ServerValidateEventHandler 委托

表示将处理 CustomValidator 控件的 ServerValidate 事件的方法。

**命名空间:**System.Web.UI.WebControls
**程序集:**System.Web(在 system.web.dll 中)

语法

声明
Public Delegate Sub ServerValidateEventHandler ( _
    source As Object, _
    args As ServerValidateEventArgs _
)
用法
Dim instance As New ServerValidateEventHandler(AddressOf HandlerMethod)
public delegate void ServerValidateEventHandler (
    Object source,
    ServerValidateEventArgs args
)
public delegate void ServerValidateEventHandler (
    Object^ source, 
    ServerValidateEventArgs^ args
)
/** @delegate */
public delegate void ServerValidateEventHandler (
    Object source, 
    ServerValidateEventArgs args
)
JScript 支持使用委托,但不支持进行新的声明。

参数

  • source
    事件源。

备注

使用此委托以提供执行服务器验证的自定义代码。代码需要验证传递给该委托的 args 参数的 Value 属性。在 args 参数的 IsValid 属性中存储验证的结果。

当创建 ServerValidateEventHandler 委托时,将标识处理事件的方法。若要使该事件与事件处理程序相关联,请将该委托的一个实例添加到事件中。除非移除了该委托,否则每当发生该事件时就调用事件处理程序。有关事件处理程序委托的更多信息,请参见 事件和委托

有关处理事件的更多信息,请参见 使用事件

示例

下面的示例说明如何指定和编写服务器端 CustomValidator 的处理程序。它显示输入到文本框中的数字是奇数还是偶数。

<%@ Page Language="VB" AutoEventWireup="True" %>

<html>
<head>

   <script runat="server">

      Sub ValidateBtn_OnClick(sender As Object, e As EventArgs) 

         ' Display whether the page passed validation.
         If Page.IsValid Then 

            Message.Text = "Page is valid."

         Else 

            Message.Text = "Page is not valid!"

         End If

      End Sub

      Sub ServerValidation(source As Object, args As ServerValidateEventArgs)

         Try 

            ' Test whether the value entered into the text box is even.
            Dim num As Integer = Integer.Parse(args.Value)
            args.IsValid = ((num mod 2) = 0)
 
         Catch ex As Exception
         
            args.IsValid = false

         End Try

      End Sub

   </script>    

</head>
<body>

   <form runat="server">
  
      <h3>CustomValidator ServerValidate Example</h3>

      <asp:Label id="Message"
           Text="Enter an even number:" 
           Font-Name="Verdana" 
           Font-Size="10pt" 
           runat="server" />

      <p>

      <asp:TextBox id="Text1" 
           runat="server" />
    
      &nbsp;&nbsp;

      <asp:CustomValidator id="CustomValidator1"
           ControlToValidate="Text1"
           Display="Static"
           ErrorMessage="Not an even number!"
           ForeColor="green"
           Font-Name="verdana" 
           Font-Size="10pt"
           OnServerValidate="ServerValidation"
           runat="server"/>

      <p>
 
      <asp:Button id="Button1"
           Text="Validate" 
           OnClick="ValidateBtn_OnClick" 
           runat="server"/>

   </form>
  
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="True" %>

<html>
<head>

   <script runat="server">

      void ValidateBtn_OnClick(object sender, EventArgs e) 
      { 

         // Display whether the page passed validation.
         if (Page.IsValid) 
         {

            Message.Text = "Page is valid.";

         }

         else 
         {

            Message.Text = "Page is not valid!";

         }

      }

      void ServerValidation(object source, ServerValidateEventArgs args)
      {

         try 
         {

            // Test whether the value entered into the text box is even.
            int i = int.Parse(args.Value);
            args.IsValid = ((i%2) == 0);

         }

         catch(Exception ex)
         {

            args.IsValid = false;

         }

      }

   </script>    

</head>
<body>

   <form runat="server">
  
      <h3>CustomValidator ServerValidate Example</h3>

      <asp:Label id="Message"  
           Text="Enter an even number:" 
           Font-Name="Verdana" 
           Font-Size="10pt" 
           runat="server"/>

      <p>

      <asp:TextBox id="Text1" 
           runat="server" />
    
      &nbsp;&nbsp;

