HiddenField.ValueChanged Event
Occurs when the value of the HiddenField control changes between posts to the server.
Assembly: System.Web (in System.Web.dll)
The ValueChanged event is raised when the value of the HiddenField control changes between posts to the server. This allows you to provide an event-handling method that performs a custom routine whenever this event occurs.
For more information about handling events, see NIB: Consuming Events.
The following example demonstrates how to use the ValueChanged event to display the value of the HiddenField control.
Security Note
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This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview. |
<%@ Page language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Sub ValueHiddenField_ValueChanged(ByVal sender As Object, ByVal e As EventArgs) ' Display the value of the HiddenField control. Message.Text = "The value of the HiddenField control is " & ValueHiddenField.Value & "." End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>HiddenField Example</title> </head> <body> <form id="Form1" runat="server"> <h3>HiddenField Example</h3> Please enter a value and click the submit button.<br/> <asp:textbox id="ValueTextBox" runat="server"/> <br/> <input type="submit" name="SubmitButton" value="Submit" onclick="PageLoad()" /> <br/> <asp:label id="Message" runat="server"/> <asp:hiddenfield id="ValueHiddenField" onvaluechanged="ValueHiddenField_ValueChanged" value="" runat="server"/> </form> </body> </html> <script type="text/javascript"> <!-- function PageLoad() { // Set the value of the HiddenField control with the // value from the TextBox. Form1.ValueHiddenField.value = Form1.ValueTextBox.value; } --> </script>
Available since 2.0
