DetailsViewModeEventHandler Delegat

  • Referenz

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Stellt die Methode dar, die das ModeChanging-Ereignis eines DetailsView-Steuerelements behandelt.

public delegate void DetailsViewModeEventHandler(System::Object ^ sender, DetailsViewModeEventArgs ^ e);
public delegate void DetailsViewModeEventHandler(object sender, DetailsViewModeEventArgs e);
type DetailsViewModeEventHandler = delegate of obj * DetailsViewModeEventArgs -> unit
Public Delegate Sub DetailsViewModeEventHandler(sender As Object, e As DetailsViewModeEventArgs)

Parameter

sender
Object

Die Quelle des Ereignisses.

e
DetailsViewModeEventArgs

Ein DetailsViewModeEventArgs, das die Ereignisdaten enthält.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie sie dem ModeChanging Ereignis eines Steuerelements programmgesteuert einen DetailsViewDetailsViewModeEventHandler Delegaten hinzufügen.


<%@ 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 Page_Load(Object sender, EventArgs e)
  {

    // Create a new DetailsView object.
    DetailsView customerDetailsView = new DetailsView();

    // Set the DetailsView object's properties.
    customerDetailsView.ID = "CustomerDetailsView";
    customerDetailsView.DataSourceID = "DetailsViewSource";
    customerDetailsView.AutoGenerateRows = true;
    customerDetailsView.AutoGenerateEditButton = true;
    customerDetailsView.AllowPaging = true;
    customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };

    // Programmatically register the event-handling method
    // for the ItemInserted event of a DetailsView control.
    customerDetailsView.ModeChanging += new DetailsViewModeEventHandler(this.CustomerDetailsView_ModeChanging);

    // Add the DetailsView object to the Controls collection
    // of the PlaceHolder control.
    DetailsViewPlaceHolder.Controls.Add(customerDetailsView);

  }
  
  void CustomerDetailsView_ModeChanging(Object sender, DetailsViewModeEventArgs e)
  {

    // Use the sender parameter to access the DetailsView
    // control that raised the event.
    DetailsView customerDetailsView = (DetailsView)sender;

    // Use the NewMode property to determine the mode to which the 
    // DetailsView control is transitioning.
    switch (e.NewMode)
    {
      case DetailsViewMode.Edit:
        // Hide the pager row and clear the Label control
        // when transitioning to edit mode.
        customerDetailsView.AllowPaging = false;
        MessageLabel.Text = "";
        break;
      case DetailsViewMode.ReadOnly:
        // Display the pager row and confirmation message
        // when transitioning to edit mode.
        customerDetailsView.AllowPaging = true;
        if (e.CancelingEdit)
        {
          MessageLabel.Text = "Update canceled.";
        }
        else
        {
          MessageLabel.Text = "Update completed.";
        }
        break;
      case DetailsViewMode.Insert:
        // Cancel the mode change if the DetailsView
        // control attempts to transition to insert 
        // mode.
        e.Cancel = true;
        break;
      default:
        MessageLabel.Text = "Unsupported mode.";
        break;
    }
    
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewModeEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewModeEventHandler Example</h3>
      
      <!-- Use a PlaceHolder control as the container for the -->
      <!-- dynamically generated DetailsView control.         -->       
      <asp:PlaceHolder id="DetailsViewPlaceHolder"
        runat="server"/>
        
      <br/><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 Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    ' Create a new DetailsView object.
    Dim customerDetailsView As New DetailsView()

    ' Set the DetailsView object's properties.
    customerDetailsView.ID = "CustomerDetailsView"
    customerDetailsView.DataSourceID = "DetailsViewSource"
    customerDetailsView.AutoGenerateRows = True
    customerDetailsView.AutoGenerateEditButton = True
    customerDetailsView.AllowPaging = True
    
    Dim keyArray() As String = {"CustomerID"}
    customerDetailsView.DataKeyNames = keyArray
    
    ' Programmatically register the event-handling method
    ' for the ItemInserted event of a DetailsView control.
    AddHandler customerDetailsView.ModeChanging, AddressOf CustomerDetailsView_ModeChanging

    ' Add the DetailsView object to the Controls collection
    ' of the PlaceHolder control.
    DetailsViewPlaceHolder.Controls.Add(customerDetailsView)

  End Sub
  
  Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs)

    ' Use the sender parameter to access the DetailsView
    ' control that raised the event.
    Dim customerDetailsView As DetailsView = CType(sender, DetailsView)

    ' Use the NewMode property to determine the mode to which the 
    ' DetailsView control is transitioning.
    Select Case e.NewMode
    
      Case DetailsViewMode.Edit
        ' Hide the pager row and clear the Label control
        ' when transitioning to edit mode.
        customerDetailsView.AllowPaging = False
        MessageLabel.Text = ""

      Case DetailsViewMode.ReadOnly
        ' Display the pager row and confirmation message
        ' when transitioning to edit mode.
        customerDetailsView.AllowPaging = True
        If e.CancelingEdit Then
        
          MessageLabel.Text = "Update canceled."
        
