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CustomValidator.ServerValidate Event

Occurs when validation is performed on the server.

[Visual Basic]
Public Event ServerValidate As ServerValidateEventHandler
[C#]
public event ServerValidateEventHandler ServerValidate;
[C++]
public: __event ServerValidateEventHandler* ServerValidate;

[JScript] In JScript, you can handle the events defined by a class, but you cannot define your own.

Event Data

The event handler receives a string containing the text to validate.

Remarks

The ServerValidate event is raised when validation is performed on the server. This event is used to provide a custom validation routine for an input control, such as a TextBox control.

For more information about handling events, see Consuming Events.

Example

[Visual Basic, C#] The following example demonstrates how to specify and code a handler for a server-side CustomValidator control. It creates a custom validation routine, validates the value of a TextBox control for an even number, and then displays the result of the validation.

[Visual Basic] 

<%@ 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>


[C#] 

<%@ 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>


[Visual Basic] 

<%@ 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>


[C#] 

<%@ 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>

[C++, JScript] No example is available for C++ or JScript. To view a Visual Basic or C# example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family

See Also

CustomValidator Class | CustomValidator Members | System.Web.UI.WebControls Namespace | OnServerValidate | ServerValidateEventHandler

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