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HtmlButton.CausesValidation Property

Gets or sets a value indicating whether validation is performed when the HtmlButton control is clicked.

Namespace:  System.Web.UI.HtmlControls
Assembly:  System.Web (in System.Web.dll)

public virtual bool CausesValidation { get; set; }
<asp:HtmlButton CausesValidation="True|False" />

Property Value

Type: System.Boolean
true if validation is performed when the HtmlButton control is clicked; otherwise, false. The default value is true.

By default, page validation is performed when an HtmlButton control is clicked. Page validation determines whether the input controls associated with a validation control on the page all pass the validation rules specified by the validation control.

You can specify or determine whether validation is performed on both the client and the server when an HtmlButton control is clicked by using the CausesValidation property. To prevent validation from being performed, set the CausesValidation property to false.

This property is commonly used in the event handler for the ServerClick event to prevent page validation from occurring when a Cancel or Reset button is clicked.

The following code example demonstrates how to use the CausesValidation property to prevent page validation from occurring. Note that the Validate method activates each validation control independently.


<%@ Page Language="C#" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" > 

<head>
    <title> HtmlButton CausesValidation Example </title>
<script runat="server">

      void SubmitButton_Click(Object sender, EventArgs e)
      {

         // Determine which button was clicked.
         switch(((HtmlButton)sender).ID)
         {

            case "CityQueryButton":

               // Validate only the controls used for the city query.
               CityReqValidator.Validate();

               // Take the appropriate action if the controls pass validation. 
               if (CityReqValidator.IsValid)
               {
                  Message.InnerHtml = "You have chosen to run a query for the following city: " + 
                     CityTextBox.Value;
               }

               break;

            case "StateQueryButton":

               // Validate only the controls used for the state query.
               StateReqValidator.Validate();

               // Take the appropriate action if the controls pass validation.
               if (StateReqValidator.IsValid)
               {
                  Message.InnerHtml = "You have chosen to run a query for the following state: " + 
                     StateTextBox.Value;
               }

               break;

            default:

               // If the button clicked is not recognized, erase the message on the page.
               Message.InnerHtml = "";

               break;

         }

      }

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3> HtmlButton CausesValidation Example </h3>

      <table border="1" cellpadding="10">
         <tr>
            <td>
               <b>Enter city to query.</b> <br />
               <input id="CityTextBox" 
                      type="Text"
                      runat="server"/>
               <asp:RequiredFieldValidator ID="CityReqValidator"
                    ControlToValidate="CityTextBox"
                    ErrorMessage="<br />Please enter a city."
                    Display="Dynamic"
                    EnableClientScript="False"
                    runat="server"/>
            </td>
            <td valign="bottom">
               <button id="CityQueryButton"
                       causesvalidation="False"
                       onserverclick="SubmitButton_Click"
                       runat="server">
                  Submit
               </button>
            </td>
         </tr>

         <tr>
            <td>
               <b>Enter state to query.</b> <br />
               <input id="StateTextBox" 
                      type="Text" 
                      runat="server"/>
               <asp:RequiredFieldValidator ID="StateReqValidator"
                    ControlToValidate="StateTextBox"
                    ErrorMessage="<br />Please enter a state."
                    Display="Dynamic"
                    EnableClientScript="False"
                    runat="server"/>
            </td>
            <td valign="bottom">
               <button id="StateQueryButton"
                       causesvalidation="False"
                       onserverclick="SubmitButton_Click"
                       runat="server">
                  Submit
               </button>
            </td>
         </tr>

      </table>

      <br /><br />

      <span id="Message"
            runat="Server"/>


   </form>

</body>
</html>

.NET Framework

Supported in: 4.6, 4, 3.5, 3.0, 2.0, 1.1, 1.0

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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