案例1、主体(包含用户和组)和标识(用户名)的使用。

PrincipalPolicy枚举：主体类型 分为window主体、未认证的主体和未分配主体
GenericPrincipal、GenericIdentity主体类：自定义普通的主体，该主体是认证的。
WindowsPrincipal、WindowsIdentity主体类：系统主体
Thread.CurrentPrincipal = principal; 设置当前线程的主体
IIdentity 、IPrincipal 主体类的接口

#region 当前线程
Thread t = null;

Console.WriteLine("======PrincipalPolicy.WindowsPrincipal===========");

AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal);

t = new Thread(new ThreadStart(CurrentThreadInfo));
t.Start();
t.Join();

Console.WriteLine("======PrincipalPolicy.UnauthenticatedPrincipal===========");
AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.UnauthenticatedPrincipal);
  t = new Thread(new ThreadStart( CurrentThreadInfo));
t.Start();
t.Join();


Console.WriteLine("=====PrincipalPolicy.NoPrincipal===========");
AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.NoPrincipal);
t = new Thread(new ThreadStart(CurrentThreadInfo));
t.Start();
t.Join();






Console.WriteLine("======自定义一个主体===========");

IIdentity identity = new GenericIdentity("MyIdentity");

IPrincipal principal = new GenericPrincipal(identity, new[] { "studentc", "student" });


//AppDomain.CurrentDomain.SetThreadPrincipal(principal);
Thread.CurrentPrincipal = principal;    
t = new Thread(new ThreadStart(CurrentThreadInfo));
t.Start();
t.Join();


static void CurrentThreadInfo()
{
 IPrincipal currentPricipal=   Thread.CurrentPrincipal;

    if (currentPricipal != null )
    {
        Console.WriteLine($"TYPE:{currentPricipal.Identity.GetType().Name}");
        Console.WriteLine($"Name:{currentPricipal.Identity.Name}");
        Console.WriteLine($"IsAuthenticated:{currentPricipal.Identity.IsAuthenticated}");
        if (currentPricipal.IsInRole("student"))
        {
            Console.WriteLine("role:student");

        }
    }
    
    else
    {
        Console.WriteLine("currentPricipal  Is Null");
    }


}

案例二|、

using System.Reflection;
using System.Security.AccessControl;
using System.Security.Permissions;
using System.Security.Principal;
#region 当前进程
//将当前进程设置为安全主体,应用程序默认值为 UnauthenticatedPrincipal。
AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal);



WindowsPrincipal currentProgramePrincipal = (WindowsPrincipal)Thread.CurrentPrincipal;
Type type = typeof(WindowsPrincipal);
Console.WriteLine("===============当前进程的主体 标识 ===========================");
//获取当前进程的主体 标识 
foreach (var item in type.GetProperties())
{
    Console.WriteLine($"{item.Name}:{item.GetValue(currentProgramePrincipal).ToString()}");
    if (item.Name == "Identity")
    {
        WindowsIdentity currentProgrameIdentity = item.GetValue(currentProgramePrincipal) as WindowsIdentity;
        Type currentIdentity = typeof(WindowsIdentity);
        foreach (var ite in currentIdentity.GetProperties())
        {
            Console.WriteLine($"{ite.Name}:{ite.GetValue(currentProgrameIdentity)}");
        }
    }
}
//
Console.WriteLine("===============当前进程主体的角色===========================");

//获取当前进程主体的角色
foreach (var rolename in Enum.GetValues(typeof(WindowsBuiltInRole)))
{
    Console.WriteLine($"{rolename.ToString()}:{currentProgramePrincipal.IsInRole((WindowsBuiltInRole)rolename)}"); ;
}
Console.WriteLine("=================当前用户的标识======================");

//获取当前用户的标识
WindowsIdentity identity = WindowsIdentity.GetCurrent();
Type WindowsIdentityType = typeof(WindowsIdentity);

foreach (var item in WindowsIdentityType.GetProperties())
{
    Console.WriteLine($"{item.Name}:{item.GetValue(identity)}");
}
#endregion