从一种方法调用时，Android AlertDialog 不会显示，但会从同一活动中的另一种方法显示。 为什么？

Question

I am in an activity and I am trying to display an alert dialog. The code is this:

AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("xx");
        builder.setPositiveButton(R.string.delete, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                built.dismiss();
            }
        });
        builder.setNegativeButton(R.string.giveup, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                built.dismiss();
            }
        });
        builder.setCancelable(true);
        built = builder.create();
        built.show();

The thing is, the same code is called in two different places in the activity and one works while the other doesn't! I don't understand because they are literally the same...

There are questions like this in this site and I tried most of them. I changed the this in the parameter to the activity name, I set a position, I put show() method, etc... I do not know how to proceed

And I put breakpoints in both of the places. The working one goes smoothly. But when it does not get displayed, the breakpoint crashes at 'builder.create()'. It doesn't go further than this (it doesnt see the next breakpoint which is built.show). It says "frames are not available"

Answer 1

I found it. Just putting it here in case someone needs it. I found it from here: Listener method (interface in Service) in my Activity doesn't want to display a simple message

The problem was that, I was calling the "not-working" one from an emitter.listener, thus it was not working on the correct thread. We need this to work on UI thread. When I added this:

runOnUiThread(new Runnable(){
        public void run(){
           showAlertDialog();
        }
    });

It worked!