Redigeeri

Jagamisviis:

Login.LoggingIn Event

  • Reference

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Occurs when a user submits login information, before authentication takes place.

public:
 event System::Web::UI::WebControls::LoginCancelEventHandler ^ LoggingIn;
public event System.Web.UI.WebControls.LoginCancelEventHandler LoggingIn;
member this.LoggingIn : System.Web.UI.WebControls.LoginCancelEventHandler 
Public Custom Event LoggingIn As LoginCancelEventHandler

Event Type

LoginCancelEventHandler

Examples

The following code example uses the LoggingIn event to ensure that the user has entered a well-formed email address in the UserName property. If not, the LoggingIn event cancels the login attempt and displays an error message using the InstructionText property.

<%@ Page Language="C#" %>
<%@ Import Namespace="System.ComponentModel" %>
<%@ Import Namespace="System.Text.RegularExpressions" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

bool IsValidEmail(string strIn)
{
    // Return true if strIn is in valid email format.
    return Regex.IsMatch(strIn, @"^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$"); 
}

void OnLoggingIn(object sender, System.Web.UI.WebControls.LoginCancelEventArgs e)
{
    if (!IsValidEmail(Login1.UserName))
    {
        Login1.InstructionText = "You must enter a valid email address.";
        e.Cancel = true;
    }
    else
    {
        Login1.InstructionText = String.Empty;
    }
}

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
        <form id="form1" runat="server">
            <asp:Login id="Login1" runat="server" 
                OnLoggingIn="OnLoggingIn" 
                UserNameLabelText="Email Address:" 
                UserNameRequiredErrorMessage="Email Address.">
            </asp:Login>
        </form>
    </body>
</html>

<%@ Page Language="VB" %>
<%@ Import Namespace="System.ComponentModel" %>
<%@ Import Namespace="System.Text.RegularExpressions" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">

Function IsValidEmail(ByVal strIn As String) As Boolean
    ' Return true if strIn is in valid email format.
    Return Regex.IsMatch(strIn, ("^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$"))
End Function

Sub OnLoggingIn(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.LoginCancelEventArgs)
    If Not IsValidEmail(Login1.UserName) Then
        Login1.InstructionText = "You must enter a valid email address."
        e.Cancel = True
    Else
        Login1.InstructionText = String.Empty
    End If
End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
        <form id="form1" runat="server">
            <asp:Login id="Login1" runat="server" 
                OnLoggingIn="OnLoggingIn" 
                UserNameLabelText="Email Address:" 
                UserNameRequiredErrorMessage="Email Address.">
            </asp:Login>
        </form>
    </body>
</html>

Remarks

The LoggingIn event is raised when a user submits login information but before the user is authenticated on the Web site. Use the LoggingIn event to set up any information that you need before authenticating a user.

You can cancel a login attempt during the LoggingIn event by setting the Cancel property of the CancelEventArgs object to true.

After the LoggingIn event is raised, the Login control raises the Authenticate event and then the LoggedIn event.

For more information about handling events, see Handling and Raising Events.

Applies to

See also