Question

I try to create a UIBarButtonItem with a custom view for a Toolbar. The view itself is displayed well, but when i click the BarButton, no action occurs. It looks like the touch event is not forwarded from the view to the UIBarButtonItem instance. I have checked the responder chain and i think it looks good. I have also searched the internet and checked the Apple documentation, but can’t find any hint for my problem.

Here is my code:

   g__objWeatherButton = new UIBarButtonItem[1];

   UIView l__objCustomView = g__objWeatherDisplay.InfoBarButton; // Returns a reference to my custom view

   UIBarButtonItem l__objButton = new UIBarButtonItem(l__objCustomView);

   l__objButton.Clicked += delegate {this.WeatherButtonEvent();}; // my action handler
   l__objButton.Width = 200;
   l__objButton.Enabled = true;

   g__objWeatherButton[0] = l__objButton;

   this.Items = g__objWeatherButton; // "this" is my UIToolbar object

Can someone give me a hint where the problem is? Or a working code sample (in c# please – have found some examples in Objective-C, but apparently overlooked the crucial trick 😉

Answer 1

No special trick. When you want to add a custom view to a toolbar or navigation bar, you should subscribe (and respond) to that view’s events. So instead of using a UIView to hold your image, create a UIButton with UIButtonType.Custom and subscribe to that button’s TouchUpInside event.

You then initialize it like you do with the UIView:

UIButton l__objCustomUIButton = UIButton.FromType(UIButtonType.Custom);
//l__objCustomUIButton.SetImage(UIImage.FromFile("your button image"), UIControlState.Normal);
l__objCustomUIButton.TouchUpInside += delegate { this.WeatherButtonEvent(); };
UIBarButtonItem l__objButton = new UIBarButtonItem(l__objCustomUIButton);

Just make sure you declare the button in the class scope.