      <asp:CustomValidator id="CustomValidator1"
           ControlToValidate="Text1"
           Display="Static"
           ErrorMessage="Not an even number!"
           ForeColor="green"
           Font-Name="verdana" 
           Font-Size="10pt"
           OnServerValidate="ServerValidation"
           runat="server"/>

      <p>
 
      <asp:Button id="Button1"
           Text="Validate" 
           OnClick="ValidateBtn_OnClick" 
           runat="server"/>

   </form>
  
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True" %>

<html>
<head>

   <script runat="server">

      Sub ValidateBtn_OnClick(sender As Object, e As EventArgs) 

         ' Display whether the page passed validation.
         If Page.IsValid Then 

            Message.Text = "Page is valid."

         Else 

            Message.Text = "Page is not valid!"

         End If

      End Sub

      Sub ServerValidation(source As Object, args As ServerValidateEventArgs)

         Try 

            ' Test whether the value entered into the text box is even.
            Dim num As Integer = Integer.Parse(args.Value)
            args.IsValid = ((num mod 2) = 0)
 
         Catch ex As Exception
         
            args.IsValid = false

         End Try

      End Sub

      Sub Page_Load(sende As object, e As EventArgs)

         ' Manually register the event-handling method for the  
         ' ServerValidate event of the CustomValidator control.
         AddHandler CustomValidator1.ServerValidate, _
             AddressOf ServerValidation

      End Sub

   </script>    

</head>
<body>

   <form runat="server">
  
      <h3>CustomValidator ServerValidate Example</h3>

      <asp:Label id="Message"
           Text="Enter an even number:" 
           Font-Name="Verdana" 
           Font-Size="10pt" 
           runat="server" />

      <p>

      <asp:TextBox id="Text1" 
           runat="server" />
    
      &nbsp;&nbsp;

      <asp:CustomValidator id="CustomValidator1"
           ControlToValidate="Text1"
           Display="Static"
           ErrorMessage="Not an even number!"
           ForeColor="green"
           Font-Name="verdana" 
           Font-Size="10pt"
           runat="server"/>

      <p>
 
      <asp:Button id="Button1"
           Text="Validate" 
           OnClick="ValidateBtn_OnClick" 
           runat="server"/>

   </form>
  
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="True" %>

<html>
<head>

   <script runat="server">

      void ValidateBtn_OnClick(object sender, EventArgs e) 
      { 

         // Display whether the page passed validation.
         if (Page.IsValid) 
         {

            Message.Text = "Page is valid.";

         }

         else 
         {

            Message.Text = "Page is not valid!";

         }

      }

      void ServerValidation(object source, ServerValidateEventArgs args)
      {

         try 
         {

            // Test whether the value entered into the text box is even.
            int i = int.Parse(args.Value);
            args.IsValid = ((i%2) == 0);

         }

         catch(Exception ex)
         {

            args.IsValid = false;

         }

      }

      void Page_Load(object sender, EventArgs e)
      {

         // Manually register the event-handling method for the  
         // ServerValidate event of the CustomValidator control.
         CustomValidator1.ServerValidate += 
             new ServerValidateEventHandler(this.ServerValidation);

      }

   </script>    

</head>
<body>

   <form runat="server">
  
      <h3>CustomValidator ServerValidate Example</h3>

      <asp:Label id="Message"  
           Text="Enter an even number:" 
           Font-Name="Verdana" 
           Font-Size="10pt" 
           runat="server"/>

      <p>

      <asp:TextBox id="Text1" 
           runat="server" />
    
      &nbsp;&nbsp;

      <asp:CustomValidator id="CustomValidator1"
           ControlToValidate="Text1"
           Display="Static"
           ErrorMessage="Not an even number!"
           ForeColor="green"
           Font-Name="verdana" 
           Font-Size="10pt"
           runat="server"/>

      <p>
 
      <asp:Button id="Button1"
           Text="Validate" 
           OnClick="ValidateBtn_OnClick" 
           runat="server"/>

   </form>
  
</body>
</html>

平台

Windows 98、Windows 2000 SP4、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表,请参见系统要求

版本信息

.NET Framework

受以下版本支持:2.0、1.1、1.0

请参见

参考

System.Web.UI.WebControls 命名空间
CustomValidator 类