android - 静态异步任务进度条

Question

抱歉，如果这看起来是一个基本问题。我已经更新了 Android Studio 并注意到我的 AsyncTasks 上有一些内存泄漏警告说我应该将它们设为静态。我已将它们设为静态，但似乎无法在没有收到相同内存泄漏警告的情况下使 List、ProgressBar、ImageView 之类的东西正常工作。看来我怎么试都赢不了。我想我的问题是:

1. AsyncTasks 应该是静态的吗？官方文档并未将其设为静态，但我的 IDE 会发出警告说他们应该这样做。

2. 如果它们是静态的，我如何在静态 AsyncTask 中启动和停止 ProgressBar。

编辑

这仍然会抛出“This AsyncTask class should be static or leaks might occur”

private class DownloadCategoryTask extends AsyncTask<String, Integer, String> {

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

        Thread.currentThread().setPriority(Thread.MAX_PRIORITY);

        String url = Config.API_URL +
                "/Index.aspx?" +
                "type=3&" +
                "site_id=" + SITE_ID;

        String method = "GET";

        String array_name = "categories";

        Downloaded_category_array = Config.getJSONNew(url, method, array_name, context);

        return "";

    }

    protected void onPostExecute(String result) {

        if(isCancelled()){
            return;
        }

        getActivity().runOnUiThread(new Runnable() {
            @Override
            public void run() {
                //Update your UI here
                //showProgressBar();
            }
        });

        Populate_category_list();
    }
}

Answer 1

试试我发现的这个解决方案:

public class MainActivity extends AppCompatActivity {
   private ProgressBar progressBar;

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

      progressBar = findViewById(R.id.progress_bar);
   }

   public void startAsyncTask(View v) {
      ExampleAsyncTask task = new ExampleAsyncTask(this);
      task.execute(10);
   }

    private static class ExampleAsyncTask extends AsyncTask<Integer, Integer, String> {
       private WeakReference<MainActivity> activityWeakReference;

       ExampleAsyncTask(MainActivity activity) {
          activityWeakReference = new WeakReference<MainActivity>(activity);
       }

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

        MainActivity activity = activityWeakReference.get();
        if (activity == null || activity.isFinishing()) {
            return;
        }

        activity.progressBar.setVisibility(View.VISIBLE);
    }

    @Override
    protected String doInBackground(Integer... integers) {
        for (int i = 0; i < integers[0]; i++) {
            publishProgress((i * 100) / integers[0]);
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        return "Finished!";
     }
  }
}

引用:here