DetailsViewCommandEventHandler Delegat

  • Referenz

Definition

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

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

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

Parameter

sender
Object

Die Quelle des Ereignisses.

e
DetailsViewCommandEventArgs

Ein DetailsViewCommandEventArgs, das die Ereignisdaten enthält.

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie sie dem ItemCommand Ereignis eines Steuerelements programmgesteuert einen DetailsViewDetailsViewCommandEventHandler Delegaten hinzufügen. In diesem Beispiel wird das Codierungsmodell mit einer einzelnen Datei verwendet.


<%@ 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.AllowPaging = true;
    customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };

    // Add a button field to the DetailsView control.
    ButtonField field = new ButtonField();
    field.ButtonType = ButtonType.Link;
    field.CausesValidation = false;
    field.Text = "Add to List";
    field.CommandName="Add";

    customerDetailsView.Fields.Add(field);

    // Programmatically register the event-handling method
    // for the ItemDeleting event of a DetailsView control.
    customerDetailsView.ItemCommand 
      += new DetailsViewCommandEventHandler( 
      this.CustomerDetailsView_ItemCommand);

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

  }
  
  void CustomerDetailsView_ItemCommand(Object sender, 
    DetailsViewCommandEventArgs e)
  {

    // Use the CommandName property to determine which button
    // was clicked. 
    if (e.CommandName == "Add")
    {
      // Get the DetailsView control that raised the event.
      DetailsView customerDetailsView = (DetailsView)e.CommandSource;

      // Add the current customer to the customer list. 

      // Get the row that contains the company name. In this
      // example, the company name is in the second row (index 1)  
      // of the DetailsView control.
      DetailsViewRow row = customerDetailsView.Rows[1];

      // Get the company's name from the appropriate cell.
      // In this example, the company name is in the second cell  
      // (index 1) of the row.
      String name = row.Cells[1].Text;

      // Create a ListItem object with the company name.
      ListItem item = new ListItem(name);

      // Add the ListItem object to the ListBox, if the 
      // item doesn't already exist.
      if (!CustomerListBox.Items.Contains(item))
      {
        CustomerListBox.Items.Add(item);
      }

    }

  }
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewCommandEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>DetailsViewCommandEventHandler Example</h3>
      
      <!-- Use a PlaceHolder control as the container for the -->
      <!-- dynamically generated DetailsView control.         -->       
      <asp:placeholder id="DetailsViewPlaceHolder"
        runat="server"/>
      
      <br/><br/>
      
      Selected Customers:<br/>
      <asp:listbox id="CustomerListBox"
        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]"
        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.AllowPaging = True
    
    Dim keyArray() As String = {"CustomerID"}
    customerDetailsView.DataKeyNames = keyArray
    
    ' Add a button field to the DetailsView control.
    Dim field As New ButtonField()
    field.ButtonType = ButtonType.Link
    field.CausesValidation = False
    field.Text = "Add to List"
    field.CommandName = "Add"

    customerDetailsView.Fields.Add(field)

    ' Programmatically register the event-handling method
    ' for the ItemDeleting event of a DetailsView control.
    AddHandler customerDetailsView.ItemCommand, _
      AddressOf CustomerDetailsView_ItemCommand

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

  End Sub
  
  Sub CustomerDetailsView_ItemCommand(ByVal sender As Object, _
    ByVal e As DetailsViewCommandEventArgs)

    ' Use the CommandName property to determine which button
    ' was clicked. 
    If e.CommandName = "Add" Then

      ' Get the DetailsView control that raised the event.
      Dim customerDetailsView As DetailsView = _
        CType(e.CommandSource, DetailsView)

      ' Add the current customer to the customer list. 

