DetailsViewUpdateEventArgs DetailsViewUpdateEventArgs DetailsViewUpdateEventArgs DetailsViewUpdateEventArgs Class

Definition

Stellt Daten für das ItemUpdating-Ereignis bereit.Provides data for the ItemUpdating event.

public ref class DetailsViewUpdateEventArgs : System::ComponentModel::CancelEventArgs
public class DetailsViewUpdateEventArgs : System.ComponentModel.CancelEventArgs
type DetailsViewUpdateEventArgs = class
    inherit CancelEventArgs
Public Class DetailsViewUpdateEventArgs
Inherits CancelEventArgs
Vererbung
DetailsViewUpdateEventArgsDetailsViewUpdateEventArgsDetailsViewUpdateEventArgsDetailsViewUpdateEventArgs

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie das DetailsViewUpdateEventArgs -Objekt verwendet wird, das an den ItemUpdating Ereignishandler für das-Ereignis übermittelt wird, um die vom Benutzer eingegebenen Werte zu überprüfenThe following code example demonstrates how to use the DetailsViewUpdateEventArgs object passed to the event handler for the ItemUpdating event to validate the values entered by the user.


<%@ Page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  
    void CustomerDetailsView_ItemUpdating(Object sender, 
      DetailsViewUpdateEventArgs e)
    {

        // Validate the field values entered by the user. This
        // example determines whether the user left any fields
        // empty. Use the NewValues property to access the new 
        // values entered by the user.
        ArrayList emptyFieldList = 
          ValidateFields((IOrderedDictionary)e.NewValues);

        if (emptyFieldList.Count > 0)
        {

            // The user left some fields empty. 
            // Display an error message.

            // Use the Keys property to retrieve the key field value.
            String keyValue = e.Keys["CustomerID"].ToString();

            MessageLabel.Text = 
              "You must enter a value for all fields of record " +
              keyValue + ".<br/>The following fields are missing:<br/><br/>";

            // Display the missing fields.
            foreach (String value in emptyFieldList)
            {
                // Use the OldValues property access the original
                // value of a field.
                MessageLabel.Text += value + " - Original Value = " +
                  e.OldValues[value].ToString() + "<br />";
            }

            // Cancel the update operation.
            e.Cancel = true;

        }
        else
        {
            // The field values passed validation. Clear the
            // error message label.
            MessageLabel.Text = "";
        }

    }

    ArrayList ValidateFields(IOrderedDictionary list)
    {

        // Create an ArrayList object to store the
        // names of any empty fields.
        ArrayList emptyFieldList = new ArrayList();

        // Iterate though the field values entered by
        // the user and check for an empty field. Empty
        // fields contain a null value.
        foreach (DictionaryEntry entry in list)
        {
            if (entry.Value == null)
            {
                // Add the field name to the ArrayList object.
                emptyFieldList.Add(entry.Key.ToString());
            }
        }

        return emptyFieldList;
    }

    void CustomerDetailsView_ModeChanging(Object sender, 
      DetailsViewModeEventArgs e)
    {
        if (e.CancelingEdit)
        {
            // The user canceled the update operation.
            // Clear the error message label.
            MessageLabel.Text = "";
        }
    }

</script>

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

  <head runat="server">
    <title>DetailsViewUpdateEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewUpdateEventArgs Example</h3>
                       
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          autogenerateeditbutton="true"  
          allowpaging="true"
          datakeynames="CustomerID" 
          onitemupdating="CustomerDetailsView_ItemUpdating"
          onmodechanging="CustomerDetailsView_ModeChanging" 
          runat="server">
            
          <pagersettings position="Bottom"/> 
                    
        </asp:detailsview>
        
        <br/>
        
        <asp:label id="MessageLabel"
          forecolor="Red"
          runat="server"/>
            
        <!-- This example uses Microsoft SQL Server and connects  -->
        <!-- to the Northwind sample database. Use an ASP.NET     -->
        <!-- expression to retrieve the connection string value   -->
        <!-- from the web.config file.                            -->
        <asp:sqldatasource id="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], 
            [City], [PostalCode], [Country] From [Customers]"
          updatecommand="Update [Customers] Set 
          [CompanyName]=@CompanyName, [Address]=@Address, 
          [City]=@City, [PostalCode]=@PostalCode, 
          [Country]=@Country 
          Where [CustomerID]=@CustomerID"
          connectionstring=
          "<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>


