Creating a custom image on UIToolbar in MonoTouch

Recently I had to create a custom button for UIToolbar. Specifically, in my case, it was not a button, but a separator. I was very surprised to find out that UIBarButtonItem does not have a height attribute. Turns out there is a workaround to set a customer hight for a UIBarButtonItem. This is what I did:

// Create a custom image of needed hight with a regular button
var customerImageButton = new UIButton (UIButtonType.Custom);
customerImageButton.SetBackgroundImage (UIImage.FromFile 
                   ("Images/separator.png"), UIControlState.Normal);
   
customerImageButton.Frame = new RectangleF (0, 0, 3, 46);

// Initialize new UIBarButtonItem from a custom view - new button
var customerBarButton = new UIBarButtonItem (customerImageButton);

// Make updates to the existing bar
var barButtonList = new List ();

// Update toolbar in xib/story board with custom items
for (var i =0; i< tlbrMainToolbar.Items.Length; i++)  
{  
  if (i == 4)    
  {
      // replace placeholder button with a custom separator
      // In my case it was button 4 
      barButtonList.Add(customerBarButton);   
  }    
  else   
  {   
      barButtonList.Add (tlbrMainToolbar.Items[i]);   
  } 
}

// Set the new button list for the toolbar 
tlbrMainToolbar.Items = barButtonList.ToArray();

Hope this saves someone time!

More orientation in iOS with MonoTouch

I ran into some interesting orientation distinctions with MonoTouch development. Luckily the good folks at Xamarin were very helpful on their forums.

 Regarding orientation, this is what I learned from Adam Kemp:

There are two kinds of orientation: device orientation UIDeviceOrientation and interface orientation UIInterfaceOrientation. Interface orientation tells you whether it's portrait, portrait upside down, landscape left, or landscape right. Device orientation has more spatial orientations like face up or face down (i.e., how is the user holding the device, rather than what does the screen look like). Device orientation is much more prone to changes even when the interface doesn't change at all (and sometimes the device doesn't know at all, hence the "unknown").

UIDevice.CurrentDevice.Orientation gives you the device orientation.

To get interface orientation you use UIApplication.SharedApplication.StatusBarOrientation.

You can also observe changes to the orientation by adding an observer like this:

   _interfaceNotificationHandle = 
         NSNotificationCenter.DefaultCenter.AddObserver(
            UIApplication.DidChangeStatusBarOrientationNotification, 
            HandleInterfaceOrientationDidChangeNotification); 

And don't forget to unregister (in this case I do it in Dispose(), but for a view you might want to register when the view is added to a window and unregister when it's removed):

public void Dispose() 
{ 
    if (!_disposed) 
    { 
        if (_interfaceNotificationHandle != null) 
        { 
            NSNotificationCenter.DefaultCenter
                .RemoveObserver(_interfaceNotificationHandle); 

            _interfaceNotificationHandle = null; 
        }
        
        _disposed = true; 
         
    } 
}