Login.LoggingIn 事件

参考

定义

命名空间:: System.Web.UI.WebControls

程序集:: System.Web.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

在用户未进行身份验证而提交登录信息时出现。

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

事件类型

LoginCancelEventHandler

示例

下面的代码示例使用 LoggingIn 事件来确保用户在属性中 UserName 输入了格式正确的电子邮件地址。否则，事件 LoggingIn 将取消登录尝试并使用属性显示错误消息 InstructionText 。

<%@ 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>