应用程序在AsyncTask屏幕旋转时崩溃

有很多解决方案.一个简单的方法是使用所谓的保留"片段.在某些Google示例中使用了这种方法.保留片段没有UI，并且在方向更改时仍然存在.通常将其定义为您的活动的静态内部类，如下所示:

There are plenty of solutions to this. One simple one for you is to use what's known as a "Retain" fragment. This is an approach that is used in some of the Google samples. A retain fragment has no UI, and persists across orientation change. This is usually defined as a static inner class of your activity like so:

public static class RetainFragment extends Fragment {
    private static final String TAG = "RetainFragment";

    public RetainFragment() {}

    public static RetainFragment findOrCreateRetainFragment(FragmentManager fm) {
        RetainFragment fragment = (RetainFragment) fm.findFragmentByTag(TAG);
        if (fragment == null) {
            fragment = new RetainFragment();
        }
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setRetainInstance(true);
    }
}

然后，将AsyncTask放入RetainFragment内.调用onPostExecute时，您可以简单地使用该片段的getActivity()方法来获取其附加到的活动.

Then, put your AsyncTask inside of your RetainFragment. When onPostExecute is called, you can simply use the fragment's getActivity() method to get the Activity that it is attached to.

希望有帮助，让我知道是否仍然有些困惑！

Hope that helps, let me know if there is still some confusion!

编辑:此处是保留片段的Google样本

Here is a Google sample of a retain fragment

(根据评论)

public class A {

    // This class holds a reference to it's outer A instance. It can be
    // accessed using A.this.
    public class innerClassA {
        //...
    }

    // This class does not hold a reference to it's outer A instance.
    public static class innerClassB {
        //...
    }
}

在评论中，我还是写了完整的代码.对于任何有兴趣的人:

Edit 3: In the comments, I ended up writing the full code anyway. For anyone interested:

public class MyActivity extends Activity {

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

        Button b = (Button) findViewById(R.id.aaa);
        b.setOnClickListener(new View.OnClickListener() {
            @Override public void onClick(View v) {
                RetainFragment retainFragment =
                        RetainFragment.findOrCreateRetainFragment(getFragmentManager());
                retainFragment.loadAsync();
            }
        });
    }

    private void handleResponse(String response) {
        // do something with the response...
    }

    public static class RetainFragment extends Fragment {
        private static final String TAG = "RetainFragment";

        public RetainFragment() {
        }

        public static RetainFragment findOrCreateRetainFragment(FragmentManager fm) {
            RetainFragment fragment = (RetainFragment) fm.findFragmentByTag(TAG);
            if (fragment == null) {
                fragment = new RetainFragment();
                fm.beginTransaction().add(fragment, TAG).commit();
            }
            return fragment;
        }

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setRetainInstance(true);
        }

        private void loadAsync() {
            new AsyncTask<Void, Void, String>() {
                @Override protected String doInBackground(Void... params) {
                    // Do some work...
                    return null;
                }

                @Override protected void onPostExecute(String response) {
                    MyActivity myActivity = (MyActivity)getActivity();
                    if (myActivity != null) {
                        myActivity.handleResponse(response);
                    }
                }
            }.execute();
        }
    }
}