Resolved - Create Net 5 UserControl (2024)

I'm trying Net 5 carefully.

I created a Windows Forms App solution with the main form

Added a Net Core Class Library project to use as a multiuse library

I'd like to add a project with the sole purpose of creating a UserControl that can be used by multiple forms.

When I do an Add New Project I can't find anything to create a UserControl.

WinForms support in .NET 5.0 is still a bit rough around the edges. There's no Windows Control Library project template like there is for .NET Framework. I just created a C# Class Library (.NET Core) project and then edited the project file from this:

<Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <TargetFramework>netcoreapp3.1</TargetFramework> </PropertyGroup></Project>

to this:

<Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <TargetFramework>net5.0-windows</TargetFramework> <UseWindowsForms>true</UseWindowsForms> </PropertyGroup></Project>

After building, I was then able to right-click the project in the Solution Explorer and add a user control.

Skydiver said:

You can add a new project that is a library type. Within that project, you can then add a user control.

Click to expand...

I know it has to be simple but I added a class library and then tried add new item to it but could not find the correct item to add.

jmcilhinney said:

WinForms support in .NET 5.0 is still a bit rough around the edges. There's no Windows Control Library project template like there is for .NET Framework. I just created a C# Class Library (.NET Core) project and then edited the project file from this:

XML:

<Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <TargetFramework>netcoreapp3.1</TargetFramework> </PropertyGroup></Project>

to this:

XML:

<Project Sdk="Microsoft.NET.Sdk"> <PropertyGroup> <TargetFramework>net5.0-windows</TargetFramework> <UseWindowsForms>true</UseWindowsForms> </PropertyGroup></Project>

After building, I was then able to right-click the project in the Solution Explorer and add a user control.

Click to expand...

What does <UseWindowsForms>true</UseWindowsForms> do.

Trying Net 5 I could not get System.Windows.Forms to register correctly.

Tried adding that and it seems to fix it. Why?

jmcilhinney said:

Look at the project in the Solution Explorer thoroughly before and after and you'll see what the difference is.

Click to expand...

'Adding <UseWindowsForms>true</UseWindowsForms> to the <PropertyGroup> added the dependencies
'C:\Program Files\dotnet\packs\Microsoft.WindowsDesktop.App.Ref\5.0.0\

I looked in that folder. Is that something special for Net 5 or has that always been there.

Just curious. What is it?

Is it something that I might not need after Net 5 get more mature?

Can I add a comment to the project file that the system will ignore?

It's the directive that tells the IDE to include the WinForms package for .NET 5. I expect that you'll always need it, but the hope would be that they add a project template that does it for you, just as they have with the WinForms application project. I worked out that you could get a class library to work by examining an application project and seeing what was different, then experimenting.

By the way, you can create your own project templates if you want to. I haven't done it for a long time so can't remember the details, which may have changed since I last did it anyway. Basically, you create a project from an existing template, make the changes you want and then export it as a template. If this is a project type you might need again, maybe you should research how exactly to do that.

jmcilhinney said:

WinForms package for .NET 5. I expect that you'll always need itt.

Click to expand...

Good, I don't need to make a note to check this ocassionally.

Thanks - to bad there can only be one reply marked as solution.

MSB3290 Failed to create the wrapper assembly for type library "{215d64d2-031c-33c7-96e3-61794cd1ee61}". Type library 'System_Windows_Forms' was exported from a CLR assembly and cannot be re-imported as a CLR assembly. LibraryNative0 C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets

I'm converting a class library and cleaned up all errors except the above, which I can find no reference to. Can you tell me the kind of thing I should look for in my code.

jmcilhinney said:

The obvious first step is to search for the error code and find out what it means and what existing solutions there may be.

Click to expand...

Naturally, I did, and only got some general suggestion to use community.

I'll try again but I already di a few times.

Edit: I really did not search - I clicked the error message in the error list and thought the was equivalent. Guess not.

If that's the problem, how can I possibly get around it. I need 'tom"

I'll try again to add a reference and see if that helps'

It did not work the first time because I selected the reference rather than checking it - so it really did not get added.

Thanks for the quick reply.