ClientScriptManager.RegisterForEventValidation Metodo

Riferimento

Definizione

Spazio dei nomi:: System.Web.UI

Assembly:: System.Web.dll

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

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

InvalidOperationException

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

ValidateEvent(String)

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

ValidateEvent

Si applica a

ClientScriptManager.RegisterForEventValidation Metodo

Definizione

Overload

RegisterForEventValidation(String, String)

Parametri

Eccezioni

Esempio

Vedi anche

Si applica a

RegisterForEventValidation(String)

Parametri

Esempio

Commenti

Vedi anche

Si applica a

RegisterForEventValidation(PostBackOptions)

Parametri

Commenti

Vedi anche

Si applica a

Risorse aggiuntive