The type or namespace name 'PrincipalContext' could not be found-CodePudding

When attempting to run below C# code in VSCode, I got the following the error message. How can I solve this?

Error message:

[{
    "resource": "/c:/C#/app/Program.cs",
    "owner": "csharp",
    "code": "CS0246",
    "severity": 8,
    "message": "The type or namespace name 'PrincipalContext' could not be found (are you missing a using directive or an assembly reference?) [app]",
    "source": "csharp",
    "startLineNumber": 9,
    "startColumn": 29,
    "endLineNumber": 9,
    "endColumn": 45
},{
    "resource": "/c:/C#/app/Program.cs",
    "owner": "csharp",
    "code": "CS0103",
    "severity": 8,
    "message": "The name 'ContextType' does not exist in the current context [app]",
    "source": "csharp",
    "startLineNumber": 9,
    "startColumn": 46,
    "endLineNumber": 9,
    "endColumn": 57
},{
    "resource": "/c:/C#/app/Program.cs",
    "owner": "csharp",
    "code": "CS0103",
    "severity": 8,
    "message": "The name 'GroupPrincipal' does not exist in the current context [app]",
    "source": "csharp",
    "startLineNumber": 11,
    "startColumn": 19,
    "endLineNumber": 11,
    "endColumn": 33
},{
    "resource": "/c:/C#/app/Program.cs",
    "owner": "csharp",
    "code": "CS0246",
    "severity": 8,
    "message": "The type or namespace name 'PrincipalContext' could not be found (are you missing a using directive or an assembly reference?) [app]",
    "source": "csharp",
    "startLineNumber": 13,
    "startColumn": 33,
    "endLineNumber": 13,
    "endColumn": 49
},{
    "resource": "/c:/C#/app/Program.cs",
    "owner": "csharp",
    "code": "CS0103",
    "severity": 8,
    "message": "The name 'ContextType' does not exist in the current context [app]",
    "source": "csharp",
    "startLineNumber": 13,
    "startColumn": 50,
    "endLineNumber": 13,
    "endColumn": 61
},{
    "resource": "/c:/C#/app/Program.cs",
    "owner": "csharp",
    "code": "CS0103",
    "severity": 8,
    "message": "The name 'IdentityType' does not exist in the current context [app]",
    "source": "csharp",
    "startLineNumber": 15,
    "startColumn": 36,
    "endLineNumber": 15,
    "endColumn": 48
}]

Code

string UserDomain = Environment.UserDomainName.ToString();
string UserName = Environment.UserName.ToString();
Console.WriteLine(UserDomain);
Console.WriteLine(Environment.UserName);


try
{
   using (var pcLocal = new PrincipalContext(ContextType.Machine))
   {
      var group = GroupPrincipal.FindByIdentity(pcLocal, "Administrators");

      using (var pcDomain = new PrincipalContext(ContextType.Domain, "UserDomain"))
      {
       group.Members.Add(pcDomain, IdentityType.SamAccountName, "UserName");                            
         group.Save();
      };
   };
} catch (Exception e)
{
   Console.WriteLine(e.Message);
};

app.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="System.DirectoryServices" Version="7.0.0-preview.6.22324.4" />
    <PackageReference Include="System.DirectoryServices.AccountManagement" Version="7.0.0-preview.6.22324.4" />
  </ItemGroup>

</Project>

CodePudding user response：

PrincipalContext is in System.DirectoryServices.AccountManagement namespace so beside installing the package (which you appear to have done correctly), you need to declare that you are using that namespace as well:

// Either put this on top:
using System.DirectoryServices.AccountManagement

// Or use fully qualified name:
using (var pcLocal = new System.DirectoryServices.AccountManagement.PrincipalContext(ContextType.Machine))

A side note: you can also use this using statement since you wrap it for the whole code block:

using var pcLocal = new PrincipalContext(ContextType.Machine);