在Winform中使用UI事件时设置CurrentPrincipal失败

<configuration>
  <system.web>
    <authentication mode="Windows" />
    <authorization>
      <deny users="?" />
    </authorization>
  </system.web>
</configuration>

public class CustomIdentity : IIdentity
{
    public string AuthenticationType => "CustomAuthentication";
    public bool IsAuthenticated => true;
    public string Name => "John Doe";
}

public class CustomPrincipal : IPrincipal
{
    private readonly IIdentity _identity;

    public CustomPrincipal(IIdentity identity)
    {
        _identity = identity;
    }

    public IIdentity Identity => _identity;
    public bool IsInRole(string role) => role == "Admin";
}

var customIdentity = new CustomIdentity();
var customPrincipal = new CustomPrincipal(customIdentity);
Thread.CurrentPrincipal = customPrincipal;