HttpContext.Current.User.Identity.Name is always string.Empty

问题

Hi I use a custom MembershipProvider.

I want to know the current username during an application scenario, but when I try accessing HttpContext.Current.User.Identity.Name it always returns string.Empty.

if (Membership.ValidateUser(tbUsername.Text, tbPassword.Text))
{
    FormsAuthentication.SetAuthCookie(tbUsername.Text, true);
    bool x = User.Identity.IsAuthenticated; //true
    string y = User.Identity.Name; //\"\"
    FormsAuthentication.RedirectFromLoginPage(tbUsername.Text, cbRememberMe.Checked);
}

Am I missing something?

回答1:

FormsAuthentication.SetAuthCookie(tbUsername.Text, true);
bool x = User.Identity.IsAuthenticated; //true
string y = User.Identity.Name; //""

The problem you have is at this point you're only setting the authentication cookie, the IPrincipal that gets created inside the forms authentication module will not happen until there is a new request - so at that point the HttpContext.User is in a weird state. Once the redirect happens then, because it's a new request from the browser the cookie will get read before your page is reached and the correct user object created.

Cookies are only set on the browser after a request is completed.

As an aside RedirectFromLoginPage creates a forms auth cookie anyway, you don't need to do it manually

回答2:

Please try System.Web.HttpContext.Current.Request.LogonUserIdentity.Name instead of User.Identity.Name. It worked for me.

回答3:

The value of HttpContext.Current.User.Identity.Name is set by the call to RedirectFromLoginPage. You can get the current user id from HttpContext.Current.User.Identity.Name once you are redirected to a new page. I'm not sure why you would need to access the user name through the User property in this context, couldn't you just use the value contained in tbUsername.Text?

回答4:

in VS Community 2015 version, if you create a web forms application, it automatically add codes in web.config node to remove FormsAuthentication, try remove below section

<modules>
  <remove name="FormsAuthentication"/>
</modules>

回答5:

As already suggested FormsAuthentication.RedirectFromLoginPage() method, sets the Authentication Cookie automatically.

However in my case, i had nested web applications where i had cleared <httpModules> tag in child application (so that it does not inherit httpModules from its parent application) in the web.config file. Removing the unwanted parent httpModules made everything work again.

its better to check this tag before complicating things :)

回答6:

If you're looking for the name of the user from the membership provider, try something like this ...

var user = Membership.GetUser( HttpContext.Current.User.Identity.Name );

回答7:

If you're using URL rewrite or change your URL,it may be cause return Empty null value.You should try change path of your URL from .html to .aspx or none extendtion. this is issue for my case.You try.I hope this useful

来源：https://stackoverflow.com/questions/1056487/httpcontext-current-user-identity-name-is-always-string-empty