事件分發學習總結2

佈局結構

所有事件返回值都爲：return super.TouchEvent(event)

E/ActivityToucEvent: dispatchTouchEvent: 0
E/ParentLayout: dispatchTouchEvent: 0
E/ParentLayout: onInterceptTouchEvent: 0
E/NestedParentLayout: dispatchTouchEvent: 0
E/NestedParentLayout: onInterceptTouchEvent: 0
E/ChildView: dispatchTouchEvent: 0
E/ChildView: onTouchEvent: 0
E/NestedParentLayout: onTouchEvent: 0
E/ParentLayout: onTouchEvent: 0
E/ActivityToucEvent: onTouchEvent: 0
E/ActivityToucEvent: dispatchTouchEvent: 1
E/ActivityToucEvent: onTouchEvent: 1

底層View是具有事件的優先消費權的,onTouchEvent最先被調用

ChildView onTouchEvent返回true

E/ActivityToucEvent: dispatchTouchEvent: 0
E/ParentLayout: dispatchTouchEvent: 0
E/ParentLayout: onInterceptTouchEvent: 0
E/NestedParentLayout: dispatchTouchEvent: 0
E/NestedParentLayout: onInterceptTouchEvent: 0
E/ChildView: dispatchTouchEvent: 0
E/ChildView: onTouchEvent: 0
E/ActivityToucEvent: dispatchTouchEvent: 1
E/ParentLayout: dispatchTouchEvent: 1
E/ParentLayout: onInterceptTouchEvent: 1
E/NestedParentLayout: dispatchTouchEvent: 1
E/NestedParentLayout: onInterceptTouchEvent: 1
E/ChildView: dispatchTouchEvent: 1
E/ChildView: onTouchEvent: 1

跟上面對比發現：

• 如果View 沒有對 ACTION_DOWN 進行消費，此次點擊的後續事件不會傳遞過來；
• 如果 View 消費了 ACTION_DOWN ，此次點擊的後續事件會直接給這個 View，這裏的後續事件指的是 ACTION_MOVE 和 ACTION_UP 事件；此時，其父 ViewGroup 的 onIntercept 函數仍會被調用，仍能進行攔截，但它自己的 onIntercept 不會被調用了；

NestedParentLayout onInterceptTouchEvent返回true

E/ActivityToucEvent: dispatchTouchEvent: 0
E/ParentLayout: dispatchTouchEvent: 0
E/ParentLayout: onInterceptTouchEvent: 0
E/NestedParentLayout: dispatchTouchEvent: 0
E/NestedParentLayout: onInterceptTouchEvent: 0
E/NestedParentLayout: onTouchEvent: 0
E/ParentLayout: onTouchEvent: 0
E/ActivityToucEvent: onTouchEvent: 0
E/ActivityToucEvent: dispatchTouchEvent: 1
E/ActivityToucEvent: onTouchEvent: 1

若攔截事件但在onTouchEvent中未消費(返回true)，事件還是會通過onTouchEvent 向上傳遞

NestedParentLayout dispatchTouchEvent返回false

E/ActivityToucEvent: dispatchTouchEvent: 0
E/ParentLayout: dispatchTouchEvent: 0
E/ParentLayout: onInterceptTouchEvent: 0
E/NestedParentLayout: dispatchTouchEvent: 0
E/ParentLayout: onTouchEvent: 0
E/ActivityToucEvent: onTouchEvent: 0
E/ActivityToucEvent: dispatchTouchEvent: 1
E/ActivityToucEvent: onTouchEvent: 1

若dispatchTouchEvent返回false，則本層不再向下傳遞，將事件傳遞給上層onTouchEvent