      ' Get the row that contains the company name. In this
      ' example, the company name is in the second row (index 1)  
      ' of the DetailsView control.
      Dim row As DetailsViewRow = customerDetailsView.Rows(1)

      ' Get the company's name from the appropriate cell.
      ' In this example, the company name is in the second cell  
      ' (index 1) of the row.
      Dim name As String = row.Cells(1).Text

      ' Create a ListItem object with the company name.
      Dim item As New ListItem(name)

      ' Add the ListItem object to the ListBox, if the 
      ' item doesn't already exist.
      If Not CustomerListBox.Items.Contains(item) Then
      
        CustomerListBox.Items.Add(item)
        
      End If

    End If

  End Sub
  
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>DetailsViewCommandEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
    
      <h3>DetailsViewCommandEventHandler Example</h3>
      
      <!-- Use a PlaceHolder control as the container for the -->
      <!-- dynamically generated DetailsView control.         -->       
      <asp:placeholder id="DetailsViewPlaceHolder"
        runat="server"/>
      
      <br/><br/>
      
      Selected Customers:<br/>
      <asp:listbox id="CustomerListBox"
        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]"
        connectionstring=
            "<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>  
  
    </form>
  </body>
</html>

Das folgende Codebeispiel zeigt eine CodeBehind-Codemodellversion des vorherigen Beispiels. Damit dieses Beispiel funktioniert, müssen Sie den folgenden Code in die zugehörige CodeBehind-Datei kopieren.

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!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 runat="server">
    <title>DetailsViewCommandEventHandler Example</title>
</head>
<body>
    <form id="Form1" runat="server">
    
      <h3>DetailsViewCommandEventHandler Example</h3>
      
      <!-- Use a PlaceHolder control as the container for the -->
      <!-- dynamically generated DetailsView control.         -->       
      <asp:placeholder id="DetailsViewPlaceHolder"
        runat="server"/>
      
      <br/><br/>
      
      Selected Customers:<br/>
      <asp:listbox id="CustomerListBox"
        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]"
        connectionstring="
          <%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>  
  
    </form>
  </body>
</html>

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="DefaultVB.aspx.vb" Inherits="DefaultVB" %>

<!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 runat="server">
    <title>DetailsViewCommandEventHandler Example</title>
</head>
<body>
    <form id="Form1" runat="server">
    
      <h3>DetailsViewCommandEventHandler Example</h3>
      
      <!-- Use a PlaceHolder control as the container for the -->
      <!-- dynamically generated DetailsView control.         -->       
      <asp:placeholder id="DetailsViewPlaceHolder"
        runat="server"/>
      
      <br/><br/>
      
      Selected Customers:<br/>
      <asp:listbox id="CustomerListBox"
        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]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>  
  
    </form>
  </body>
</html>

Das folgende Codebeispiel zeigt die CodeBehind-Datei für das vorherige Beispiel.

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class _Default : System.Web.UI.Page 
{
    protected 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.AllowPaging = true;
        customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };

        // Add a button field to the DetailsView control.
        ButtonField field = new ButtonField();
        field.ButtonType = ButtonType.Link;
        field.CausesValidation = false;
        field.Text = "Add to List";
        field.CommandName = "Add";

        customerDetailsView.Fields.Add(field);

        // Programmatically register the event-handling method
        // for the ItemDeleting event of a DetailsView control.
        customerDetailsView.ItemCommand += new DetailsViewCommandEventHandler(this.CustomerDetailsView_ItemCommand);

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

    void CustomerDetailsView_ItemCommand(Object sender, DetailsViewCommandEventArgs e)
    {

        // Use the CommandName property to determine which button
        // was clicked. 
        if (e.CommandName == "Add")
        {
            // Get the DetailsView control that raised the event.
            DetailsView customerDetailsView = (DetailsView)sender;

            // Add the current customer to the customer list. 

