Registers an event reference for validation with a unique control ID representing the client control generating the event.
Public Sub RegisterForEventValidation ( _ uniqueId As String _ )
Dim instance As ClientScriptManager Dim uniqueId As String instance.RegisterForEventValidation(uniqueId)
public void RegisterForEventValidation( string uniqueId )
public: void RegisterForEventValidation( String^ uniqueId )
public function RegisterForEventValidation( uniqueId : String )
The following code example demonstrates using the RegisterForEventValidation method and the ValidateEvent method to register a callback for validation and to validate that the callback originated from the page.
<%@ Page Language="VB" %> <%@ Implements Interface="System.Web.UI.ICallbackEventHandler" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Dim _cbMessage As String = "" ' Define method that processes the callbacks on server. Public Sub RaiseCallbackEvent(ByVal eventArgument As String) _ Implements System.Web.UI.ICallbackEventHandler.RaiseCallbackEvent Try Page.ClientScript.ValidateEvent(button1.UniqueID) _cbMessage = "Correct event raised callback." Catch ex As Exception _cbMessage = "Incorrect event raised callback." End Try End Sub ' Define method that returns callback result. Public Function GetCallbackResult() _ As String Implements _ System.Web.UI.ICallbackEventHandler.GetCallbackResult Return _cbMessage End Function Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) If (Not IsPostBack) Then Dim cs As ClientScriptManager = Page.ClientScript Dim cbReference As String = cs.GetCallbackEventReference("'" & _ Page.UniqueID & "'", "arg", "ReceiveServerData", "", _ "ProcessCallBackError", False) Dim callbackScript As String = "function CallTheServer(arg, context) {" & _ cbReference & "; }" cs.RegisterClientScriptBlock(Me.GetType(), "CallTheServer", _ callbackScript, True) End If End Sub Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter) Page.ClientScript.RegisterForEventValidation(button1.UniqueID) MyBase.Render(writer) End Sub </script> <script type="text/javascript"> var value1 = new Date(); function ReceiveServerData(arg, context) { Message.innerText = arg; Label1.innerText = "Callback completed at " + value1; value1 = new Date(); } function ProcessCallBackError(arg, context) { Message.innerText = 'An error has occurred.'; } </script> <html > <head runat="server"> <title>CallBack Event Validation Example</title> </head> <body> <form id="Form1" runat="server"> <div> Callback result: <span id="Message"></span> <br /> <br /> <input type="button" id="button1" runat="server" value="ClientCallBack" onclick="CallTheServer(value1, null )"/> <br /> <br /> <asp:Label id="Label1" runat="server"/> </div> </form> </body> </html>
<%@ Page Language="C#" %> <%@ Implements Interface="System.Web.UI.ICallbackEventHandler" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server" > string _cbMessage = ""; // Define method that processes the callbacks on server. public void RaiseCallbackEvent(String eventArgument) { try { Page.ClientScript.ValidateEvent(button1.UniqueID); _cbMessage = "Correct event raised callback."; } catch (Exception ex) { _cbMessage = "Incorrect event raised callback."; } } // Define method that returns callback result. public string GetCallbackResult() { return _cbMessage; } protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { ClientScriptManager cs = Page.ClientScript; String cbReference = cs.GetCallbackEventReference("'" + Page.UniqueID + "'", "arg", "ReceiveServerData", "", "ProcessCallBackError", false); String callbackScript = "function CallTheServer(arg, context) {" + cbReference + "; }"; cs.RegisterClientScriptBlock(this.GetType(), "CallTheServer", callbackScript, true); } } protected override void Render(HtmlTextWriter writer) { Page.ClientScript.RegisterForEventValidation(button1.UniqueID); base.Render(writer); } </script> <script type="text/javascript"> var value1 = new Date(); function ReceiveServerData(arg, context) { Message.innerText = arg; Label1.innerText = "Callback completed at " + value1; value1 = new Date(); } function ProcessCallBackError(arg, context) { Message.innerText = 'An error has occurred.'; } </script> <html > <head id="Head1" runat="server"> <title>CallBack Event Validation Example</title> </head> <body> <form id="Form1" runat="server"> <div> Callback result: <span id="Message"></span> <br /> <br /> <input type="button" id="button1" runat="server" value="ClientCallBack" onclick="CallTheServer(value1, null )"/> <br /> <br /> <asp:Label id="Label1" runat="server"/> </div> </form> </body> </html>
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
thanx for the illustration but can u give a fully functional example which i can either test or at least follow
Usage: When you want to manipulate some server controls using client side javascript.
Steps:
protected override void Render(HtmlTextWriter writer){Page.ClientScript.RegisterForEventValidation(DropDownList1.UniqueID);Page.ClientScript.RegisterForEventValidation(DropDownList2.UniqueID);
Page.ClientScript.RegisterForEventValidation(ListBox1.UniqueID);