Android: How to override onBackPressed() in AlertDialog?

问题

I have an AlertDialog dlgDetails which is shown from another AlertDialog dlgMenu. I would like to be able to show dlgMenu again if the user presses the back button in dlgDetails and simply exit the dialog if he presses outside the dialog.

I think the best way to do this is to override onBackPressed for dlgDetails, but I am not sure how to do that since AlertDialogs must be created indirectly using the Builder.

I am trying to create a derived AlertDialog (public class AlertDialogDetails extends AlertDialog { ...} ) but then I guess I must also extend AlertDialog.Builder in that class to return an AlertDialogDetails, but isn't there a simpler way? And if not, how would you go about overriding the Builder?

回答1:

I finally added a key listener to my dialog to listen to the Back key. Not as elegant as overriding onBackPressed() but it works. Here is the code:

dlgDetails = new AlertDialog.Builder(this)
    .setOnKeyListener(new DialogInterface.OnKeyListener() {
        @Override
        public boolean onKey (DialogInterface dialog, int keyCode, KeyEvent event) {
            if (keyCode == KeyEvent.KEYCODE_BACK && 
                event.getAction() == KeyEvent.ACTION_UP && 
                !event.isCanceled()) {
                dialog.cancel();
                showDialog(DIALOG_MENU);
                return true;
            }
            return false;
        }
    })
    //(Rest of the .stuff ...)

回答2:

Found a shorter solution :) try this:

         accountDialog = builder.create();

        accountDialog.setOnCancelListener(new OnCancelListener() {

            @Override
            public void onCancel(DialogInterface dialog) {
                dialog.dismiss();
                activity.finish();

            }
        });

回答3:

This handles both the BACK button and the click OUTSIDE the dialog:

yourBuilder.setOnCancelListener(new OnCancelListener() {
    @Override
    public void onCancel(DialogInterface dialog) {
        dialog.cancel();
        // do your stuff...
    }
});

dialog.cancel() is the key: with dialog.dismiss() this would handle only the click outside of the dialog, as answered above.

回答4:

I created a new function within the java class and made a call to that function from the onClick method of the dialog Builder.

public class Filename extends Activity(){

@Override
onCreate(){
 //your stuff
 //some button click launches Alertdialog
}

public void myCustomDialog(){
 AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
 //other details for builder
      alertDialogBuilder.setNegativeButton("BACK",
            new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
                         dialod.dismiss;
                         myCustomBack();
                    }
      });

 AlertDialog alertDialog = alertDialogBuilder.create();
 alertDialog.setCanceledOnTouchOutside(true);
 alertDialog.show();
}

public void myCustomBack(){
  if(condition1){
    super.onBackPressed();
  }
  if(condition 2){
    //do  stuff here
  }
}

@Override
public void onBackPressed(){
  //handle case here
  if (condition A)
    //Do this
  else 
    //Do that
}

}

来源：https://stackoverflow.com/questions/7801971/android-how-to-override-onbackpressed-in-alertdialog