Xamarin to MAUI: When setting <UseMaui>true</UseMaui> in csproj, my xaml.cs files are removed

Question

Xamarin to MAUI: When setting <UseMaui>true</UseMaui> in csproj, my xaml.cs files are removed

Franklin 11

Within the csproj file, when setting the tag <UseMaui>true</UseMaui>, all xaml.cs files that were used with Xamarin are removed. When setting <UseMaui>false</UseMaui> all xaml.cs files are returned.

This happens when using the upgrade assistant or doing the migration manually.

Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 36,436 Reputation points Microsoft External Staff

2023-05-25T06:12:29.84+00:00

You upgrade your Xamarin.Forms app to .NET MAUI with the .NET Upgrade Assistant, right？Do you choose in-place project upgrade or side-by-side project upgrade? And for .NET6 or .NET7 or .NET8? What's the detailed VS version?

(I try to upgrade a Xamrin.Forms app to .net7 MAUI app with upgrade assistant, it works. I cannot reproduce the issue.)

In addition, you meet the same issue when doing the migration manually. Do you mean you still have the problem when you create an empty template MAUI project?

Would you mind sharing the .csproj file with me?

Franklin 11

Hi Wenyan,

Yes, I did follow the steps on upgrading from Xamarin.Form to .NET MAUI with upgrade assitant.

I also tried to do it manually, by upgrading the csproj and other files.

I tried doing .NET6 and .NET7.

VS Studio Community 2022 for Mac

When I do it manually I update the csporj to meet the .NET MAUI standards. No I have not tried creating a empty MAUI project and carry the Xamarin.Forms project over.

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <UseMaui>true</UseMaui>
    <TargetFrameworks>net6.0-android;net6.0-ios</TargetFrameworks>
    <OutputType>Library</OutputType>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>
  <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|net7.0-ios|AnyCPU'">
    <CreatePackage>false</CreatePackage>
  </PropertyGroup>

 <ItemGroup>
    <Reference Include="netstandard" />
  </ItemGroup>

<ItemGroup>
    <None Update="Views\VideoView.cshtml">
      <Generator>RazorTemplatePreprocessor</Generator>
      <LastGenOutput>VideoView.cs</LastGenOutput>
    </None>
  </ItemGroup>
  <ItemGroup>
    <Compile Condition=" '$(EnableDefaultCompileItems)' == 'true' " Update="Views\VideoView.cs">
      <DependentUpon>VideoView.cshtml</DependentUpon>
    </Compile>
  </ItemGroup>
  <ItemGroup>
    <Folder Include="RequiredAssets\jquery\images\" />
  </ItemGroup>
</Project>

Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 36,436 Reputation points Microsoft External Staff

2023-05-26T07:45:07.3966667+00:00

When you do the migration manually, you could create an empty MAUI project as described at Upgrade Xamarin.Android, Xamarin.iOS, and Xamarin.Mac projects to .NET - .NET MAUI | Microsoft Learn

(Manually upgrade a Xamarin.Forms app to .NET MAUI - .NET MAUI | Microsoft Learn)

To simplify the upgrade process, we recommend creating a new .NET project of the same type and name as your Xamarin native project, and then copying in your code.

In addition, what's the detailed VS for Mac version? How did you use upgrade assistant? by running the command? You could also try installing the .NET Upgrade Assistant extension via Visual Studio 2022 version 17.6 or later (not VS for Mac), and check if the issue still exists.
Franklin 11 Reputation points

2023-05-30T15:32:58.11+00:00
When creating a new project, do I need to use the .NET MAUI App template or does my app need to be on .NET 6 or .NET 7 to be MAUI compatible?

VS for Mac version: Visual Studio Community 2022 for Mac Version 17.5.6 (build 3)

How did you use upgrade assistant:

Close VS

Lanuch Terminal

Navigate to csproj

Run command: upgrade-assistant upgrade DOMA.csproj --non-interactive --ignore-unsupported-features

1 answer

Your answer

Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 36,436 Reputation points Microsoft External Staff

2023-05-25T06:12:29.84+00:00

You upgrade your Xamarin.Forms app to .NET MAUI with the .NET Upgrade Assistant, right？Do you choose in-place project upgrade or side-by-side project upgrade? And for .NET6 or .NET7 or .NET8? What's the detailed VS version?

