Issues on MAUI Project upgraded from Xamarin Forms Project

Question

Issues on MAUI Project upgraded from Xamarin Forms Project

Sreejith Sreenivasan 1,001

I have converted a Xamarin project to MAUI project using Upgrade Assistant as per this blog. First I upgraded solution, then I upgraded the android and ios projects. After that I build my solution but I get the below errors.

Severity Code Description Project File Line Suppression State

Error NETSDK1047 Assets file 'C:\Users\SREEJITH\source\repos\MAUIDemo\MAUIDemo\MAUIDemo.iOS\obj\project.assets.json' doesn't have a target for 'net6.0-ios/ios-arm64'. Ensure that restore has run and that you have included 'net6.0-ios' in the TargetFrameworks for your project. You may also need to include 'ios-arm64' in your project's RuntimeIdentifiers. MAUIDemo.iOS C:\Program Files\dotnet\sdk\7.0.306\Sdks\Microsoft.NET.Sdk\targets\Microsoft.PackageDependencyResolution.targets 266

Error CS0234 The type or namespace name 'Forms' does not exist in the namespace 'Xamarin' (are you missing an assembly reference?) MAUIDemo.Android (net6.0-android) C:\Users\SREEJITH\source\repos\MAUIDemo\MAUIDemo\MAUIDemo.Android\MainActivity.cs 11 Active

Error CS0234 The type or namespace name 'Content' does not exist in the namespace 'MAUIDemo.Android' (are you missing an assembly reference?) MAUIDemo.Android (net6.0-android) C:\Users\SREEJITH\source\repos\MAUIDemo\MAUIDemo\MAUIDemo.Android\MainActivity.cs 21 Active

Error CS0234 The type or namespace name 'Essentials' does not exist in the namespace 'Xamarin' (are you missing an assembly reference?) MAUIDemo.Android (net6.0-android) C:\Users\SREEJITH\source\repos\MAUIDemo\MAUIDemo\MAUIDemo.Android\MainActivity.cs 17 Active

Error CS0234 The type or namespace name 'Forms' does not exist in the namespace 'Xamarin' (are you missing an assembly reference?) MAUIDemo.Android (net6.0-android) C:\Users\SREEJITH\source\repos\MAUIDemo\MAUIDemo\MAUIDemo.Android\MainActivity.cs 18 Active

Error CS0103 The name 'LoadApplication' does not exist in the current context MAUIDemo.Android (net6.0-android) C:\Users\SREEJITH\source\repos\MAUIDemo\MAUIDemo\MAUIDemo.Android\MainActivity.cs 19 Active

Error CS0234 The type or namespace name 'Essentials' does not exist in the namespace 'Xamarin' (are you missing an assembly reference?) MAUIDemo.Android (net6.0-android) C:\Users\SREEJITH\source\repos\MAUIDemo\MAUIDemo\MAUIDemo.Android\MainActivity.cs 23 Active

Screenshot:

User's image

I have a few questions related to this:

I upgraded the solution, android and iOS projects. Is solution upgrade is enough or do we need to upgrade the android and iOS projects?
When I create a new MAUI project, I found there is a Platforms folder and on that I found Android and iOS sub folders. But when upgrade no such folders are created on my side, should I create it manually?
Below is the project structure of a MAUI project created. Like that do I need to create all the files and folders?

User's image

Anonymous

2023-08-07T06:42:46.73+00:00

Did you use .NET Upgrade Assistant extension or the command line? When you migrated, did you get some errors?

If you migrate successfully, you will not get these errors, Xamarin.Forms and Xamarin.Essentials NuGet packages and namespace will be removed automatically.

Now you can try to open your .csproj file, delete 'ios-arm64', and remove the Xamarin.Forms and Xamarin.Essentials namespace manually. If you can build and run it without any issue, if so you do not need to add these folders.

Sreejith Sreenivasan 1,001

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

I have used the upgrade assistant to upgrade the project to MAUI from Xamarin Forms and I didn't get any errors. Please check below screenshots:

Main Project:

Android Project:

iOS Project:

Xamarin.Forms and Xamarin.Essentials NuGet packages removed successfully, but in MainActivity the code are not removed.

From which .csproj file I need to remove the ios-arm64, from main project or ios project?

