Sigin as different user in asp.net using Windows authentication

Wed 20 Apr 2011

If you want to have signin as different user functionality like sharepoint in your asp.net application, following workaround you might be looking for.
After setting your web.config file's

<authentication mode="Windows" />

and in IIS after remove anonymous authentication and enable windows authentication, have following code snippet where you want to have this functionality

In your aspx page

<div>You are logged in as <br /> <%=User.Identity.Name%> <br /><br />
<asp:LinkButton ID="lnkSignOut" runat="server" Text="Sign in as different user" onclick="lnkSignOut_Click"></asp:LinkButton>

In your code behind file

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        Session["logOutRequested"] = false; //Initialize value. This will be set to true when user will click on sign in as differnet user
    }
}

protected void lnkSignOut_Click(object sender, EventArgs e)
{
    if (null != Session["logOutRequested"] && !Convert.ToBoolean(Session["logOutRequested"])) // Check if user is clicking link first time
    {
        Session["logOutRequested"] = true; //Set value that user want to sign in as differnet user
        Response.StatusCode = 401;
        Response.StatusDescription = "Unauthorized";
        Response.End();
    }
    else
    {
        Session["logOutRequested"] = false; //Initialize value again after user is authenticated with differnet or same user again.
    }
}

Hope this workaround will help.