case MotionEvent.ACTION_UP:                Log.d(TAG,"ACTION_UP");                break;        }//        return super.onTouchEvent(event);        return false;//        return false;    }

Log如下：

02-16 23:53:40.589 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:53:40.589 17772-17772/lwp.myview D/MyTextView: ACTION_DOWN

好的，这样我们就发现了，当onTouchEvent返回了false，那也就是它在接受到down事件之后返回了false，之后的move，up也就不会交给onTouchEvent处理了，自然就打印一次；那如果是return了true的话，照这个理解，应该是down,up,move都会执行，并且会执行多次，那我们看下：

02-16 23:57:06.467 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.485 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.485 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.500 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.500 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.517 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.517 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.534 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.534 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.562 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.562 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.620 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.620 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.656 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.656 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.666 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.666 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.684 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.685 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.706 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.707 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.733 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.733 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.756 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.756 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.773 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.773 17772-17772/lwp.myview D/MyTextView: ACTION_MOVE02-16 23:57:06.779 17772-17772/lwp.myview D/MyTextView: onTouchEvent02-16 23:57:06.779 17772-17772/lwp.myview D/MyTextView: ACTION_UP

看结果，确实如此。
由此，我们的出结论：
1.onTouch返回true，则onTouchEvent和onClick都不会执行；
2.onTouch(onTouchListener)返回false，如果onTouchEvent不是返回super.onTouchEvent(event);也就算是说不管onTouchEvent返回true还是false，onClick(onCLickListener)都不会执行，这可以从super的源码看出（源码里会进行判断执行到OnCLickListener）,而且我们知道onClick执行也就会在触摸抬起(up)的时候执行；