Question

I have created a dialog which can be called from anywhere by supplying a title and message as follows:

public void alertbox(String title, String mymessage)
{   new AlertDialog.Builder(this)
        .setTitle(title)
        .setMessage(mymessage)
        .setNeutralButton(android.R.string.cancel,
                new DialogInterface.OnClickListener() 
                {   public void onClick(DialogInterface dialog, int whichButton) {}
                })
        .show();
}

But I get a lockup when I try to dismiss the dialog from another method:

private void doCheck() {
    alertbox("status", getString(R.string.checking_license));
    mChecker.checkAccess(mLicenseCheckerCallback);

    alertbox.dismiss();
} 

It is the alertbox.dismiss(); statement that causes the crash. Any ideas how to properly do this?

Answer 1

It could be as simple as calling runOnUiThread:

runOnUiThread(new Runnable() {
    @Override
    public void run() {
        alertbox.dismiss();
    }
});

if you are on the wrong thread. Although with your additional details, the problem is more simple. To give away the punchline:

public AlertDialog alertbox(String title, String mymessage) {   
    return new AlertDialog.Builder(this)
        .setTitle(title)
        .setMessage(mymessage)
        .setNeutralButton(android.R.string.cancel,
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {}
            })
        .show();
}

and:

private void doCheck() {
    AlertDialog alert = alertbox("status", getString(R.string.checking_license));
    mChecker.checkAccess(mLicenseCheckerCallback);
    alert.dismiss();
}

Although you probably don’t want to both show and dismiss the dialog in the same method. Do you see how the above code is at least saving a reference to the dialog so that you can dismiss it later?