(I try to upgrade a Xamrin.Forms app to .net7 MAUI app with upgrade assistant, it works. I cannot reproduce the issue.)

In addition, you meet the same issue when doing the migration manually. Do you mean you still have the problem when you create an empty template MAUI project?

Would you mind sharing the .csproj file with me?
Franklin 11 Reputation points

2023-05-25T15:13:57.0666667+00:00

Hi Wenyan,

Yes, I did follow the steps on upgrading from Xamarin.Form to .NET MAUI with upgrade assitant.

I also tried to do it manually, by upgrading the csproj and other files.

I tried doing .NET6 and .NET7.

VS Studio Community 2022 for Mac

When I do it manually I update the csporj to meet the .NET MAUI standards. No I have not tried creating a empty MAUI project and carry the Xamarin.Forms project over.

<Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <UseMaui>true</UseMaui> <TargetFrameworks>net6.0-android;net6.0-ios</TargetFrameworks> <OutputType>Library</OutputType> <ImplicitUsings>enable</ImplicitUsings> </PropertyGroup> <PropertyGroup Condition="'$(Configuration)|$(TargetFramework)|$(Platform)'=='Debug|net7.0-ios|AnyCPU'"> <CreatePackage>false</CreatePackage> </PropertyGroup> <ItemGroup> <Reference Include="netstandard" /> </ItemGroup> <ItemGroup> <None Update="Views\VideoView.cshtml"> <Generator>RazorTemplatePreprocessor</Generator> <LastGenOutput>VideoView.cs</LastGenOutput> </None> </ItemGroup> <ItemGroup> <Compile Condition=" '$(EnableDefaultCompileItems)' == 'true' " Update="Views\VideoView.cs"> <DependentUpon>VideoView.cshtml</DependentUpon> </Compile> </ItemGroup> <ItemGroup> <Folder Include="RequiredAssets\jquery\images\" /> </ItemGroup> </Project>
Wenyan Zhang (Shanghai Wicresoft Co,.Ltd.) 36,436 Reputation points Microsoft External Staff

2023-05-26T07:45:07.3966667+00:00

When you do the migration manually, you could create an empty MAUI project as described at Upgrade Xamarin.Android, Xamarin.iOS, and Xamarin.Mac projects to .NET - .NET MAUI | Microsoft Learn

(Manually upgrade a Xamarin.Forms app to .NET MAUI - .NET MAUI | Microsoft Learn)

To simplify the upgrade process, we recommend creating a new .NET project of the same type and name as your Xamarin native project, and then copying in your code.

In addition, what's the detailed VS for Mac version? How did you use upgrade assistant? by running the command? You could also try installing the .NET Upgrade Assistant extension via Visual Studio 2022 version 17.6 or later (not VS for Mac), and check if the issue still exists.
Franklin 11 Reputation points

2023-05-30T15:32:58.11+00:00

When creating a new project, do I need to use the .NET MAUI App template or does my app need to be on .NET 6 or .NET 7 to be MAUI compatible?

VS for Mac version: Visual Studio Community 2022 for Mac Version 17.5.6 (build 3)

How did you use upgrade assistant:

Close VS

Lanuch Terminal

Navigate to csproj

Run command: upgrade-assistant upgrade DOMA.csproj --non-interactive --ignore-unsupported-features

Answer 1

Bruce (SqlWork.com) 78,086 Volunteer Moderator

MAUI runs on the .net 6 or net 7 runtime. Xamarin forms run on a custom mono runtime. So a particular app needs to be one or the other. You can not use Xarmarin forms with a Maui app, they must be upgraded to Maui forms.

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Xamarin to MAUI: When setting <UseMaui>true</UseMaui> in csproj, my xaml.cs files are removed

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