无法使用 DialogFragment 调用 MainActivity.super.onBackPressed()

Question

我有一个通用的 DialogFragment，我在 MainActivity 中将其用于多种不同的用途。其中之一是在用户按下后退按钮时显示退出应用程序的确认对话框。如果用户点击'yes'，我想调用MainActivity.super.onBackPressed()。问题是它不起作用，它只是关闭对话框。但是，如果我使用 finish() 而不是 MainActivity.super.onBackPressed() 它工作正常，但我知道最好的做法是使用 super.onBackPressed( ) 而不是 finish()。我试过只使用 super.onBackPressed() 或使用 getActivity()，没有解决。

感谢任何帮助 - 如何从 DialogFragment 正确调用 MainActivity.super.onBackPressed()？

这是我的代码：

public class ConfirmationDialog extends DialogFragment {
    // Do nothing by default
    private Runnable mConfirm = new Runnable() {
        @Override
        public void run() {
        }
    };
    // Do nothing by default
    private Runnable mCancel = new Runnable() {
        @Override
        public void run() {
        }
    };

    public void setArgs(String message, String yesButton, String noButton) {
        setArgs("", message, yesButton, noButton);
    }

    public void setArgs(String message, String yesButton) {
        setArgs("", message, yesButton, "");
    }

    public void setArgs(String title, String message, String yesButton, String noButton) {
        Bundle args = new Bundle();
        args.putString("message", message);
        args.putString("title", title);
        args.putString("yes_button", yesButton);
        args.putString("no_button", noButton);
        setArguments(args);
    }

    public void setConfirm(Runnable confirm) {
        mConfirm = confirm;
    }

    public void setCancel(Runnable cancel) {
        mCancel = cancel;
    }

    @Override
    public AlertDialog onCreateDialog(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Resources res = getActivity().getResources();
        String title = getArguments().getString("title");
        String message = getArguments().getString("message");
        String yesButton = getArguments().getString("yes_button");
        String noButton = getArguments().getString("no_button");
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity(), android.R.style.Theme_Material_Dialog_Alert);
        if (!noButton.equals(""))
            builder.setNegativeButton(noButton, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    mCancel.run();
                }
            });
        builder.setIcon(R.mipmap.my_launcher)
                .setTitle(title.equals("") ? res.getString(R.string.app_name) : title)
                .setMessage(message)
                .setPositiveButton(yesButton, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        mConfirm.run();
                    }
                });
        final AlertDialog dialog = builder.create();
        dialog.show();
        // If only positive button, center it.
        if (noButton.equals("")) {
            Button positiveButton = dialog.getButton(AlertDialog.BUTTON_POSITIVE);
            LinearLayout parent = (LinearLayout) positiveButton.getParent();
            LinearLayout.LayoutParams positiveButtonLL = (LinearLayout.LayoutParams) positiveButton.getLayoutParams();
            positiveButtonLL.width = ViewGroup.LayoutParams.MATCH_PARENT;
        }
        return dialog;
    }
}

在我的 MainActivity 中：

public void showDialogFragment(DialogFragment newFragment) {
    // DialogFragment.show() will take care of adding the fragment
    // in a transaction. We also want to remove any currently showing
    // dialog, so make our own transaction and take care of that here.
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    Fragment prev = getSupportFragmentManager().findFragmentByTag("dialog");
    if (prev != null) {
        ft.remove(prev);
    }
    // save transaction to the back stack
    ft.addToBackStack("dialog");
    newFragment.show(ft, "dialog");
}

@Override
public void onBackPressed() {
    ConfirmationDialog dialog = new ConfirmationDialog();
    dialog.setArgs(getResources().getString(R.string.exit_app_msg), getResources().getString(R.string.yes), getResources().getString(R.string.no));
    Runnable confirm = new Runnable() {
        @Override
        public void run() {
            **// finish();
            MainActivity.super.onBackPressed();**
        }
    };
    dialog.setConfirm(confirm);
    showDialogFragment(dialog);
}

Answer 1

一旦您的对话框显示，它就会获得焦点。然后你的后退键将关闭对话框，你的 activity 再次获得焦点，如果 activity 堆栈中只有一个 activity，再按一次后退键将关闭你的应用程序。这是正常流程。

如果您想退出您的应用：

android.os.Process.killProcess(android.os.Process.myPid());
System.exit(1);

或

// Recommended
Intent homeIntent = new Intent(Intent.ACTION_MAIN);
homeIntent.addCategory( Intent.CATEGORY_HOME );
homeIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);  
startActivity(homeIntent);

Answer 2

在您的 ConfirmationDialog

中试试这个

builder.setIcon(R.mipmap.my_launcher)
                .setTitle(title.equals("") ? res.getString(R.string.app_name) : title)
                .setMessage(message)
                .setPositiveButton(yesButton, new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.dismiss();
                        mConfirm.run();
                    }
                });

或在您的 activity

@Override
public void onBackPressed() {
    ConfirmationDialog dialog = new ConfirmationDialog();
    dialog.setArgs(getResources().getString(R.string.exit_app_msg), getResources().getString(R.string.yes), getResources().getString(R.string.no));
    Runnable confirm = new Runnable() {
        @Override
        public void run() {
            dialog.dismiss();
            MainActivity.super.onBackPressed();
        }
    };
    dialog.setConfirm(confirm);
    showDialogFragment(dialog);
}

无法使用 DialogFragment 调用 MainActivity.super.onBackPressed()

Can't invoke MainActivity.super.onBackPressed() using DialogFragment

android

android-fragments

android-dialogfragment