Main Project.csproj:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFrameworks>net6.0-android;net6.0-ios</TargetFrameworks>
    <UseMaui>True</UseMaui>
    <OutputType>Library</OutputType>
    <ImplicitUsings>enable</ImplicitUsings>
    <SingleProject>true</SingleProject>
  </PropertyGroup>
</Project>

iOS Project.csproj:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <EnableSGenConc>true</EnableSGenConc>
    <ProvisioningType>automatic</ProvisioningType>
    <TargetFrameworks>net6.0-ios</TargetFrameworks>
    <UseMaui>True</UseMaui>
    <AssemblyTitle>MAUIDemo.iOS</AssemblyTitle>
    <Product>MAUIDemo.iOS</Product>
    <Copyright>Copyright ©  2014</Copyright>
    <AssemblyVersion>1.0.0.0</AssemblyVersion>
    <FileVersion>1.0.0.0</FileVersion>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|iPhoneSimulator' ">
    <MtouchLink>None</MtouchLink>
    <MtouchDebug>true</MtouchDebug>
    <RuntimeIdentifiers>iossimulator-x64</RuntimeIdentifiers>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|iPhoneSimulator' ">
    <MtouchLink>None</MtouchLink>
    <RuntimeIdentifiers>iossimulator-x64</RuntimeIdentifiers>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|iPhone' ">
    <CodesignKey>iPhone Developer</CodesignKey>
    <MtouchDebug>true</MtouchDebug>
    <MtouchLink>None</MtouchLink>
    <MtouchInterpreter>-all</MtouchInterpreter>
    <RuntimeIdentifiers>ios-arm64</RuntimeIdentifiers>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|iPhone' ">
    <CodesignKey>iPhone Developer</CodesignKey>
    <RuntimeIdentifiers>ios-arm64</RuntimeIdentifiers>
  </PropertyGroup>
  <ItemGroup>
    <ProjectReference Include="..\MAUIDemo\MAUIDemo.csproj" />
  </ItemGroup>
</Project>

Could you please also answer the 3 questions I asked?

Anonymous

2023-08-08T08:43:31.6633333+00:00
I upgraded the solution, android and iOS projects. Is solution upgrade is enough or do we need to upgrade the android and iOS projects?

When I create a new MAUI project, I found there is a Platforms folder and on that I found Android and iOS sub folders. But when upgrade no such folders are created on my side, should I create it manually?

Below is the project structure of a MAUI project created. Like that do I need to create all the files and folders?

After migrating, if you can build and run your project normally, it is enough and no need to add other folders. If you have other needs in future development, you can add it as well.

However, if you still have Xamarin.Forms or Essentials nugget packages, it does not migrate successfully. You can check the second image; 19 files were skipped.
Sreejith Sreenivasan 1,001 Reputation points

2023-08-09T14:17:01.86+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

I upgraded the solution, android and iOS projects. Is solution upgrade is enough or do we need to upgrade the android and iOS projects?

Do we need to upgrade solution only or android and iOS projects?
Sreejith Sreenivasan 1,001 Reputation points

2023-08-09T15:39:42.4766667+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

Pending errors when I upgrade the project using upgrade assistant with .Net 6. Upgraded solution, android and ios.

Screenshot:

Pending errors when I upgrade the project using upgrade assistant with .Net 8. Upgraded solution, android and ios.

Always the solution upgrade is success without skipping any files. But android and ios upgradation skipping a lot of files. Please redirect me what mistake I am doing.
Anonymous

2023-08-10T02:07:04.5066667+00:00

Could you share a demo with us?
Sreejith Sreenivasan 1,001 Reputation points

2023-08-10T07:40:21.0066667+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

Here I have uploaded the demo for the migrated project using .Net 6 and Here I have uploaded the demo for the migrated project using .Net 8.
Anonymous

2023-08-11T09:12:50.3066667+00:00

I downloaded your .net 6 project, please refer this Bootstrap your migrated app document and edit your files. I strongly recommended this migrated video from James, here are lots of error and fixed way in it.
Sreejith Sreenivasan 1,001 Reputation points

2023-08-11T14:39:05.2666667+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

I will try this and update you soon.
Sreejith Sreenivasan 1,001 Reputation points

2023-08-11T14:46:24.7233333+00:00
@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

I have edited the files as per document and all the errors are gone.

Also I have commented the OnRequestPermissionsResult in the MainActivity. Is this make any problem or is there a way to fix it without commenting?

public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults) { Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults); base.OnRequestPermissionsResult(requestCode, permissions, grantResults); }

But I can't run the app on my device bacause the device is not listing in debug section.

But the device is available for all the other projects. Anything else to do to fix this issue?

Accepted answer

0 additional answers

Your answer

Anonymous

2023-08-07T06:42:46.73+00:00

Did you use .NET Upgrade Assistant extension or the command line? When you migrated, did you get some errors?

If you migrate successfully, you will not get these errors, Xamarin.Forms and Xamarin.Essentials NuGet packages and namespace will be removed automatically.

Now you can try to open your .csproj file, delete 'ios-arm64', and remove the Xamarin.Forms and Xamarin.Essentials namespace manually. If you can build and run it without any issue, if so you do not need to add these folders.
Anonymous

2023-08-08T08:43:31.6633333+00:00

I upgraded the solution, android and iOS projects. Is solution upgrade is enough or do we need to upgrade the android and iOS projects?