<%@ 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 CustomerDetailsView_ItemUpdating(ByVal sender As Object, _
    ByVal e As DetailsViewUpdateEventArgs)

    ' Validate the field values entered by the user. This
    ' example determines whether the user left any fields
    ' empty. Use the NewValues property to access the new 
    ' values entered by the user.
    Dim emptyFieldList As ArrayList = _
      ValidateFields(CType(e.NewValues, IOrderedDictionary))

    If emptyFieldList.Count > 0 Then

      ' The user left some fields empty. Display an error message.
      
      ' Use the Keys property to retrieve the key field value.
      Dim keyValue As String = e.Keys("CustomerID").ToString()

      MessageLabel.Text = _
        "You must enter a value for all fields of record " & _
        keyValue & ".<br/>The following fields are missing:<br/><br/>"

      ' Display the missing fields.
      Dim value As String
      For Each value In emptyFieldList
      
        ' Use the OldValues property access the original value
        ' of a field.
        MessageLabel.Text &= value & " - Original Value = " & _
          e.OldValues(value).ToString() & "<br />"
        
      Next

      ' Cancel the update operation.
      e.Cancel = True

    Else
    
      ' The field values passed validation. Clear the
      ' error message label.
      MessageLabel.Text = ""
      
    End If

  End Sub

    Function ValidateFields(ByVal list As IOrderedDictionary) _
      As ArrayList
    
        ' Create an ArrayList object to store the
        ' names of any empty fields.
        Dim emptyFieldList As New ArrayList()

        ' Iterate though the field values entered by
        ' the user and check for an empty field. Empty
        ' fields contain a null value.
        Dim entry As DictionaryEntry
    
        For Each entry In list
    
            If entry.Value Is Nothing Then
      
                ' Add the field name to the ArrayList object.
                emptyFieldList.Add(entry.Key.ToString())
        
            End If
        Next

        Return emptyFieldList
  
    End Function

  Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs)
  
    If e.CancelingEdit Then
      
      ' The user canceled the update operation.
      ' Clear the error message label.
      MessageLabel.Text = ""
    
    End If
    
  End Sub

</script>

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

  <head runat="server">
    <title>DetailsViewUpdateEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewUpdateEventArgs Example</h3>
                       
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          autogenerateeditbutton="true"  
          allowpaging="true"
          datakeynames="CustomerID" 
          onitemupdating="CustomerDetailsView_ItemUpdating"
          onmodechanging="CustomerDetailsView_ModeChanging" 
          runat="server">
            
          <pagersettings position="Bottom"/> 
                    
        </asp:detailsview>
        
        <br/>
        
        <asp:label id="MessageLabel"
          forecolor="Red"
          runat="server"/>
            
        <!-- This example uses Microsoft SQL Server and connects  -->
        <!-- to the Northwind sample database. Use an ASP.NET     -->
        <!-- expression to retrieve the connection string value   -->
        <!-- from the web.config file.                            -->
        <asp:sqldatasource id="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], 
          [City], [PostalCode], [Country] From [Customers]"
          updatecommand="Update [Customers] Set 
          [CompanyName]=@CompanyName, [Address]=@Address, 
          [City]=@City, [PostalCode]=@PostalCode, 
          [Country]=@Country 
          Where [CustomerID]=@CustomerID"
          connectionstring=
          "<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>

Hinweise

Das DetailsView -Steuerelement ItemUpdating löst das-Ereignis aus, DetailsView wenn auf eine Aktualisierungs Schaltfläche (eine Schaltfläche, deren CommandName -Eigenschaft auf "Update" festgelegt ist) im-Steuerelement geklickt wirdThe DetailsView control raises the ItemUpdating event when an Update button (a button with its CommandName property set to "Update") within the control is clicked, but before the DetailsView control updates the record. Dies ermöglicht es Ihnen, einen Ereignishandler bereitzustellen, der eine benutzerdefinierte Routine ausführt, z. b. die HTML-Codierung der Werte eines Datensatzes, bevor er in der Datenquelle aktualisiert wird, wenn dieses Ereignis auftritt.This allows you to provide an event handler that performs a custom routine, such as HTML-encoding the values of a record before updating it in the data source, whenever this event occurs.

