如何从静态ASyncTask中获取当前显示的活动？

public class MainActivity extends AppCompatActivity {
    private static MainActivity currentActivity;

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

        currentActivity = this;

        // 启动静态AsyncTask
        MyStaticAsyncTask myTask = new MyStaticAsyncTask();
        myTask.execute();
    }

    public static MainActivity getCurrentActivity() {
        return currentActivity;
    }

    private static class MyStaticAsyncTask extends AsyncTask<Void, Void, Void> {
        @Override
        protected Void doInBackground(Void... voids) {
            // 在后台执行任务
            // 可以通过MainActivity.getCurrentActivity()获取当前显示的活动
            MainActivity activity = MainActivity.getCurrentActivity();
            // 使用activity进行操作
            return null;
        }
    }
}