Login.LoggingIn Login.LoggingIn Login.LoggingIn Login.LoggingIn Event

定义

在用户未进行身份验证而提交登录信息时出现。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 

示例

下面的代码示例使用LoggingIn事件,以确保用户输入中的格式正确的电子邮件地址UserName属性。The following code example uses the LoggingIn event to ensure that the user has entered a well-formed email address in the UserName property. 如果没有,则LoggingIn事件取消的登录尝试,并显示错误消息使用InstructionText属性。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>

注解

LoggingIn当用户提交登录信息但之前对用户进行身份在网站上引发事件。The LoggingIn event is raised when a user submits login information but before the user is authenticated on the Web site. 使用LoggingIn事件来设置对用户进行身份验证之前需要的任何信息。Use the LoggingIn event to set up any information that you need before authenticating a user.

您可以取消登录尝试期间LoggingIn通过设置事件Cancel的属性CancelEventArgs对象传递给trueYou can cancel a login attempt during the LoggingIn event by setting the Cancel property of the CancelEventArgs object to true.

之后LoggingIn引发事件时,Login控件将引发Authenticate事件,然后LoggedIn事件。After the LoggingIn event is raised, the Login control raises the Authenticate event and then the LoggedIn event.

有关处理事件的详细信息,请参阅处理和引发事件For more information about handling events, see Handling and Raising Events.

适用于

另请参阅