Ein DetailsViewUpdateEventArgs -Objekt wird an den-Ereignishandler übermittelt, der es Ihnen ermöglicht, den Wert eines optionalen Befehls Arguments, DetailsView das an das Steuerelement gesendet wird, zu bestimmen und anzugeben, ob der Aktualisierungs Vorgang abgebrochen werden soll.A DetailsViewUpdateEventArgs object is passed to the event handler, which allows you to determine the value of an optional command argument sent to the DetailsView control and to indicate whether the update operation should be canceled. Verwenden Sie die CommandArgument -Eigenschaft, um den Wert des Befehls Arguments zu ermitteln.To determine the value of the command argument, use the CommandArgument property. Um den Aktualisierungs Vorgang abzubrechen, Cancel legen Sie truedie-Eigenschaft auf fest.To cancel the update operation, set the Cancel property to true. Mithilfe der Keys -Eigenschaft und der- NewValues Eigenschaft können Sie auch die neuen Werte lesen oder ändern, die vom Benutzer eingegeben wurden.You can also read or modify the new values entered by the user by using the Keys and NewValues properties. Die Keys -Eigenschaft enthält die Schlüsselfelder, während NewValues die-Eigenschaft die nicht Schlüsselfelder enthält.The Keys property contains the key fields, while the NewValues property contains the non-key fields. Wenn Sie auf die ursprünglichen nicht-Schlüssel Feldwerte zugreifen müssen, verwenden Sie OldValues die-Eigenschaft.If you need to access the original non-key field values, use the OldValues property.

Weitere Informationen zum Behandeln von Ereignissen finden Sie unter behandeln und Auslösen von Ereignissen.For more information about how to handle events, see Handling and Raising Events.

Eine Liste der anfänglichen Eigenschaftenwerte für eine Instanz der DetailsViewUpdateEventArgs-Klasse finden Sie im DetailsViewUpdateEventArgs-Konstruktor.For a list of initial property values for an instance of the DetailsViewUpdateEventArgs class, see the DetailsViewUpdateEventArgs constructor.

Konstruktoren

DetailsViewUpdateEventArgs(Object) DetailsViewUpdateEventArgs(Object) DetailsViewUpdateEventArgs(Object) DetailsViewUpdateEventArgs(Object)

Initialisiert eine neue Instanz der DetailsViewUpdateEventArgs-Klasse.Initializes a new instance of the DetailsViewUpdateEventArgs class.

Eigenschaften

Cancel Cancel Cancel Cancel

Ruft einen Wert ab, der angibt, ob das Ereignis abgebrochen werden soll, oder legt diesen fest.Gets or sets a value indicating whether the event should be canceled.

(Inherited from CancelEventArgs)
CommandArgument CommandArgument CommandArgument CommandArgument

Ruft das Befehlsargument für den an das DetailsView-Steuerelement übergebenen Aktualisierungsvorgang ab.Gets the command argument for the update operation passed to the DetailsView control.

Keys Keys Keys Keys

Ruft ein Wörterbuch ab, das die Name-Wert-Paare der Schlüsselfelder für den zu aktualisierenden Datensatz enthält.Gets a dictionary that contains the key field name/value pairs for the record to update.

NewValues NewValues NewValues NewValues

Ruft ein Wörterbuch ab, das die neuen Name-Wert-Paare der Felder für den zu aktualisierenden Datensatz enthält.Gets a dictionary that contains the new field name/value pairs for the record to update.

OldValues OldValues OldValues OldValues

Ruft ein Wörterbuch ab, das die Name-Wert-Paare des ursprünglichen Felds für den zu aktualisierenden Datensatz enthält.Gets a dictionary that contains the original field name/value pairs for the record to update.

Methoden

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Bestimmt, ob das angegebene Objekt mit dem aktuellen Objekt identisch ist.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Fungiert als Standardhashfunktion.Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Ruft den Type der aktuellen Instanz ab.Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Erstellt eine flache Kopie des aktuellen Object.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Gibt eine Zeichenfolge zurück, die das aktuelle Objekt darstellt.Returns a string that represents the current object.

(Inherited from Object)

Gilt für:

Siehe auch