iphone dev-blog

You don’t even need to subclass UITextField with this dirty trick. All you do is save the password somewhere else, and set it to a mask of *’s when you finish editing. All you need is a global NSString called password and a few IBActions.

- (NSString *)username { return [userField text]; }
- (NSString *)password { return password; }

- (IBAction)editingEnded:(id)sender {
        NSString *oldtext = passField.text;
        int len = (oldtext) ? [oldtext length] : 0;
        int i;
        NSString *mask = @"";
        for (i = 0; i < len; i++) {
                mask = [mask stringByAppendingString:@"*"];
        }
        if (password) { [password release]; password = nil; }
        password = oldtext;
        [password retain];
        passField.text = mask;
}

- (IBAction)editingBegan:(id)sender {
        passField.text = password;
}

Cool, no? You don’t even have to draw anything.
There’s probably more elegant approaches, ones that replace the chars as you’re typing, etc. But this works for me

Joe