为什么人们把事情搞得这么难。

这应该足够了。

不要在异步任务上实现onPostExecute，而是在Activity上实现它:

public class MainActivity extends Activity 
{

@Override
public void onCreate(Bundle savedInstanceState) {

    //execute the async task 
    MyAsyncTask task = new MyAsyncTask(){
            protected void onPostExecute(String result) {
                //Do your thing
            }       

    }

    task.execute("Param");

}


}

嗨，你可以做这样的东西:

Create class which implements AsyncTask // TASK public class SomeClass extends AsyncTask<Void, Void, String>> { private OnTaskExecutionFinished _task_finished_event; public interface OnTaskExecutionFinished { public void OnTaskFihishedEvent(String Reslut); } public void setOnTaskFinishedEvent(OnTaskExecutionFinished _event) { if(_event != null) { this._task_finished_event = _event; } } @Override protected void onPreExecute() { super.onPreExecute(); } @Override protected String doInBackground(Void... params) { // do your background task here ... return "Done!"; } @Override protected void onPostExecute(String result) { super.onPostExecute(result); if(this._task_finished_event != null) { this._task_finished_event.OnTaskFihishedEvent(result); } else { Log.d("SomeClass", "task_finished even is null"); } } } Add in Main Activity // MAIN ACTIVITY public class MyActivity extends ListActivity { ... SomeClass _some_class = new SomeClass(); _someclass.setOnTaskFinishedEvent(new _some_class.OnTaskExecutionFinished() { @Override public void OnTaskFihishedEvent(String result) { Toast.makeText(getApplicationContext(), "Phony thread finished: " + result, Toast.LENGTH_SHORT).show(); } }); _some_class.execute(); ... }

有以下几种选择:

Nest the AsyncTask class within your Activity class. Assuming you don't use the same task in multiple activities, this is the easiest way. All your code stays the same, you just move the existing task class to be a nested class inside your activity's class. public class MyActivity extends Activity { // existing Activity code ... private class MyAsyncTask extends AsyncTask<String, Void, String> { // existing AsyncTask code ... } } Create a custom constructor for your AsyncTask that takes a reference to your Activity. You would instantiate the task with something like new MyAsyncTask(this).execute(param1, param2). public class MyAsyncTask extends AsyncTask<String, Void, String> { private Activity activity; public MyAsyncTask(Activity activity) { this.activity = activity; } // existing AsyncTask code ... }

试试这个:

public class SomAsyncTask extends AsyncTask<String, Integer, JSONObject> {

    private CallBack callBack;

    public interface CallBack {
        void async( JSONObject jsonResult );
        void sync( JSONObject jsonResult );
        void progress( Integer... status );
        void cancel();
    }

    public SomAsyncTask(CallBack callBack) {
        this.callBack = callBack;
    }

    @Override
    protected JSONObject doInBackground(String... strings) {

        JSONObject dataJson = null;

        //TODO query, get some dataJson

        if(this.callBack != null)
            this.callBack.async( dataJson );// asynchronize with MAIN LOOP THREAD

        return dataJson;

    }

    @Override
    protected void onProgressUpdate(Integer... values) {
        super.onProgressUpdate(values);

        if(this.callBack != null)
            this.callBack.progress(values);// synchronize with MAIN LOOP THREAD

    }

    @Override
    protected void onPostExecute(JSONObject jsonObject) {
        super.onPostExecute(jsonObject);

        if(this.callBack != null)
            this.callBack.sync(jsonObject);// synchronize with MAIN LOOP THREAD
    }

    @Override
    protected void onCancelled() {
        super.onCancelled();

        if(this.callBack != null)
            this.callBack.cancel();

    }
}

用法示例:

public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         final Context _localContext = getContext();
         SomeAsyncTask.CallBack someCallBack = new SomeAsyncTask.CallBack() {

                @Override
                public void async(JSONObject jsonResult) {//async thread
                    //some async process, e.g. send data to server...
                }

                @Override
                public void sync(JSONObject jsonResult) {//sync thread
                    //get result...

                    //get some resource of Activity variable...
                    Resources resources = _localContext.getResources();
                }

                @Override
                public void progress(Integer... status) {//sync thread
                    //e.g. change status progress bar...
                }

                @Override
                public void cancel() {

                }

            };

            new SomeAsyncTask( someCallBack )
                                .execute("someParams0", "someParams1", "someParams2");

    }

你可以在几行中完成，只是在调用AsyncTask时覆盖onPostExecute。这里有一个例子:

new AasyncTask()
{
    @Override public void onPostExecute(String result)
    {
       // do whatever you want with result 
    }
}.execute(a.targetServer);

我希望这对你有帮助，编码快乐:)

我通过使用线程和处理程序/消息使它工作。 步骤如下: 声明进度对话框

ProgressDialog loadingdialog;

创建一个函数，在操作结束时关闭对话框。

   private Handler handler = new Handler() {
    @Override
    public void handleMessage(Message msg) {
        loadingdialog.dismiss();

    }
    };

编码你的执行细节:

 public void startUpload(String filepath) {
    loadingdialog = ProgressDialog.show(MainActivity.this, "Uploading", "Uploading Please Wait", true);
    final String _path = filepath;
    new Thread() {
        public void run() {
            try {
                UploadFile(_path, getHostName(), getPortNo());
                handler.sendEmptyMessage(0);

            } catch (Exception e) {
                Log.e("threadmessage", e.getMessage());
            }
        }
    }.start();
}