            // Get the row that contains the company name. In this
            // example, the company name is in the second row (index 1)  
            // of the DetailsView control.
            DetailsViewRow row = customerDetailsView.Rows[1];

            // Get the company's name from the appropriate cell.
            // In this example, the company name is in the second cell  
            // (index 1) of the row.
            String name = row.Cells[1].Text;

            // Create a ListItem object with the company name.
            ListItem item = new ListItem(name);

            // Add the ListItem object to the ListBox, if the 
            // item doesn't already exist.
            if (!CustomerListBox.Items.Contains(item))
            {
                CustomerListBox.Items.Add(item);
            }
        }
    }
}

Partial Class DefaultVB
    Inherits System.Web.UI.Page

    Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load

        ' 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.AllowPaging = True

        Dim keyArray() As String = {"CustomerID"}
        customerDetailsView.DataKeyNames = keyArray

        ' Add a button field to the DetailsView control.
        Dim field As New ButtonField()
        field.ButtonType = ButtonType.Link
        field.CausesValidation = False
        field.Text = "Add to List"
        field.CommandName = "Add"

        customerDetailsView.Fields.Add(field)

        ' Programmatically register the event-handling method
        ' for the ItemDeleting event of a DetailsView control.
        AddHandler customerDetailsView.ItemCommand, AddressOf CustomerDetailsView_ItemCommand

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

    End Sub

    Sub CustomerDetailsView_ItemCommand(ByVal sender As Object, ByVal e As DetailsViewCommandEventArgs)

        ' Use the CommandName property to determine which button
        ' was clicked. 
        If e.CommandName = "Add" Then

            ' Get the DetailsView control that raised the event.
            Dim customerDetailsView As DetailsView = CType(sender, DetailsView)

            ' Add the current customer to the customer list. 

            ' Get the row that contains the company name. In this
            ' example, the company name is in the second row (index 1)  
            ' of the DetailsView control.
            Dim row As DetailsViewRow = customerDetailsView.Rows(1)

            ' Get the company's name from the appropriate cell.
            ' In this example, the company name is in the second cell  
            ' (index 1) of the row.
            Dim name As String = row.Cells(1).Text

            ' Create a ListItem object with the company name.
            Dim item As New ListItem(name)

            ' Add the ListItem object to the ListBox, if the 
            ' item doesn't already exist.
            If Not CustomerListBox.Items.Contains(item) Then

                CustomerListBox.Items.Add(item)

            End If

        End If

    End Sub

End Class

Im folgenden Codebeispiel wird veranschaulicht, wie sie dem ItemCommand Ereignis eines Steuerelements deklarativ einen DetailsViewDetailsViewCommandEventHandler 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 CustomerDetailView_ItemCommand(Object sender, DetailsViewCommandEventArgs e)
    {

        // Use the CommandName property to determine which button
        // was clicked. 
        if (e.CommandName == "Add")
        {

            // Add the current store to the contact list. 

            // Get the row that contains the store name. In this
            // example, the store name is in the second row (index 1)  
            // of the DetailsView control.
            DetailsViewRow row = CustomerDetailView.Rows[1];

            // Get the store's name from the appropriate cell.
            // In this example, the store name is in the second cell  
            // (index 1) of the row.
            String name = row.Cells[1].Text;

            // Create a ListItem object with the store's name.
            ListItem item = new ListItem(name);

            // Add the ListItem object to the ListBox, if the 
            // item doesn't already exist.
            if (!ContactListBox.Items.Contains(item))
            {
                ContactListBox.Items.Add(item);
            }

        }

    }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>
            DetailsView ItemCommand Example</title>
</head>
<body>
    <form id="Form1" runat="server">
        <h3>
            DetailsView ItemCommand Example</h3>
        <asp:DetailsView ID="CustomerDetailView" 
            DataSourceID="DetailsViewSource"
            AutoGenerateRows="false" 
            DataKeyNames="CustomerID" 
            AllowPaging="true" 
            OnItemCommand="CustomerDetailView_ItemCommand"
            runat="server">
            
            <FieldHeaderStyle BackColor="Navy" ForeColor="White" />
            
            <Fields>
                <asp:BoundField DataField="CustomerID" HeaderText="Store ID" />
                <asp:BoundField DataField="CompanyName" HeaderText="Store Name" />
                <asp:BoundField DataField="City" HeaderText="City" />
                <asp:ButtonField CommandName="Add" Text="Add Contact" />
            </Fields>
        </asp:DetailsView>
        
