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();
}

这个答案可能晚了，但我想提到一些事情，当你的活动依赖于AsyncTask。这将帮助您防止崩溃和内存管理。正如上面已经提到的，我们也称它们为回调。它们将作为一个通知器工作，但永远不会发送活动的强引用或接口总是使用弱引用在这些情况下。

请参考下面的截图，以了解如何导致问题。

正如你所看到的，如果我们用一个强引用启动AsyncTask，那么在我们获得数据之前，并不能保证我们的Activity/Fragment将是活的，所以在这些情况下使用WeakReference会更好，这也将有助于内存管理，因为我们永远不会持有我们的Activity的强引用，那么它将有资格在它扭曲后进行垃圾收集。

查看下面的代码片段，了解如何使用强大的WeakReference -

java接口，将作为一个通知器工作。

public interface MyTaskInformer {

    void onTaskDone(String output);

}

MySmallAsyncTask.java AsyncTask做长时间运行的任务，这将使用WeakReference。

public class MySmallAsyncTask extends AsyncTask<String, Void, String> {

    // ***** Hold weak reference *****
    private WeakReference<MyTaskInformer> mCallBack;

    public MySmallAsyncTask(MyTaskInformer callback) {
        this.mCallBack = new WeakReference<>(callback);
    }

    @Override
    protected String doInBackground(String... params) {

        // Here do whatever your task is like reading/writing file
        // or read data from your server or any other heavy task

        // Let us suppose here you get response, just return it
        final String output = "Any out, mine is just demo output";

        // Return it from here to post execute
        return output;
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);

        // Here you can't guarantee that Activity/Fragment is alive who started this AsyncTask

        // Make sure your caller is active

        final MyTaskInformer callBack = mCallBack.get();

        if(callBack != null) {
            callBack.onTaskDone(s);
        }
    }
}

这个类用于在这个类上启动我的AsyncTask实现接口，并覆盖这个强制方法。

public class MainActivity extends Activity implements MyTaskInformer {

    private TextView mMyTextView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mMyTextView = (TextView) findViewById(R.id.tv_text_view);

        // Start your AsyncTask and pass reference of MyTaskInformer in constructor
        new MySmallAsyncTask(this).execute();
    }

    @Override
    public void onTaskDone(String output) {

        // Here you will receive output only if your Activity is alive.
        // no need to add checks like if(!isFinishing())

        mMyTextView.setText(output);
    }
}

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");

    }

您需要使用“协议”将数据委托或提供给AsynTask。

委托和数据源

委托是一个对象，当另一个对象在程序中遇到事件时，它代表另一个对象或与另一个对象协调行动。(苹果定义)

协议是定义一些方法来委托一些行为的接口。

这是一个完整的例子!!

我觉得下面的方法很简单。

我已经声明了一个回调接口

public interface AsyncResponse {
    void processFinish(Object output);
}

然后创建异步任务来响应所有类型的并行请求

 public class MyAsyncTask extends AsyncTask<Object, Object, Object> {

    public AsyncResponse delegate = null;//Call back interface

    public MyAsyncTask(AsyncResponse asyncResponse) {
        delegate = asyncResponse;//Assigning call back interfacethrough constructor
    }

    @Override
    protected Object doInBackground(Object... params) {

      //My Background tasks are written here

      return {resutl Object}

    }

    @Override
    protected void onPostExecute(Object result) {
        delegate.processFinish(result);
    }

}

然后在活动类中单击按钮时调用异步任务。

public class MainActivity extends Activity{

    @Override
    public void onCreate(Bundle savedInstanceState) {

    Button mbtnPress = (Button) findViewById(R.id.btnPress);

    mbtnPress.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                MyAsyncTask asyncTask =new MyAsyncTask(new AsyncResponse() {

                    @Override
                    public void processFinish(Object output) {
                        Log.d("Response From Asynchronous task:", (String) output);

                        mbtnPress.setText((String) output);
                   }
                });

                asyncTask.execute(new Object[] { "Your request to aynchronous task class is giving here.." });


            }
        });

    }



}

谢谢

容易:

Create interface class, where String output is optional, or can be whatever variables you want to return. public interface AsyncResponse { void processFinish(String output); } Go to your AsyncTask class, and declare interface AsyncResponse as a field : public class MyAsyncTask extends AsyncTask<Void, Void, String> { public AsyncResponse delegate = null; @Override protected void onPostExecute(String result) { delegate.processFinish(result); } } In your main Activity you need to implements interface AsyncResponse. public class MainActivity implements AsyncResponse{ MyAsyncTask asyncTask =new MyAsyncTask(); @Override public void onCreate(Bundle savedInstanceState) { //this to set delegate/listener back to this class asyncTask.delegate = this; //execute the async task asyncTask.execute(); } //this override the implemented method from asyncTask @Override void processFinish(String output){ //Here you will receive the result fired from async class //of onPostExecute(result) method. } }

更新

我不知道这是你们很多人的最爱。这是一个简单方便的界面使用方法。

仍然使用相同的界面。供参考，你可以把它合并到AsyncTask类中。

在AsyncTask类中:

public class MyAsyncTask extends AsyncTask<Void, Void, String> {

  // you may separate this or combined to caller class.
  public interface AsyncResponse {
        void processFinish(String output);
  }

  public AsyncResponse delegate = null;

    public MyAsyncTask(AsyncResponse delegate){
        this.delegate = delegate;
    }

    @Override
    protected void onPostExecute(String result) {
      delegate.processFinish(result);
    }
}

在你的活动课上做这个吗

public class MainActivity extends Activity {
  
   MyAsyncTask asyncTask = new MyAsyncTask(new AsyncResponse(){
    
     @Override
     void processFinish(String output){
     //Here you will receive the result fired from async class 
     //of onPostExecute(result) method.
     }
  }).execute();

 }

或者，再次在Activity上实现接口

public class MainActivity extends Activity 
    implements AsyncResponse{
      
    @Override
    public void onCreate(Bundle savedInstanceState) {

        //execute the async task 
        new MyAsyncTask(this).execute();
    }
      
    //this override the implemented method from AsyncResponse
    @Override
    void processFinish(String output){
        //Here you will receive the result fired from async class 
        //of onPostExecute(result) method.
    }
}

正如你可以看到上面的两个解决方案，第一个和第三个，它需要创建方法processFinish，另一个，方法在调用者参数中。第三种方法更加简洁，因为没有嵌套的匿名类。

提示:将String输出、String响应和String结果更改为不同的匹配类型，以便获得不同的对象。