How do you disable a button inside of an AlertDialog?

问题

I am trying to write an AlertDialog with 3 buttons. I want the middle, Neutral Button to be disabled if a certain condition is not met.

Code

int playerint = settings.getPlayerInt();
int monsterint = settings.getMonsterInt();



        AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
        alertbox.setMessage("You have Encountered a Monster");

        alertbox.setPositiveButton("Fight!",
                new DialogInterface.OnClickListener() {

                    // do something when the button is clicked
                    public void onClick(DialogInterface arg0, int arg1) {
                        createMonster();
                        fight();

                    }
                });

        alertbox.setNeutralButton("Try to Outwit",
                new DialogInterface.OnClickListener() {

                    // do something when the button is clicked
                    public void onClick(DialogInterface arg0, int arg1) {
                        // This should not be static
//                      createTrivia();
                        trivia();

                    }
                });

        // Return to Last Saved CheckPoint
        alertbox.setNegativeButton("Run Away!",
                new DialogInterface.OnClickListener() {

                    // do something when the button is clicked
                    public void onClick(DialogInterface arg0, int arg1) {
                        runAway();
                    }
                });

        // show the alert box
        alertbox.show();

// Intellect Check

Button button = ((AlertDialog) alertbox).getButton(AlertDialog.BUTTON_NEUTRAL);

        if(monsterint > playerint) {


            button.setEnabled(false);

        }
    }

The line:

Button button = ((AlertDialog) alertbox).getButton(AlertDialog.BUTTON_NEUTRAL);

Gives error:

Cannot cast from AlertDialog.Builder to AlertDialog

How do I fix this?

回答1:

You can't call getButton() on the AlertDialog.Builder. It has to be called on the resulting AlertDialog after creation. In other words

AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
//...All your code to set up the buttons initially

AlertDialog dialog = alertbox.create();
Button button = dialog.getButton(AlertDialog.BUTTON_NEUTRAL);
if(monsterint > playerint) {
    button.setEnabled(false);
}

The builder is just a class to make constructing the dialog easier...it isn't the actual dialog itself.

HTH

回答2:

Better solution in my opinion:

AlertDialog.Builder builder = new AlertDialog.Builder(context); 
builder.setPositiveButton("Positive", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int whichButton) {
        // some code
    }
});
AlertDialog alertDialog = builder.create();
alertDialog.setOnShowListener(new DialogInterface.OnShowListener() {
            @Override
            public void onShow(DialogInterface dialog) {
                if(**some condition**)
                {
                    Button button = alertDialog.getButton(AlertDialog.BUTTON_POSITIVE);
                    if (button != null) {
                        button.setEnabled(false);
                    }
                }
            }
        });

回答3:

The trick is that you need to use the AlertDialog object retuned by AlertDialog.Builder.show() method. No need to call AlertDialog.Builder.create().

Example:

        AlertDialog dialog = alertbox.show();
        if(monsterint > playerint) {
            Button button = dialog.getButton(AlertDialog.BUTTON_NEUTRAL);
            button.setEnabled(false);
        }

来源：https://stackoverflow.com/questions/7392321/how-do-you-disable-a-button-inside-of-an-alertdialog