c# - System.Net.Http vs Microsoft.Net.Http

Question

I am using ASP.NET Core. I want to use HttpClient but I noticed that there are two NuGet packages being offered. Which one do I use?

• System.Net.Http
• Microsoft.Net.Http

Answer 1

Depends on the version. The old System.Net.Http packages (the 2.0 ones) are legacy packages which are deprecated in favor of Microsoft.Http.Net according to the description:

Legacy package, System.Net.Http is now included in the 'Microsoft.Net.Http' package.

They exist to provide the HttpClient in previous .NET versions and Portable Class libraries. You should use Microsoft.Net.Http in that case.

Since you're using .NET Core, you should use the latest System.Net.Http package (eg. 4.3.3).

Updated for csproj

As of .NET Standard 2.0, the System.Net.HttpClient package is already included and available when you target netstandard2.0. If, for some reason, you still want to reference it for both full .NET and .NET Core, you can add this to your csproj file:

<ItemGroup Condition=" '$(TargetFramework)' == 'net461' ">
    <!-- // HttpClient for full .NET -->
    <Reference Include="System.Net.Http" />
</ItemGroup>
<ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
    <!-- // HttpClient for .NET Core -->
    <PackageReference Include="System.Net.Http" Version="4.3.3" />
</ItemGroup>

---

If you're using project.json

If your project.json targets both full .NET and .NET Core, you have to add the System.Net.Http assembly to the frameworkAssemblies element. For example:

"frameworks": {
  "net451": {
    "frameworkAssemblies": {
      "System.Net.Http": "4.0.0.0" // HttpClient for full .NET
    }
  },
  "netstandard1.3": {
    "dependencies": {
      "System.Net.Http": "4.1.0", // HttpClient for .NET Core
    }
  }
}