How to tell Visual Studio which runtime to build for

Question

How can I tell Visual Studio to build against multiple runtimes?

I've created a simple .NET Core (1.0) console application (Hello World with HTTP download). I want to build it for multiple RIDs (win7-x64, win10-x64, etc) so that I can publish it and include the dependencies for a stand-alone application running on Windows 2008 R2 (win7-x64). But my developer machine where I'm building this is Windows 10, so VS picks win10-x64 so my publish task doesn't find any files for win7-x64. I also want to build specifically for win10-x64, so even if I can force it by removing the rest of the RIDs, I want the option to build against multiple.

I know I can do this with MSBuild and dotnet cli, but I'd like to know how to do it from within VS.

project.json:

{
  "version": "1.0.0-*",
  "buildOptions": {
    "emitEntryPoint": true
  },

  "dependencies": {
    "Microsoft.NETCore.App": "1.1.0",
    "System.Net.Http": "4.1.0"
  },

  "runtimes": {
    "win10-x64": {},
    "win81-x64": {},
    "win8-x64": {},
    "win7-x64": {}
  },

  "frameworks": {
    "netcoreapp1.0": {
      "imports": "dnxcore50"
    }
  }
}

Note that I'm using System.Net.Http which requires different dependencies in win7 vs win10 to test. If I run the win10-x64 on Win2k8 then it will fail because it's missing dependencies for the runtime on win7.

It shouldn't matter, but for reference here's the main code block, program.cs:

using System;

namespace TestOnWindows2008
{
    public class Program
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Hello World");

            using (var httpClient = new System.Net.Http.HttpClient())
            {
                string result = httpClient.GetStringAsync("https://www.microsoft.com/en-us/").Result;

                Console.WriteLine(result.Substring(0, 200));
            }

            Console.WriteLine("Done");
        }
    }
}

Answer 1

Although I am not directly answering your question, maybe it will help you.

Since your target platform is win7-x64, which is older than your development platform, win10-x64, you can keep only win7-x64 and use it for both debugging and publishing.

I've just tested you code using Windows 10 x64 Enterprise and everything went ok.

project.json

{
  "version": "1.0.0-*",
  "buildOptions": {
    "emitEntryPoint": true
  },

  "dependencies": {
    "Microsoft.NETCore.App": "1.1.0",
    "System.Net.Http": "4.1.0"
  },

  "runtimes": {
    "win7-x64": {}
  },

  "frameworks": {
    "netcoreapp1.0": {
      "imports": "dnxcore50"
    }
  }
}

And Program.cs is the one from your question.

Here is the output:

for run:

C:\temp\test2>dotnet restore && dotnet run

log : Restoring packages for C:\temp\test2\project.json...

log : Writing lock file to disk. Path: C:\temp\test2\project.lock.json

log : C:\temp\test2\project.json

log : Restore completed in 2603ms.

Project test2 (.NETCoreApp,Version=v1.0) will be compiled because expected outputs are missing

Compiling test2 for .NETCoreApp,Version=v1.0

Compilation succeeded.

0 Warning(s)
0 Error(s)

Time elapsed 00:00:01.7257991

Hello World

Done

And for publish

C:\temp\test2>dotnet publish

Publishing test2 for .NETCoreApp,Version=v1.0/win7-x64

Project test2 (.NETCoreApp,Version=v1.0) was previously compiled. Skipping compilation.

publish: Published to C:\temp\test2\bin\Debug\netcoreapp1.0\win7-x64\publish

Published 1/1 projects successfully