        Else
        
          MessageLabel.Text = "Update completed."
        
        End If

      Case DetailsViewMode.Insert
        ' Cancel the mode change if the DetailsView
        ' control attempts to transition to insert 
        ' mode.
        e.Cancel = True

      Case Else
        MessageLabel.Text = "Unsupported mode."
          
    End Select
    
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewModeEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewModeEventHandler Example</h3>
      
      <!-- Use a PlaceHolder control as the container for the -->
      <!-- dynamically generated DetailsView control.         -->       
      <asp:PlaceHolder id="DetailsViewPlaceHolder"
        runat="server"/>
        
      <br/><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>

Im folgenden Codebeispiel wird veranschaulicht, wie sie dem ModeChanging Ereignis eines Steuerelements deklarativ einen DetailsViewDetailsViewModeEventHandler Delegaten hinzufügen.


<%@ 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_ModeChanging(Object sender, DetailsViewModeEventArgs e)
  {

    // Use the NewMode property to determine the mode to which the 
    // DetailsView control is transitioning.
    switch (e.NewMode)
    {
      case DetailsViewMode.Edit:
        // Hide the pager row and clear the Label control
        // when transitioning to edit mode.
        CustomerDetailsView.AllowPaging = false;
        MessageLabel.Text = "";
        break;
      case DetailsViewMode.ReadOnly:
        // Display the pager row and confirmation message
        // when transitioning to edit mode.
        CustomerDetailsView.AllowPaging = true;
        if (e.CancelingEdit)
        {
          MessageLabel.Text = "Update canceled.";
        }
        else
        {
          MessageLabel.Text = "Update completed.";
        }
        break;
      case DetailsViewMode.Insert:
        // Cancel the mode change if the DetailsView
        // control attempts to transition to insert 
        // mode.
        e.Cancel = true;
        break;
      default:
        MessageLabel.Text = "Unsupported mode.";
        break;
    }
    
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewModeEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewModeEventHandler Example</h3>
                
      <asp:detailsview id="CustomerDetailsView"
        datasourceid="DetailsViewSource"
        datakeynames="CustomerID"
        autogeneraterows="true"
        autogenerateeditbutton="true" 
        allowpaging="true"
        onmodechanging="CustomerDetailsView_ModeChanging" 
        runat="server">

      </asp:detailsview>
      
      <br/><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" autoeventwireup="false" %>

<!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_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs) Handles CustomerDetailsView.ModeChanging

    ' Use the NewMode property to determine the mode to which the 
    ' DetailsView control is transitioning.
    Select Case e.NewMode
    
      Case DetailsViewMode.Edit
        ' Hide the pager row and clear the Label control
        ' when transitioning to edit mode.
        CustomerDetailsView.AllowPaging = False
        MessageLabel.Text = ""

      Case DetailsViewMode.ReadOnly
        ' Display the pager row and confirmation message
        ' when transitioning to edit mode.
        CustomerDetailsView.AllowPaging = True
        If e.CancelingEdit Then
        
          MessageLabel.Text = "Update canceled."
        
        Else
        
          MessageLabel.Text = "Update completed."
        
        End If

      Case DetailsViewMode.Insert
        ' Cancel the mode change if the DetailsView
        ' control attempts to transition to insert 
        ' mode.
        e.Cancel = True

      Case Else
        MessageLabel.Text = "Unsupported mode."
          
    End Select
    
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewModeEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewModeEventHandler Example</h3>
                
      <asp:detailsview id="CustomerDetailsView"
        datasourceid="DetailsViewSource"
        datakeynames="CustomerID"
        autogeneraterows="true"
        autogenerateeditbutton="true" 
        allowpaging="true"
        runat="server">

      </asp:detailsview>
      
      <br/><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 ModeChanging Ereignis wird ausgelöst, wenn ein DetailsView Steuerelement versucht, zwischen dem Bearbeitungs-, Einfüge- und schreibgeschützten Modus zu wechseln, aber bevor sich der Modus tatsächlich ändert. Dadurch können Sie einen Ereignishandler bereitstellen, der eine benutzerdefinierte Routine ausführt, z. B. das Konfigurieren des DetailsView Steuerelements für einen bestimmten Modus oder das Abbrechen der Modusänderung, wenn dieses Ereignis auftritt.

Beim Erstellen eines DetailsViewModeEventHandler-Delegaten bestimmen Sie die Methode für die Ereignisbehandlung. Um dem Ereignishandler das Ereignis zuzuordnen, fügen Sie dem Ereignis eine Instanz des Delegaten hinzu. Der Ereignishandler wird bei jedem Eintreten des Ereignisses aufgerufen, sofern der Delegat nicht entfernt wird. Weitere Informationen zu Ereignishandlerdelegierten finden Sie unter Behandeln und Auslösen von Ereignissen.

Erweiterungsmethoden

GetMethodInfo(Delegate)

Ruft ein Objekt ab, das die Methode darstellt, die vom angegebenen Delegaten dargestellt wird.

Gilt für:

Weitere Informationen