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ClientScriptManager.RegisterForEventValidation Metodo

Definizione

Registra un riferimento a un evento per la convalida.

Overload

RegisterForEventValidation(String, String)

Registra un riferimento a un evento per la convalida con un ID di controllo univoco e argomenti di evento che rappresentano il controllo client che genera l'evento.

RegisterForEventValidation(String)

Registra un riferimento a un evento per la convalida con un ID di controllo univoco che rappresenta il controllo client che genera l'evento.

RegisterForEventValidation(PostBackOptions)

Registra un riferimento a un evento per la convalida con PostBackOptions.

RegisterForEventValidation(String, String)

Registra un riferimento a un evento per la convalida con un ID di controllo univoco e argomenti di evento che rappresentano il controllo client che genera l'evento.

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

Il metodo viene chiamato prima del metodo Render(HtmlTextWriter).

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 nell'esempio, 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>

Nell'esempio di codice seguente viene illustrato l'uso del RegisterForEventValidation metodo per registrare un callback per la convalida.

<%@ Page EnableEventValidation="true" Language="C#"  %>
<!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 id="Head1" runat="server">
    <title>Register an option for event validation</title>
    <script runat="server">
        protected override void Render(HtmlTextWriter writer)
        {
            ClientScript.RegisterForEventValidation("DropDownList1", "This is Option 1");
            ClientScript.RegisterForEventValidation("DropDownList1", "This is Option 2");
            ClientScript.RegisterForEventValidation("DropDownList1", "This is Option 3");
            // Uncomment the line below when you want to specifically register the option for event validation.
            // ClientScript.RegisterForEventValidation("DropDownList1", "Is this option registered for event validation?");
            base.Render(writer);
        }
    </script>
    <script type="text/javascript">
        function Initialize()
        {
            var oOption = document.createElement("OPTION");
            document.all("DropDownList1").options.add(oOption);
            oOption.innerText = "This is Option 1";            
            oOption = document.createElement("OPTION");            
            document.all("DropDownList1").options.add(oOption);
            oOption.innerText = "This is Option 2";
            oOption = document.createElement("OPTION");                
            document.all("DropDownList1").options.add(oOption); 
            oOption.innerText = "This is Option 3";
            oOption = document.createElement("OPTION");                
            document.all("DropDownList1").options.add(oOption); 
            oOption.innerText = "Is this option registered for event validation?";
        }
    </script>
</head>
<body onload="Initialize();">
    <form id="form1" runat="server">
    <div>
        <asp:DropDownList ID="DropDownList1" runat="server"></asp:DropDownList>
        <asp:Button ID="Button1" runat="server" Text="Postback to server for validation" />
    </div>
    </form>
</body>
</html>
<%@ Page EnableEventValidation="true" Language="VB"  %>
<!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 id="Head1" runat="server">
    <title>Register an option for event validation</title>
    <script runat="server">
        Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)
            ClientScript.RegisterForEventValidation("DropDownList1", "This is Option 1")
            ClientScript.RegisterForEventValidation("DropDownList1", "This is Option 2")
            ClientScript.RegisterForEventValidation("DropDownList1", "This is Option 3")
            ' Uncomment the line below when you want to specifically register the option for event validation.
            ' ClientScript.RegisterForEventValidation("DropDownList1", "Is this option registered for event validation?")
            MyBase.Render(writer)
        End Sub
    </script>
    <script type="text/javascript">
        function Initialize()
        {
            var oOption = document.createElement("OPTION");
            document.all("DropDownList1").options.add(oOption);
            oOption.innerText = "This is Option 1";            
            oOption = document.createElement("OPTION");            
            document.all("DropDownList1").options.add(oOption);
            oOption.innerText = "This is Option 2";
            oOption = document.createElement("OPTION");                
            document.all("DropDownList1").options.add(oOption); 
            oOption.innerText = "This is Option 3";
            oOption = document.createElement("OPTION");                
            document.all("DropDownList1").options.add(oOption); 
            oOption.innerText = "Is this option registered for event validation?";
        }
    </script>
</head>
<body onload="Initialize();">
    <form id="form1" runat="server">
    <div>
        <asp:DropDownList ID="DropDownList1" runat="server">
        </asp:DropDownList>
        <asp:Button ID="Button1" runat="server" Text="Postback to server for validation" />
    </div>
    </form>
</body>
</html>

Vedi anche

Si applica a

RegisterForEventValidation(String)

Registra un riferimento a un evento per la convalida con un ID di controllo univoco che rappresenta il controllo client che genera l'evento.

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

Parametri

uniqueId
String

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

Esempio

Nell'esempio seguente viene illustrato come usare il RegisterForEventValidation metodo e il ValidateEvent metodo per registrare un callback per la convalida e come convalidare l'origine del callback dalla pagina.

<%@ 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 xmlns="http://www.w3.org/1999/xhtml" >
<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>
<%@ 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 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>

Commenti

Per altre informazioni ed esempi, vedere il RegisterForEventValidation metodo .

Vedi anche

Si applica a

RegisterForEventValidation(PostBackOptions)

Registra un riferimento a un evento per la convalida con PostBackOptions.

public:
 void RegisterForEventValidation(System::Web::UI::PostBackOptions ^ options);
public void RegisterForEventValidation (System.Web.UI.PostBackOptions options);
member this.RegisterForEventValidation : System.Web.UI.PostBackOptions -> unit
Public Sub RegisterForEventValidation (options As PostBackOptions)

Parametri

options
PostBackOptions

Oggetto PostBackOptions che specifica come viene generato uno script JavaScript client per avviare un evento di postback.

Commenti

Per altre informazioni ed esempi, vedere il RegisterForEventValidation metodo .

Vedi anche

Si applica a