如何禁用第二个底部对话框的后退按钮？

Question

我正在创建MainActivity。此活动有一个按钮可打开片段，而该片段有一个按钮可打开底部工作表对话框。

当我在Fragment上时，可以按Back按钮返回MainActivity。但是，当我已经打开了“底部对话框”时，我想禁用“后退”按钮，以便在显示“底部对话框”时用户无法按“后退”按钮。那我该怎么做呢？谢谢。

MainActivity

public class MainActivity extends SdwBaseActivity {

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

public void startAction(View view){
    LoadCashTutorialScreen loadCashTutorialScreen = LoadCashTutorialScreen.newInstance();
 getSupportFragmentManager().beginTransaction().replace(R.id.container, loadCashTutorialScreen, "LoadCashTutorialScreen").addToBackStack("LoadCashTutorialScreen").commit();
}

@Override
public void onBackPressed(){
      super.onBackPressed()
      //do something so that the back button is disable when the Bottom Dialog is showing
}
}

片段：

public class LoadCashTutorialScreen extends Fragment{
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = initView(inflater, container, R.layout.load_cash_tutorial_screen);
        Button startDialog = view.findViewById(R.id.dialogButton);
        startDialog.setOnClickListener(view1 -> {
            MyBottomDialog dialog = new MyBottomDialog();
            dialog.show(activity.getSupportFragmentManager(), "BottomDialog");
        });

        return view;
    }
}

对话框：

public class MyBottomDialog extends BottomSheetDialogFragment {
    @Override
    public void setupDialog(@NonNull Dialog dialog, int style) {
        super.setupDialog(dialog, style);
        View contentView = View.inflate(getContext(), R.layout.load_cash_bottom_dialog, null);
        dialog.setContentView(contentView);
        dialog.setCanceledOnTouchOutside(false);
        dialog.setCancelable(false);
    }
}

注意：我以前在onBackPressed（）上编写了一些方法来防止对话框消失，但是，按Back时对话框总是消失。调试后，我意识到显示底部对话框时未达到onBackPressed（）。我不知道为什么。

Answer 1

由于底页是Fragment，因此您必须以其他方式收听。使用这个：

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    // ...
    setupBackPressListener()
}

private fun setupBackPressListener() {
    this.view?.isFocusableInTouchMode = true
    this.view?.requestFocus()
    this.view?.setOnKeyListener { _, keyCode, _ ->
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            // Do what you want to do on back press
            true
        } else
            false
    }
}