When I create a new MAUI project, I found there is a Platforms folder and on that I found Android and iOS sub folders. But when upgrade no such folders are created on my side, should I create it manually?

Below is the project structure of a MAUI project created. Like that do I need to create all the files and folders?

After migrating, if you can build and run your project normally, it is enough and no need to add other folders. If you have other needs in future development, you can add it as well.

However, if you still have Xamarin.Forms or Essentials nugget packages, it does not migrate successfully. You can check the second image; 19 files were skipped.
Sreejith Sreenivasan 1,001 Reputation points

2023-08-09T14:17:01.86+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

I upgraded the solution, android and iOS projects. Is solution upgrade is enough or do we need to upgrade the android and iOS projects?

Do we need to upgrade solution only or android and iOS projects?
Sreejith Sreenivasan 1,001 Reputation points

2023-08-09T15:39:42.4766667+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

Pending errors when I upgrade the project using upgrade assistant with .Net 6. Upgraded solution, android and ios.

Screenshot:

Pending errors when I upgrade the project using upgrade assistant with .Net 8. Upgraded solution, android and ios.

Always the solution upgrade is success without skipping any files. But android and ios upgradation skipping a lot of files. Please redirect me what mistake I am doing.
Anonymous

2023-08-10T02:07:04.5066667+00:00

Could you share a demo with us?
Sreejith Sreenivasan 1,001 Reputation points

2023-08-10T07:40:21.0066667+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

Here I have uploaded the demo for the migrated project using .Net 6 and Here I have uploaded the demo for the migrated project using .Net 8.
Anonymous

2023-08-11T09:12:50.3066667+00:00

I downloaded your .net 6 project, please refer this Bootstrap your migrated app document and edit your files. I strongly recommended this migrated video from James, here are lots of error and fixed way in it.
Sreejith Sreenivasan 1,001 Reputation points

2023-08-11T14:39:05.2666667+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

I will try this and update you soon.
Sreejith Sreenivasan 1,001 Reputation points

2023-08-11T14:46:24.7233333+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

I have edited the files as per document and all the errors are gone.

Also I have commented the OnRequestPermissionsResult in the MainActivity. Is this make any problem or is there a way to fix it without commenting?

public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults) { Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults); base.OnRequestPermissionsResult(requestCode, permissions, grantResults); }

But I can't run the app on my device bacause the device is not listing in debug section.

But the device is available for all the other projects. Anything else to do to fix this issue?

Answer 1

Anonymous

Hello,

But I can't run the app on my device bacause the device is not listing in debug section.

But the device is available for all the other projects. Anything else to do to fix this issue?

I added the <SingleProject>true</SingleProject> property into my Android project's .csproj file under the first/main property group, closed VS, deleted Bin, Obj, .vs folders.

After starting VS again , I rebuilt and VS allowed me to debug on selected .net targets like a single project Maui solution.

Then, you will get the AAPT error cannot find the mipmap/icon, please set all of files' build action to AndroidResource in the Resource folder.

Then you can run your maui project.

Best Regards,

Leon Lu

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Sreejith Sreenivasan 1,001 Reputation points

2023-08-17T14:50:18.64+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

The demo project was working fine when I add your fixes.

Here is the screenshot that I take when all the issues are fixed.

But when I open the project again now I am getting below errors. I didn't do anything on the project after it was working.

Severity Code Description Project File Line Suppression State Error NU1012 Platform version is not present for one or more target frameworks, even though they have specified a platform: net7.0-android MyProject.Android E:\My Projects\Xamarin.Net7\MyProject-app\MyProject\MyProject.Android\MyProject.Android.csproj 1

Severity Code Description Project File Line Suppression State Error NETSDK1139 The target platform identifier android was not recognized. MyProject C:\Program Files\dotnet\sdk\7.0.400\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.TargetFrameworkInference.targets 113

Severity Code Description Project File Line Suppression State Error NETSDK1139 The target platform identifier ios was not recognized. MyProject C:\Program Files\dotnet\sdk\7.0.400\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.TargetFrameworkInference.targets 113

I feel this is happening due some kind of caches. Do I need to clear any kind of folders like bin and obj.

I added the <SingleProject>true</SingleProject> property into my Android project's .csproj file under the first/main property group, closed VS, deleted Bin, Obj, .vs folders.

In your answer you mentioned to delete the .vs folders, where I can find that kind of folders and is there any similar kind of cache folders need to delete for the proper working of the application? Somewhere I found need to clear the workloads under C:\Program Files\dotnet\metadata\workloads location.
Sreejith Sreenivasan 1,001 Reputation points

2023-08-21T10:57:10.6866667+00:00

@Leon Lu (Shanghai Wicresoft Co,.Ltd.)

I have removed the .vs folder, updated the vs to latest and uninstall the .NET 7 duplicate. After that it is working fine again.

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Issues on MAUI Project upgraded from Xamarin Forms Project

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