ClientScriptManager.ValidateEvent Metodo

  • Riferimento

Definizione

Spazio dei nomi:
System.Web.UI
Assembly:
System.Web.dll

Convalida un evento client.

Overload

ValidateEvent(String)

Convalida un evento client registrato per la convalida degli eventi utilizzando il metodo RegisterForEventValidation(String).
ValidateEvent(String, String)

Convalida un evento client registrato per la convalida degli eventi utilizzando il metodo RegisterForEventValidation(String, String).

ValidateEvent(String)

Convalida un evento client registrato per la convalida degli eventi utilizzando il metodo RegisterForEventValidation(String).

public:
 void ValidateEvent(System::String ^ uniqueId);
public void ValidateEvent (string uniqueId);
member this.ValidateEvent : string -> unit
Public Sub ValidateEvent (uniqueId As String)

Parametri

uniqueId
String

ID univoco che rappresenta il controllo client che genera l'evento.

Vedi anche

Si applica a

ValidateEvent(String, String)

Convalida un evento client registrato per la convalida degli eventi utilizzando il metodo RegisterForEventValidation(String, String).

public:
 void ValidateEvent(System::String ^ uniqueId, System::String ^ argument);
public void ValidateEvent (string uniqueId, string argument);
member this.ValidateEvent : string * string -> unit
Public Sub ValidateEvent (uniqueId As String, argument As String)

Parametri

uniqueId
String

ID univoco che rappresenta il controllo client che genera l'evento.

argument
String

Argomenti di evento passati con l'evento client.

Eccezioni

ArgumentException

uniqueId è null o è una stringa vuota ("").

Esempio

Nell'esempio di codice seguente viene illustrato l'uso del RegisterForEventValidation metodo e del ValidateEvent metodo per registrare un callback per la convalida e per verificare che il callback abbia avuto origine dalla pagina. Per migliorare la convalida illustrata qui, è possibile modificare il parametro di convalida argument in modo da contenere informazioni specifiche per l'utente, ad esempio un'identità o un ruolo

<%@ 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, this.ToString());
            _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, this.ToString());
        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 xmlns="http://www.w3.org/1999/xhtml" >
<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="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, Me.ToString())
            _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, Me.ToString())
        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 xmlns="http://www.w3.org/1999/xhtml" >
<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>

Vedi anche

Si applica a