我寫了一個UI介面，最外層是OuterLinearLayout，內層是InnerLayout，最裡層是TargetButton，下面是實驗輸出的日誌：

2018-11-25 22:15:27.288 28703-28703/work.cloud.com.myappcloudwork D/ttt: dispatchTouchEvent in OuterLinearLayout
2018-11-25 22:15:27.289 28703-28703/work.cloud.com.myappcloudwork D/ttt: onInterceptTouchEvent in OuterLinearLayout
2018-11-25 22:15:27.290 28703-28703/work.cloud.com.myappcloudwork D/ttt: dispatchTouchEvent in InnerLayout
2018-11-25 22:15:27.290 28703-28703/work.cloud.com.myappcloudwork D/ttt: onInterceptTouchEvent in InnerLayout
2018-11-25 22:15:27.291 28703-28703/work.cloud.com.myappcloudwork D/ttt: dispatchTouchEvent in TargetButton
2018-11-25 22:15:27.292 28703-28703/work.cloud.com.myappcloudwork D/ttt: onTouchEvent in TargetButton
2018-11-25 22:15:27.294 28703-28703/work.cloud.com.myappcloudwork D/ttt: onTouchEvent in InnerLayout
2018-11-25 22:15:27.295 28703-28703/work.cloud.com.myappcloudwork D/ttt: onTouchEvent in OuterLinearLayout

從日誌可以看出，touch事件經過每一層View時，先執行dispatchTouchEvent方法，然後執行onInterceptTouchEvent，以此情形直至佈局的最裡層，我這裡是一個普通View，叫TargetButton；然後可以看出從內向外以此執行onTouchEvent方法。

如果某層做了攔截，即該層ViewGroup的onInterceptTouchEvent返回值設為true，那麼touch事件不再向下傳遞，實驗輸入日誌為：

2018-11-25 22:30:03.303 29787-29787/work.cloud.com.myappcloudwork D/ttt: dispatchTouchEvent in OuterLinearLayout
2018-11-25 22:30:03.304 29787-29787/work.cloud.com.myappcloudwork D/ttt: onInterceptTouchEvent in OuterLinearLayout
2018-11-25 22:30:03.304 29787-29787/work.cloud.com.myappcloudwork D/ttt: dispatchTouchEvent in InnerLayout
2018-11-25 22:30:03.305 29787-29787/work.cloud.com.myappcloudwork D/ttt: onInterceptTouchEvent in InnerLayout
2018-11-25 22:30:03.305 29787-29787/work.cloud.com.myappcloudwork D/ttt: onTouchEvent in InnerLayout
2018-11-25 22:30:03.306 29787-29787/work.cloud.com.myappcloudwork D/ttt: onTouchEvent in OuterLinearLayout

可以看到TargetButton的onTouchEvent的方法沒有得到執行；而攔截層以上的，以此執行onTouchEvent。

未完，待續。。。下面幾張圖不太能理解。

參考：https://www.cnblogs.com/RGogoing/p/4657722.html

可以移步到https://www.cnblogs.com/huozhong/p/5899687.html，這篇更通俗