Export (0) Print
Expand All

Membership.GetUserNameByEmail Method

Gets a user name where the e-mail address for the user matches the specified e-mail address.

Namespace:  System.Web.Security
Assembly:  System.Web (in System.Web.dll)

public static string GetUserNameByEmail(
	string emailToMatch
)

Parameters

emailToMatch
Type: System.String

The e-mail address to search for.

Return Value

Type: System.String
The user name where the e-mail address for the user matches the specified e-mail address. If no match is found, null is returned.

GetUserNameByEmail can be used to retrieve the user name for a membership user in the case where a user does not know their user name, but does know their e-mail address. If more than one user in the data store has the same e-mail address, the first user name encountered is returned.

Leading and trailing spaces are trimmed from all parameter values.

The following code example retrieves the user name for a specified e-mail address.

Security noteSecurity Note

This example contains a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

<%@ Page Language="C#" %>
<%@ Import Namespace="System.Web.Security" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

public void Search_OnClick(object sender, EventArgs args)
{
  string username = Membership.GetUserNameByEmail(EmailTextBox.Text);

  if (username == null)
  {
    Msg.Text = "E-mail address " + Server.HtmlEncode(EmailTextBox.Text) + " is not found. Please reenter.";
  }
  else
  {
    Msg.Text = "The user name for " + Server.HtmlEncode(EmailTextBox.Text) + 
               " is " + Server.HtmlEncode(username) + ".";
  }

}

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Sample: Retrieve Username By E-mail</title>
</head>
<body>

<form id="form1" runat="server">
  <h3>Forgot your Username? Search for it by e-mail address.</h3>

  <asp:Label id="Msg" runat="server" ForeColor="maroon" /><br />

  E-mail address: <asp:Textbox id="EmailTextBox" Columns="30" runat="server" />
                  <asp:RequiredFieldValidator id="EmailRequiredValidator" runat="server"
                                        ControlToValidate="EmailTextBox" ForeColor="red"
                                        Display="Static" ErrorMessage="Required" /><br />

  <asp:Button id="SearchButton" Text="Search" 
              OnClick="Search_OnClick" runat="server" />

</form>

</body>
</html>

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Show:
© 2014 Microsoft