Getting Error: CS0234 The type or namespace name 'Android' does not exist in the namespace 'Xamarin.Forms.Platform' (are you missing an assembly reference?)

Question

i have a Xamarin App (UWP & Android). The UWP still works, but after upgrading Nuget pacjkages i get the errors shown below. All the errors are in the MainActivity.cs File.

Am I missing a Nuget Package or other reference? If so, which?

Error CS0234: The type or namespace name 'Android' does not exist in the namespace 'Xamarin.Forms.Platform' (are you missing an assembly reference?) in the MainActivity.cs file.

Error CS0234 The type or namespace name 'Platform' does not exist in the namespace 'Xamarin.Essentials' (are you missing an assembly reference?)

Error CS0234 The type or namespace name 'Forms' does not exist in the namespace 'Xamarin.Forms' (are you missing an assembly reference?)

also some like: Error CS1061 'MainActivity' does not contain a definition for 'Assets' and no accessible extension method 'Assets' accepting a first argument of type 'MainActivity' could be found (are you missing a using directive or an assembly reference?)

here are also additional errors (CS0103) of methods that don't exist, such as GetSystemService, NotificationService, StartActivity, AudoService, TabLayoutResource, ToolbarResource, LoadApplication

Error CS1061 'MainActivity' does not contain a definition for 'Assets' and no accessible extension method 'Assets' accepting a first argument of type 'MainActivity' could be found (are you missing a using directive or an assembly reference?)

Answer 1

Hallo

I had same problem after Visual Studio updated to 17.8

My workaround which fix problem on my computer: 

I JUST PUT PREVIOUS *.csproj (before update VS/Nuget update) Android.csproj and MAIN csproj back to project
I don't know why, but it's work :-)


Android.csproj (after update)
    <PackageReference Include="Xamarin.Essentials">
      <Version>1.8.0</Version>
    </PackageReference>
    <PackageReference Include="Xamarin.Forms">
      <Version>5.0.0.2622</Version>
    </PackageReference>

Android.csproj (before update)
    <PackageReference Include="Xamarin.Forms" Version="5.0.0.2196" />
    <PackageReference Include="Xamarin.Essentials" Version="1.7.0" />

MAIN csproj (after update)
    <PackageReference Include="Xamarin.Essentials" Version="1.8.0" />
    <PackageReference Include="Xamarin.Forms" Version="5.0.0.2622" />

MAIN csproj (before update)
    <PackageReference Include="Xamarin.Forms" Version="5.0.0.2196" />  
    <PackageReference Include="Xamarin.Essentials" Version="1.7.0" />

Answer 2

i think the step that i did was manage NuGets and updated some of them. i did not make any code changes

so far i have

• deleted bin and obj folders (also cleaned the builds)
• repaired and updated VS 2022
• restored a previous version of the code from GIT

Answer 3

I had something similar, all the cleanings didn't help.

You need to see which assembly references you are relying on and make sure it is not broken (yellow mark) if they are broken add them manually for the correct project. Check the path and the Copy Local property set to True for every assembly except system assemblies.

But my main problem was the assembly that is outside the solution is built in the Target framework which is different and higher than the Target framework on a problematic solution. I changed it to be like the higher target version one and "poof" the errors disappeared like magic. :)