A port of ASP.NET WebForms to .NET 8
$ dotnet add package EstrellasDeEsperanza.WebFormsForCore.BuildWebFormsForCore is an OpenSource library to run WebForms apps on ASP.NET Core. This library provides a port of the System.Web libraries of .NET Framework to .NET 10. With this library, you can run WebForms websites directly in ASP.NET Core, also on Linux. With this library it becomes easy to migrate your existing WebForms application to run on ASP.NET Core also.
We successfully ported the FuseCP Control Panel, a huge WebForms code base, to ASP.NET Core & Linux with the aid of this library. The goal of running FuseCP on Linux without porting everything to Blazor was also our motivation of creating WebFormsForCore.
If you need support porting your project to .NET Core & WebFormsForCore, we provide support for 40$ per hour. Please contact us via the LiveChat button on this page or via WhatsApp. There is also a tutorial on Youtube on how to convert a sample WebForms application to WebFormsForCore.
You can find the source code of WebFormsForCore on GitHub. It is licensed under a MIT license. We welcome contributions, please have a look into the issues if you want to contribute.
If you like WebFormsForCore, and it helped you save a lot of work, please consider to sponsor us on GitHub or donate to us with PayPal.
If you have a WebForms project you want to convert to NET Core, proceed as follows:
First convert your Project to a SDK Project. Please keep a backup of the old non SDK style
project. Conversion can be done easiest by using a converter like the migrate-2019 tool. To install that
tool, run dotnet tool install --global Project2015To2017.Migrate2019.Tool. Then go to the directory
of your solution and run dotnet migrate-2019 wizard to convert your solution to an SDK project. If
the converter complains about an unsupported project type, remove the <ProjectTypeGuid> property from
the project first. After conversion change the target framework of your project to . You
might also keep , in order to dual run your project with NET Framework & NET Core.
Change the OutputPath for to :
net10.0net48net10.0bin_dotnet<PropertyGroup>
<AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
<AppendRuntimeIdentifierToOutputPath>false</AppendRuntimeIdentifierToOutputPath>
<IntermediateOutputPath>$(BaseIntermediateOutputPath)$(Configuration)\$(TargetFramework.ToLowerInvariant())\</IntermediateOutputPath>
</PropertyGroup>
<PropertyGroup Condition="'$(TargetFramework)' != 'net48'">
<OutputType>Exe</OutputType>
<OutputPath>bin_dotnet</OutputPath>
<StartupObject>Program</StartupObject>
</PropertyGroup>
<PropertyGroup Condition="'$(TargetFramework)' == 'net48'">
<OutputType>Library</OutputType>
<OutputPath>bin</OutputPath>
</PropertyGroup>
<ItemGroup>
<Content Remove="bin_dotnet\**\*.*" />
<Reference Remove="bin_dotnet\**\*.*" />
<None Remove="bin_dotnet\**\*.*" />
<Compile Remove="bin_dotnet\**\*.*" />
</ItemGroup>
Then, for net10.0, import the WebFormsForCore packages like so:
<ItemGroup Condition="'$(TargetFramework)' == 'net10.0'">
<PackageReference Include="EstrellasDeEsperanza.WebFormsForCore.Web" Version="1.4.6" />
</ItemGroup>
Remove the old Reference references or put them in a condition only for net48.
If your project also needs System.Web.Extensions or System.Web.Optimization import the
corresponding packages also, like EstrellasDeEsperanza.WebFormsForCore.Web.Extensions or
EstrellasDeEsperanza.WebFormsForCore.Web.Optimization etc. The following packages are available:
System.Configuration: EstrellasDeEsperanza.WebFormsForCore.ConfigurationSystem.Web: EstrellasDeEsperanza.WebFormsForCore.WebSystem.Web.Services: EstrellasDeEsperanza.WebFormsForCore.Web.ServicesSystem.Web.Extensions: EstrellasDeEsperanza.WebFormsForCore.Web.ExtensionsSystem.Web.Optimization: EstrellasDeEsperanza.WebFormsForCore.Web.OptimizationSystem.Web.Mobile: EstrellasDeEsperanza.Web.MobileMicrosoft.AspNet.Web.Optimization.WebForms: EstrellasDeEsperanza.WebFormsForCore.Web.Optimization.WebFormsWebGrease: EstrellasDeEsperanza.WebFormsForCore.WebGreaseSystem.Drawing: EstrellasDeEsperanza.WebFormsForCore.DrawingAjaxControlToolkit: EstrellasDeEsperanza.WebFormsForCore.AjaxControlToolkitAjaxControlToolkit.HtmlEditor.Sanitizer: EstrellasDeEsperanza.WebFormsForCore.AjaxControlToolkit.HtmlEditor.SanitizerAjaxControlToolkit.StaticResources: EstrellasDeEsperanza.WebFormsForCore.AjaxControlToolkit.StaticResourcesSystem.Drawing only implements Attributes, so WebFormsForCore can run on Linux, where System.Drawing.Common.dll is missing.
If you want WebFormsForCore to automatically create the *.designer.cs files for you, as it was in the old non
SDK project, you also need to import the package EstrellasDeEsperanza.WebFormsForCore.Build like so:
<PackageReference Include="EstrellasDeEsperanza.WebFormsForCore.Build" Version="1.4.6" ExcludeAssets="runtime" />
If you import this package, outdated *.designer.cs files will be created after build. This only works for C#,
not for VisualBasic. Also, the visual designers in VisualStudio for web controls are not supported and won't
work.
Also, the Build package will strip incompatible designer attributes from classes in legacy .NET Framework assemblies after build, that would otherwise cause the types load to fail.
Finally configure ASP.NET Core to use WebForms in the initialization code Program.cs like so:
#if NETCOREAPP
using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;
public class Program
{
public static void Main(string[] args)
{
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.UseWebForms();
app.Run();
}
}
#endif
Usually this will cause WebFormsForCore to handle all WebForms requests, like aspx pages etc.
Requests not specific to WebForms will be handled by ASP.NET Core. If you want all requests to
be handled by WebForms, for example if your application uses routing and friendly urls, you might
want to call app.UseWebForms(opt => opt.HandleAllRequestsWithWebForms())
Currently there might be some conflicts with the packages System.Web.dll, System.Drawing.dll & System.Configuration.ConfigurationManager.dll, since WebFormsForCore replaces those dll's. In order to prevent the import of the old dll's include the following in your csproj:
<Target Name="ChangeAliasesOfNugetRefs" BeforeTargets="FindReferenceAssembliesForReferences;ResolveReferences">
<ItemGroup>
<!-- Do not import System.Configuration.ConfigurationManage -->
<ReferencePath Remove="%(Identity)" Condition="'%(FileName)' == 'System.Configuration.ConfigurationManager' AND $([System.Text.RegularExpressions.Regex]::IsMatch(%(Identity),'(?i)system\.configuration\.configurationmanager\\[.0-9]+\\'))" />
<!-- Do not import System.Web -->
<ReferencePath Remove="%(Identity)" Condition="'%(FileName)' == 'System.Web' AND $([System.Text.RegularExpressions.Regex]::IsMatch(%(Identity),'\\dotnet\\'))" />
<!-- Do not import System.Drawing -->
<ReferencePath Remove="%(Identity)" Condition="'%(FileName)' == 'System.Drawing' AND $([System.Text.RegularExpressions.Regex]::IsMatch(%(Identity),'\\dotnet\\'))" />
</ItemGroup>
</Target>