        <hr />
        
        Contacts:<br />
        <asp:ListBox ID="ContactListBox" 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" runat="server" 
          ConnectionString=
            "<%$ ConnectionStrings:NorthWindConnectionString%>"
            InsertCommand="INSERT INTO [Customers]([CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country]) VALUES (@CustomerID, @CompanyName, @Address, @City, @PostalCode, @Country)"
          SelectCommand="Select [CustomerID], [CompanyName], 
            [Address], [City], [PostalCode], [Country] From 
            [Customers]">
        </asp:SqlDataSource>
    </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 CustomerDetailView_ItemCommand(ByVal sender As Object, ByVal e As DetailsViewCommandEventArgs)
    
        ' Use the CommandName property to determine which button
        ' was clicked. 
        If e.CommandName = "Add" Then

            ' Add the current store to the contact list. 
     
            ' Get the row that contains the store name. In this
            ' example, the store name is in the second row (index 1)  
            ' of the DetailsView control.
            Dim row As DetailsViewRow = CustomerDetailView.Rows(1)
      
            ' Get the store's name from the appropriate cell.
            ' In this example, the store name is in the second cell  
            ' (index 1) of the row.
            Dim name As String = row.Cells(1).Text

            ' Create a ListItem object with the store's name.
            Dim item As New ListItem(name)

            ' Add the ListItem object to the ListBox, if the 
            ' item doesn't already exist.
            If Not ContactListBox.Items.Contains(item) Then
      
                ContactListBox.Items.Add(item)
      
            End If
        
        End If
    
    End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>
            DetailsView ItemCommand Example</title>
</head>
<body>
    <form id="Form1" runat="server">
        <h3>
            DetailsView ItemCommand Example</h3>
        <asp:DetailsView ID="CustomerDetailView" 
            DataSourceID="DetailsViewSource"
            AutoGenerateRows="false" 
            DataKeyNames="CustomerID" 
            AllowPaging="true" 
            OnItemCommand="CustomerDetailView_ItemCommand"
            runat="server">
            
            <FieldHeaderStyle BackColor="Navy" ForeColor="White" />
            
            <Fields>
                <asp:BoundField DataField="CustomerID" HeaderText="Store ID" />
                <asp:BoundField DataField="CompanyName" HeaderText="Store Name" />
                <asp:BoundField DataField="City" HeaderText="City" />
                <asp:ButtonField CommandName="Add" Text="Add Contact" />
            </Fields>
        </asp:DetailsView>
        
        <hr />
        
        Contacts:<br />
        <asp:ListBox ID="ContactListBox" 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" runat="server" 
          ConnectionString=
            "<%$ ConnectionStrings:NorthWindConnectionString%>"
            InsertCommand="INSERT INTO [Customers]([CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country]) VALUES (@CustomerID, @CompanyName, @Address, @City, @PostalCode, @Country)"
          SelectCommand="Select [CustomerID], [CompanyName], 
            [Address], [City], [PostalCode], [Country] From 
            [Customers]">
        </asp:SqlDataSource>
    </form>
</body>
</html>

Hinweise

Das DetailsView -Steuerelement löst das ItemCommand -Ereignis aus, wenn auf eine Schaltfläche innerhalb eines Zeilenfelds ButtonField, CommandFieldoder TemplateField geklickt wird. Dadurch können Sie einen Ereignishandler bereitstellen, der bei jedem Auftreten dieses Ereignisses eine benutzerdefinierte Routine ausführt.

Hinweis

Das DetailsView Steuerelement löst auch andere spezielle Ereignisse aus, wenn auf bestimmte Schaltflächen geklickt wird (Schaltflächen, deren CommandName Eigenschaft auf "Löschen", "Einfügen", "Seite" oder "Aktualisieren" festgelegt ist). Wenn Sie eine dieser Schaltflächen verwenden, sollten Sie eines der speziellen Ereignisse verwenden, die vom Steuerelement bereitgestellt werden (z ItemDeleted . B. oder ItemDeleting).

Beim Erstellen eines DetailsViewCommandEventHandler-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 Ereignishandlerdelegaten 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