其中Layout里的onInterceptTouchEvent默认返回值是false,这样touch事件会传递到View控件，Layout里的onTouch默认返回值是false, View里的onTouch默认返回值是true,当我们手指点击屏幕时候，先调用ACTION_DOWN事件,当onTouch里返回值是true的时候，onTouch回继续调用ACTION_UP事件，如果onTouch里返回值是false，那么onTouch只会调用ACTION_DOWN而不调用ACTION_UP.
xml：
<?xml version="1.0" encoding="utf-8"?>
<com.tutor.touch.MyLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<com.tutor.touch.MyView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />
</com.tutor.touch.MyLayout>
MyLayout.java
public class MyLayout extends FrameLayout {
public MyLayout(Context context){
super(context);
}
public MyLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
Log.e(TouchDemoActivity.TAG, "MyLayout onInterceptTouchEvent.");
Log.e(TouchDemoActivity.TAG,"MyLayout onInterceptTouchEvent default return "
+ super.onInterceptTouchEvent(ev));
return super.onInterceptTouchEvent(ev);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
Log.e(TouchDemoActivity.TAG, "MyLayout onTouchEvent.");
Log.e(TouchDemoActivity.TAG,"MyLayout onTouchEvent default return "
+ super.onTouchEvent(event));
return super.onTouchEvent(event);
}
}
MyView .java
public class MyView extends Button {
public MyView(Context context){
super(context);
}
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
Log.e(TouchDemoActivity.TAG, "MyView onTouchEvent.");
Log.e(TouchDemoActivity.TAG,"MyView onTouchEvent default return "
+ super.onTouchEvent(event));
return super.onTouchEvent(event);
}
点击红色区域，触发了MyView里的onTouch事件
点击绿色区域，则触发了MyLayout里的onTouch事件，查看logcat，如下图:
上面俩个截图都是用系统默认值，可以得出结论:onInterceptTouchEvent默认返回值是false,MyLayout里onTouchEvent默认返回值是false，所以只消费了ACTION_DOWN事件，MyView里onTouch默认返回值是true,调用了俩次:ACTION_DOW,ACTION_UP。