Can't change runtime version of produced DLL in ASP.NET Core Web App

Question

I am building a .NET 5 based ASP.NET Web Application for REST APIs. It is a proof-of-concept at the moment. My hosting provider only supports 5.0.2 runtime but the SDK version came with .NET 5.0.103 (runtime 5.0.3) installed. I need to produce DLL with a target runtime of 5.0.2.

In order to be able to produce DLL for runtime 5.0.2, I installed .NET SDK version 5.0.102.

Now, I have SDKs and Runtimes as below (dotnet --info):

.NET SDKs installed:

• 5.0.102 [C:\Program Files\dotnet\sdk]
• 5.0.103 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:

• Microsoft.AspNetCore.App 5.0.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
• Microsoft.AspNetCore.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]

I tried to force use of an earlier version using a global.json file. I put the file in the folder where the .csproj file exists. The content is as below:

{
  "sdk": {
    "version": "5.0.102"
  }
}

dotnet --version and dotnet --info also report the SDK in use is 5.0.102 if I run these commands from the project directory:

D:\Projects-DriveD\VS\AspNetCoreWebSample\AspNetCoreWebSample>dotnet --version
5.0.102

D:\Projects-DriveD\VS\AspNetCoreWebSample\AspNetCoreWebSample>dotnet --info
.NET SDK (reflecting any global.json):
 Version:   5.0.102
 Commit:    71365b4d42

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.19042
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\5.0.102\

Host (useful for support):
  Version: 5.0.3  <==========================================
  Commit:  c636bbdc8a

.NET SDKs installed:
  5.0.102 [C:\Program Files\dotnet\sdk]
  5.0.103 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 5.0.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]

But even then, the DLL produced is targeting the runtime version 5.0.3. I think the problem could be because of Host Version is still 5.0.3, but I am not entirely sure.

I am verifying the runtime version of produced DLL using the Jetbrains dotpeek tool.

How can I force Visual Studio to produce a DLL which targets runtime version 5.0.2 instead of 5.0.3?

Answer 1

From the official documentation Select the .NET version to use :

The RuntimeFrameworkVersion element overrides the default version policy. For self-contained deployments, the RuntimeFrameworkVersion specifies the exact runtime framework version. For framework-dependent applications, the RuntimeFrameworkVersion specifies the minimum required runtime framework version.

In your csproj, you can add :

<RuntimeFrameworkVersion>5.0.2</RuntimeFrameworkVersion>