UIButtonConfiguration problem updating UIButton

Question

I have a Xamarin.iOS app that uses the new UIButtonConfiguration API for styling buttons. I have a problem with updating the button fields in code, such as color and title. I'm using VS Mac 17.5, Xcode 14.2, Xamarin.iOS 16.2.

I've tried the below methods to update the button; neither of the titles and neither of the colors are applied. What could be the problem?

public partial class ViewController : UIViewController
{
    public ViewController(IntPtr handle) : base(handle) { }

    public override void ViewDidLoad ()
    {
        base.ViewDidLoad ();

        this.MyButton.ConfigurationUpdateHandler += this.UpdateHandler;
        this.MyButton.TouchUpInside += (s, a) =>
        {
            this.MyButton.Configuration.Title = "test 1";
            this.MyButton.Configuration.BaseForegroundColor = UIColor.Red;
            this.MyButton.SetNeedsUpdateConfiguration();
        };
    }

    private void UpdateHandler(UIButton button)
    {
        button.Configuration.Title = "test 2";
        button.Configuration.BaseForegroundColor = UIColor.Green;
    }
}

Answer 1

Hello,

ConfigurationUpdateHandler is to respond changes to the button’s state, the button's state is Normal, it doesn't change after you click the button (and you didn't set different config for different button state). Calling SetNeedsUpdateConfiguration method will make the system call updateConfiguration. The system calls this method automatically when the button’s state changes. Please see updateConfiguration | Apple Developer Documentation

If you want to change the configuration when you click the button, you can refer to the following code:

public override void ViewDidLoad ()
        {
            base.ViewDidLoad ();

          this.MyButton.Tag = 1;//set tag for testing
           this.MyButton.ConfigurationUpdateHandler += this.UpdateHandler;

           this.MyButton.TouchUpInside += (s, a) =>
            {
                MyButton.Tag = MyButton.Tag ==1?0:1;// change tag when you click the button
            };
        }
        private void UpdateHandler(UIButton button)
        {
            var config = UIButtonConfiguration.PlainButtonConfiguration;
            config.Title = "test1";
            config.BaseForegroundColor = UIColor.Green;
           /* it's recommended to change the config according to the state*/
            //switch (button.State)
            //{
            //    case UIControlState.Normal:
            //        config.Title = "Normal"; //or"test1"
            //        config.BaseForegroundColor = UIColor.Purple;
            //        break;
            //    case UIControlState.Selected:
            //        config.Title = "Selected";
            //        config.BaseForegroundColor = UIColor.Yellow;
            //        break;
            //    case UIControlState.Disabled:
            //        config.Title = "Disabled";
            //        config.BaseForegroundColor = UIColor.LightGray;
            //        break;
            //...and other states
            //    default:
            //        config.Title = "test1";
            //        config.BaseForegroundColor = UIColor.Green;
            //        break;
            //}

           if (button.Tag == 1)
            {
                config.Title = "test2";
                config.BaseForegroundColor = UIColor.Red;
            }
            button.Configuration = config;

       }

Best Regards,

Wenyan Zhang

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