如何在C＃中获取Windows登录名

Question

I have a web-app with C# where I want to get the user's logged in computer name. This page will be called by another web address.

I've tried several ways, but not getting the results as I want it. Here's my code :

1. txtBookBy.Text = WindowsIdentity.GetCurrent().Name;
2. txtBookBy.Text = User.Identity.Name;
3. txtBookBy.Text = Request.ServerVariables[5];
4. txtBookBy.Text = System.Environment.UserName;
5. txtBookBy.Text = Request.ServerVariables["LOGON_USER"];
6. txtBookBy.Text = Request.QueryString["user"];

This's the result, when i called by another web address.

1. txtBookBy.Text = "compName\ASPNET";
2. txtBookBy.Text = "";
3. txtBookBy.Text = "";
4. txtBookBy.Text = "ASPNET";
5. txtBookBy.Text = "";
6. txtBookBy.Text = @Variable;

This's the result, when i run with visual studio.

1. txtBookBy.Text = "PT\asromi";
2. txtBookBy.Text = "PT\asromi";
3. txtBookBy.Text = "PT\asromi";
4. txtBookBy.Text = "asromi";
5. txtBookBy.Text = "PT\asromi";
6. txtBookBy.Text = @Variable;

the results I want : When i called by another web address, the result like "asromi"

some people told me to reconfigure IIS.

1. activate Windows Integrated Authentication
2. turn off anonymous users either

but, i really newbie with IIS. please explain techniques detail, what i have to do.

Answer 1

You can get the user's WindowsIdentity object under Windows Authentication by:

WindowsIdentity identity = HttpContext.Current.Request.LogonUserIdentity;

and then you can get the information about the user like identity.Name.

Please note you need to have HttpContext for these code and WindowsAuthentication should be enabled in Web.config file

<security>
    <authentication>
        <anonymousAuthentication enabled="false" />
        <windowsAuthentication enabled="true" />
    </authentication>
</security>

Answer 2

Try to use the following code

public class DNSHelper
{
    /// <summary>
    /// Gets the username.
    /// </summary>
    /// <param name="request">The request.</param>
    /// <returns></returns>
    public static string GetUsername(System.Web.HttpRequest request)
    {
        try
        {
            return request.LogonUserIdentity.Name;
        }
        catch (InvalidOperationException ioex)
        {
            if (System.Web.HttpContext.Current.User != null)
            {
                return System.Web.HttpContext.Current.User.Identity.Name;
            }
            else
            {
                return string.Empty;
            }
        }
    }
}

Example:

var username = DNSHelper.GetUsername(System.Web.HttpContext.Current.Request);