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GetUserNameByEmail Method

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
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