this means:

    Log.i("AsyncTask / Handler created ON: " + Thread.currentThread().getId());
    Log.i("Main Looper: " + Looper.getMainLooper().getThread().getId() + "      myLooper: "+ Looper.myLooper().getThread().getId());

    new AsyncTask<Void, Void, Void>() {

        @Override
        protected Void doInBackground(Void... params) {
            Log.i("doInBackground ran ON: " + Thread.currentThread().getId());
            // I m in the background, all is normal

            handler.post(new Runnable() {

                @Override
                public void run() {
                    Log.i("Handler posted runnable ON: " + Thread.currentThread().getId());
                    // this is the correct thread, that onPostExecute should be on
                }
            });

            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            Log.i("onPostExecute ran ON: " + Thread.currentThread().getId());
            // this CAN be the wrong thread in certain situations
        }

    }.execute();

如果从上述坏情况来看,产出将考虑这样的内容:。

    AsyncTask / Handler created ON: 16
    Main Looper: 1      myLooper: 16
    doInBackground ran ON: 12
    onPostExecute ran ON: 1
    Handler posted runnable ON: 16

<><>, 编号为AsyncTask>。

as shown this can be mitigated using a Handler.post(Runnable) in my specific case the duality of my "UI thread" situation was caused by the fact that I was creating a dialog in response to a JavaScript interface method called from a WebView, basically: the WebView had its own "UI thread" and that was the one that i was currently running on..

如果有同样的问题。 在我的案件中结案

www.un.org/spanish/ecosoc 简要解释:

1. Running AsynckTask for the very first time on non UI thread with looper leads to loading AsyncTask.class and initialization sHandler to handler constructed on that non UI looper.
2. Now sHandler is connected to that non UI thread for ANY instance of AsyncTask subclasses and onPreExecute, onProgressUpdate and onPostExecute methods will be invoked on that non UI thread (unless AsyncTask.class will be unloaded)
3. Any attempt to deal with UI inside any of the above methods will lead to crash with android.view.ViewRootImpl$CalledFromWrongThreadException
4. To avoid such situation one should always run (at least for the very first time) AsyncTask on UI thread in order to let AsyncTask s sHandler-field be initialized with UI s looper

www.un.org/spanish/ecosoc 故事:

有两个生产图:A - main android app and B - some utilty app.

一体化之后,我们收到了许多坠毁事件:

android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.

http://strong>AsynckTask.onPostExecute()

经过一些调查,似乎在其<>HandlerThread<>/strong>内使用了AsyncTask。

The traces was found in AsyncTask s source code:

private static final InternalHandler sHandler = new InternalHandler();

This is the handler which is used to send onPostExecute() to UI thread.

This handler is static and it will be initialized during class loading i.e. first new AsyncTask() appearance

这意味着,onPostExecute将永远张贴到这个深层:new AsyncTask()第一次被征召(除非AsyncTask.class将卸下,再装上)

In my case the flow was something like this:

1 - starting app A
2 - initializing B form A
3 - B creates its own HandlerThread and launches AsyncTask <- now onPostExecute wil be posted to this HandlerThread no matter where from an instance of AsyncTask will be launched in future
4 - create AsyncTask in the app A for a long operation and update UI in its onPostExecute
5 - when executing onPostExecute() the CalledFromWrongThreadException is thrown

The AsyncTask class must be loaded on the UI thread. This is done automatically as of JELLY_BEAN. The task instance must be created on the UI thread. execute(Params...) must be invoked on the UI thread.

希望能够有助于澄清局势