Activity的runOnUiThread原理剖析

调用方法顺序图：

runOnUiThread（）-----》post(Runnable r)----》sendMessageDelayed(Message msg,longdelayMillis)------》endMessageAtTime(Message msg,longuptimeMillis)--》nqueueMessage(MessageQueue queue, Message msg,longuptimeMillis)

最后核心代码在：

Handler的dispatchMessage方法：

public void dispatchMessage(Message msg) {

if(msg.callback !=null) {

handleCallback(msg);

}else{

if(mCallback!=null) {

if(mCallback.handleMessage(msg)) {

return;

}

}

handleMessage(msg);

}

}