java - 如何在调用 stopService 方法后停止服务中的线程？在安卓中

Question

使用服务上传图像

在我的应用程序中，我正在将图像上传到服务器，我使用后台服务来执行此操作，上传是在服务中的另一个线程中执行的。我已经读到，服务在 UI 线程上运行，服务中的线程是另一个进程，我需要的是，我想在单击按钮调用 stopService 时取消上传。所以我想杀死该线程，我尝试了这段代码，但它无法正常工作。有人可以帮忙吗？请吗？

    private void uploadPhoto(Bitmap   bitmap) {
    //in this method you upload the photo to the server: omitted for brevity
    Log.e("Method", "uploadPhoto called");
    final Bitmap bit = bitmap;
    flag=true;

           uploadthread = new Thread(new Runnable() {

                    @Override
                    public void run() {

                        Log.e("While", "Inside while loop");
                        try {

                            while (true) {

                                if (flag) {
                                    Log.e("IF", "Inside IF condition"+flag);
                                     return;

                                    //uploadthread.destroy();
                                }
                                handler.sendEmptyMessage(0);
                                // t.sleep(5000);
                                // Toast.makeText(getApplicationContext(), "Horas",
                                // Toast.LENGTH_LONG).show();
                                Log.e("Upload", "Upload Started inside Thread");

                                HttpClient httpClient = new DefaultHttpClient();
                                HttpContext localContext = new BasicHttpContext();
                                HttpPost httpPost = new HttpPost(Config.FILE_UPLOAD_URL);

                                MultipartEntity entity = new MultipartEntity(HttpMultipartMode.BROWSER_COMPATIBLE);


                                ByteArrayOutputStream bos = new ByteArrayOutputStream();
                                bit.compress(Bitmap.CompressFormat.JPEG, 100, bos);
                                byte[] data = bos.toByteArray();


                                entity.addPart("uploaded_file", new ByteArrayBody(data,
                                        "myImage.jpg"));

                                httpPost.setEntity(entity);

                                HttpResponse response = httpClient.execute(httpPost,
                                        localContext);
                                BufferedReader reader = new BufferedReader(
                                        new InputStreamReader(
                                                response.getEntity().getContent(), "UTF-8"));

                                StringBuilder builder = new StringBuilder();
                                String aux = "";

                                while ((aux = reader.readLine()) != null) {
                                    builder.append(aux);
                                }

                                String sResponse = builder.toString();
                                handler.sendEmptyMessage(0);

                            }
                            }
                            catch(Exception e){
                                e.printStackTrace();
                            }


                          //  stopSelf();
                        }


                });
                uploadthread.start();
              }

onDestroy方法

 @Override
public void onDestroy() {
 try {
        handler.removeCallbacks(uploadthread);
    }
    catch(Exception e)
    {
        e.printStackTrace();
    }
    EndNotification();
    flag = false;
    Log.e("Service", "Service Destroyed");
    Toast.makeText(this, "Service Destroyed", Toast.LENGTH_LONG).show();
    super.onDestroy();


}

Answer 1

首先，不要使用线程，使用异步任务，这是处理网络和数据库调用等后台进程的最佳方式。

要从 UI 取消任何级别的异步任务，您可以使用 cancel() 方法。

Here是 AsyncTask 的示例和 API。