Category: xamarin

Xamarin – Did not find reference matching RestoreAssemblyResources AssemblyName metadata

Did you recently remove a package, but Visual Studio insists it’s there? Or did you readd it and VS seems to disagree? People on the Xamarin Forums tend to get good luck cleaning/rebuilding, and it miraculously starts working again for them. I wasn’t so fortunate and wasted a lot of time taking their word for it.


My exact error message

Error Did not find reference matching RestoreAssemblyResources AssemblyName metadata 'Google.MobileAds, Version=, Culture=neutral, PublicKeyToken=null' iosTests

If you’re like me, you’ve tried readding the package, modifying your packages.config file and still nothing is working

Here’s what you need to do:

  1. Locate your  .csproj file and open it in a text editor (Double clicking opens it in VS)
  2. Press CNTRL + F and search for the offending library
  3. Comment out the entry or delete it
  4. Build the project again (Since it’s Xamarin, it will take a lifetime to build) and it will hopefully work again!
  5. Success! 

I spent days trying to figure this out. When we as Xamarin developers run into issues like this, we need to share our solutions since there is little to no support from Xamarin. I hope all my fellow Xamarin developers will find this useful!

Displaying AdMob ads on iOS with Xamarin Forms!

All the tutorials on displaying ads on iOS are currently broken, as the package used to display ads has been removed.

There is a new package, however the usage example it gives is for an iOS dependent project. It will not work/compile for use in Xamarin Forms

The approach is the same however, You are rendering a View you declare in your portable project

Install the correct ad package, it should look like this in Nuget Package Manager


Here is the view I created in my Xamarin Forms project.

namespace CanadianClassifiedsAlerter
    public class AdMobView : View
        public AdMobView() { }

In my iOS project, I created a ViewRenderer.

[assembly: ExportRenderer(typeof(AdMobView), typeof(AdMobRenderer))]
namespace CanadianClassifiedsAlerter.iOS
    public class AdMobRenderer : Xamarin.Forms.Platform.iOS.ViewRenderer
        const string bannerId = "THISISWHEREMY_AD_IDGOES";

        BannerView adView;
        bool viewOnScreen = false;

        protected override void OnElementChanged(ElementChangedEventArgs<Xamarin.Forms.View> e)
            // Setup your BannerView, review AdSizeCons class for more Ad sizes. 
            adView = new BannerView(size: AdSizeCons.Banner, origin: new CGPoint(-10, 0))
                AdUnitID = bannerId,
                RootViewController = UIApplication.SharedApplication.Windows[0].RootViewController

            // Wire AdReceived event to know when the Ad is ready to be displayed
            adView.AdReceived += (object sender, EventArgs ea) => {
                viewOnScreen = true;



Now, after all is said and done to add it to my page, it’s this simple!


 mainLayout.Children.Add(new AdMobView
                WidthRequest = 320,
                HeightRequest = 50

Your end result should look like this


EDIT: Sample project files are here

Unused Canadian Classifieds Portable Project Files (Xamarin Forms).

I decided to use Xamarin.iOS instead for this project, so feel free to do whatever with those files.


EDIT: A user followed the advice from this article and got the following error…

“Foundation.MonoTouchException: Objective-C exception thrown. Name: NSInvalidArgumentException Reason: -[AppDelegate window]: unrecognized selector sent to instance 0x79aa9b10”

He override the Window with the following code and away it worked!

public override UIWindow Window {
return UIApplication.SharedApplication.KeyWindow;