Question

我有一个托管片段的活动。在那片段中，我打开一个DialogFragment。

在片段中，我调用此函数来显示对话框。请注意，在显示对话框之前，我设置了DialogFragment中定义的接口。

private void showRatingDialog(){

        if (getActivity() != null) return;

        MyRatingDialog ratingDialog = new MyRatingDialog();
        ratingDialog.setOnRatingDialog(new MyRatingDialog.OnRatingDialog() {
            // some code
        });

        ratingDialog.show(getActivity().getSupportFragmentManager(), MyRatingDialog.TAG);        

}

我的MyRatingDialog课程：

public class MyRatingDialog extends DialogFragment{

    private OnRatingDialog onRatingDialog;

    public interface OnRatingDialog{
        void onSubmitRating(int rateSelected);
        void onCancelRating();
    }

    public void setOnRatingDialog(OnRatingDialog onRatingDialog) {
        this.onRatingDialog = onRatingDialog;
    }


    @NonNull
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {

        View layout = getActivity().getLayoutInflater().inflate(R.layout.dialog_rating, null, false);

        alertDialog = new AlertDialog.Builder(getActivity()).setView(layout).create();
        alertDialog.setCancelable(false);

        ratingStarComponent = (RatingStarComponent)layout.findViewById(R.id.rating_star_component);
        ratingStarComponent.setOnRateListener(new RatingStarComponent.OnRateListener() {
            @Override
            public void onRateClickListener(int starRate) {
                rate = starRate;
            }
        });

        Button rateButton = (Button)layout.findViewById(R.id.rate);
        rateButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (onRatingDialog!=null) { // this is null after a configuration change
                    onRatingDialog.onSubmitRating(rate, optionsSelected, commentsEditText.getText().toString());
                    alertDialog.dismiss();
                }
            }
        });

        ImageView closeButton = (ImageView)layout.findViewById(R.id.close);
        closeButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                alertDialog.dismiss();
            }
        });

        return alertDialog;


    }

    @Override
    public void onDismiss(DialogInterface dialog) {
        super.onDismiss(dialog);

        onRatingDialog.onCancelRating();

    }

}

问题是在像屏幕旋转或任何其他configurationChange之类的configurationChange之后，onRatingDialog接口为null。我的问题是在configurationChange之后保存对onRatingDialog接口的引用的最佳方法/最佳实践是什么？我不想让托管的Activity实现接口，因为我认为对对话框的访问更复杂。通过执行setRetainInstance（true），对话框在configurationChange之后关闭，那么如何保持对话框可见，保持对接口的引用。

感谢。

Answer 1

结帐fragments doc.

在页面上找到以下代码来实现一个监听器，你的Activity必须实现你在对话框中创建的监听器。然后将从dialogFragment通知Activity并从Activity中通知相关片段。

public static class FragmentA extends ListFragment {
OnArticleSelectedListener mListener;
...
@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);
    try {
        mListener = (OnArticleSelectedListener) activity;
    } catch (ClassCastException e) {
        throw new ClassCastException(activity.toString() + " must implement OnArticleSelectedListener");
    }
}
...

您还可以下载示例项目here

在configurationChange之后保存对DialogFragment中的接口回调的引用

1 个答案: