DataListCommandEventHandler Délégué

Définition

Représente la méthode qui gérera les événements CancelCommand, DeleteCommand, EditCommand, ItemCommand et UpdateCommand d'un contrôle DataList.Represents the method that will handle the CancelCommand, DeleteCommand, EditCommand, ItemCommand, and UpdateCommand events of a DataList control.

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

Paramètres

source
Object

Source de l'événement.The source of the event.

e
DataListCommandEventArgs

DataListCommandEventArgs qui contient les données d'événement.A DataListCommandEventArgs that contains the event data.

Héritage
DataListCommandEventHandler

Exemples

L’exemple suivant montre comment définir des gestionnaires d’événements pour les EditCommandévénements UpdateCommand CancelCommand , et DeleteCommand d’un DataList contrôle.The following example demonstrates how to define event handlers for the EditCommand, UpdateCommand, CancelCommand and DeleteCommand events of a DataList control. Cet exemple spécifie les gestionnaires d’événements de façon déclarative, en définissant le gestionnaire d’événements DataList pour chaque propriété de commande sur le contrôle.This example specifies the event handlers declaratively, setting the event handler for each command property on the DataList control.


<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!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>
    <title>DataList Edit Example</title>
<script runat="server">

      // The Cart and CartView objects temporarily store the data source
      // for the DataList control while the page is being processed.
      DataTable Cart = new DataTable();
      DataView CartView;   
 
      void Page_Load(Object sender, EventArgs e) 
      {
 
         // With a database, use an select query to retrieve the data. 
         // Because the data source in this example is an in-memory
         // DataTable, retrieve the data from session state if it exists;
         // otherwise, create the data source.
         GetSource();

         // The DataList control maintains state between posts to the server;
         // it only needs to be bound to a data source the first time the
         // page is loaded or when the data source is updated.
         if (!IsPostBack)
         {

            BindList();

         }
                   
      }

      void BindList() 
      {

         // Set the data source and bind to the DataList control.
         ItemsList.DataSource = CartView;
         ItemsList.DataBind();

      }

      void GetSource()
      {

         // For this example, the data source is a DataTable that 
         // is stored in session state. If the data source does not exist,
         // create it; otherwise, load the data.
         if (Session["ShoppingCart"] == null) 
         {     

            // Create the sample data.
            DataRow dr;  
 
            // Define the columns of the table.
            Cart.Columns.Add(new DataColumn("Qty", typeof(Int32)));
            Cart.Columns.Add(new DataColumn("Item", typeof(String)));
            Cart.Columns.Add(new DataColumn("Price", typeof(Double)));

            // Store the table in session state to persist its values 
            // between posts to the server.
            Session["ShoppingCart"] = Cart;
             
            // Populate the DataTable with sample data.
            for (int i = 1; i <= 9; i++) 
            {
               dr = Cart.NewRow();
               if (i % 2 != 0)
               {
                  dr[0] = 2;
               }
               else
               {
                  dr[0] = 1;
               }
               dr[1] = "Item " + i.ToString();
               dr[2] = (1.23 * (i + 1));
               Cart.Rows.Add(dr);
            }

         } 

         else
         {

            // Retrieve the sample data from session state.
            Cart = (DataTable)Session["ShoppingCart"];

         }         
 
         // Create a DataView and specify the field to sort by.
         CartView = new DataView(Cart);
         CartView.Sort="Item";

         return;

      }

      void Edit_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Set the EditItemIndex property to the index of the item clicked
         // in the DataList control to enable editing for that item. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = e.Item.ItemIndex;
         BindList();

      }

      void Cancel_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Set the EditItemIndex property to -1 to exit editing mode. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

      void Delete_Command(Object sender, DataListCommandEventArgs e) 
      { 

         // Retrieve the name of the item to remove.
         String item = ((Label)e.Item.FindControl("ItemLabel")).Text;

         // Filter the CartView for the selected item and remove it from
         // the data source.
         CartView.RowFilter = "Item='" + item + "'";
         if (CartView.Count > 0) 
         {
            CartView.Delete(0);
         }
         CartView.RowFilter = "";

         // Set the EditItemIndex property to -1 to exit editing mode. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

      void Update_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Retrieve the updated values from the selected item.
         String item = ((Label)e.Item.FindControl("ItemLabel")).Text;
         String qty = ((TextBox)e.Item.FindControl("QtyTextBox")).Text;
         String price = ((TextBox)e.Item.FindControl("PriceTextBox")).Text;

         // With a database, use an update command to update the data.
         // Because the data source in this example is an in-memory 
         // DataTable, delete the old row and replace it with a new one.

         // Filter the CartView for the selected item and remove it from
         // the data source.
         CartView.RowFilter = "Item='" + item + "'";
         if (CartView.Count > 0)
         {
            CartView.Delete(0);
         }
         CartView.RowFilter = "";

         // ***************************************************************
         // Insert data validation code here. Make sure to validate the
         // values entered by the user before converting to the appropriate
         // data types and updating the data source.
         // ***************************************************************

         // Add a new entry to replace the previous item.
         DataRow dr = Cart.NewRow();
         dr[0] = qty;
         dr[1] = item;
         // If necessary, remove the '$' character from the price before
         // converting the price to a Double.
         if(price[0] == '$')
         {
            dr[2] = Convert.ToDouble(price.Substring(1));
         }
         else
         {
            dr[2] = Convert.ToDouble(price);
         }
         Cart.Rows.Add(dr);

         // Set the EditItemIndex property to -1 to exit editing mode. 
         // Be sure to rebind the DataList to the data source to refresh
         // the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

   </script>

</head>
<body>

   <form id="form1" runat="server">

      <h3>DataList Edit Example</h3>

      Click <b>Edit</b> to edit the values of the item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           RepeatColumns="3"
           RepeatDirection="Horizontal"
           CellPadding="3"
           CellSpacing="0"
           OnEditCommand="Edit_Command"
           OnUpdateCommand="Update_Command"
           OnDeleteCommand="Delete_Command"
           OnCancelCommand="Cancel_Command"
           runat="server">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <EditItemStyle BackColor="yellow">
         </EditItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            Item:
            <%# DataBinder.Eval(Container.DataItem, "Item") %> 

            <br />

            Quantity:
            <%# DataBinder.Eval(Container.DataItem, "Qty") %>

            <br />

            Price:
            <%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>

            <br />

            <asp:LinkButton id="EditButton" 
                 Text="Edit" 
                 CommandName="Edit"
                 runat="server"/>

         </ItemTemplate>
              
         <EditItemTemplate>

            Item:
            <asp:Label id="ItemLabel" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>' 
                 runat="server"/>

            <br />

            Quantity:
            <asp:TextBox id="QtyTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>' 
                 runat="server"/>

            <br />

            Price:
            <asp:TextBox id="PriceTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>' 
                 runat="server"/>

            <br />

            <asp:LinkButton id="UpdateButton" 
                 Text="Update" 
                 CommandName="Update" 
                 runat="server"/>

            <asp:LinkButton id="DeleteButton" 
                 Text="Delete" 
                 CommandName="Delete" 
                 runat="server"/>

            <asp:LinkButton id="CancelButton" 
                 Text="Cancel" 
                 CommandName="Cancel" 
                 runat="server"/>

         </EditItemTemplate>

      </asp:DataList>

   </form>

</body>
</html>


<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!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>
    <title>DataList Edit Example</title>
<script runat="server">

      ' The Cart and CartView objects temporarily store the data source
      ' for the DataList control while the page is being processed.
      Dim Cart As DataTable = New DataTable()
      Dim CartView As DataView
 
      Sub Page_Load(sende As Object, e As EventArgs) 
 
         ' With a database, use an select query to retrieve the data.
         ' Because the data source in this example is an in-memory
         ' DataTable, retrieve the data from session state if it exists;
         ' otherwise, create the data source.
         GetSource()

         ' The DataGrid control maintains state between posts to the server;
         ' it only needs to be bound to a data source the first time the
         ' page is loaded or when the data source is updated.
         If Not IsPostBack Then

            BindList()

         End If
                   
      End Sub

      Sub BindList() 

         ' Set the data source and bind to the DataList control.
         ItemsList.DataSource = CartView
         ItemsList.DataBind()

      End Sub

      Sub GetSource()

         ' For this example, the data source is a DataTable that
         ' is stored in session state. If the data source does not exist,
         ' create it; otherwise, load the data.
         If Session("ShoppingCart") Is Nothing Then 

            ' Create the sample data.
            Dim dr As DataRow  
 
            ' Define the columns of the table.
            Cart.Columns.Add(new DataColumn("Qty", GetType(Int32)))
            Cart.Columns.Add(new DataColumn("Item", GetType(String)))
            Cart.Columns.Add(new DataColumn("Price", GetType(Double)))

            ' Store the table in session state to persist its values
            ' between posts to the server.
            Session("ShoppingCart") = Cart
             
            ' Populate the DataTable with sample data.
            Dim i As Integer

            For i = 1 To 9 
            
               dr = Cart.NewRow()
               If (i Mod 2) <> 0 Then

                  dr(0) = 2
               
               Else
               
                  dr(0) = 1
               
               End If

               dr(1) = "Item " & i.ToString()
               dr(2) = (1.23 * (i + 1))
               Cart.Rows.Add(dr)
            
            Next i

         Else

            ' Retrieve the sample data from session state.
            Cart = CType(Session("ShoppingCart"), DataTable)

         End If         
 
         ' Create a DataView and specify the field to sort by.
         CartView = New DataView(Cart)
         CartView.Sort="Item"

         Return

      End Sub

      Sub Edit_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Set the EditItemIndex property to the index of the item clicked
         ' in the DataList control to enable editing for that item. Be sure
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = e.Item.ItemIndex
         BindList()

      End Sub

      Sub Cancel_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Set the EditItemIndex property to -1 to exit editing mode. Be sure
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

      Sub Delete_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Retrieve the name of the item to remove.
         Dim item As String = (CType(e.Item.FindControl("ItemLabel"), Label)).Text

         ' Filter the CartView for the selected item and remove it from
         ' the data source.
         CartView.RowFilter = "Item='" & item & "'"
         If CartView.Count > 0 Then 
       
            CartView.Delete(0)
         
         End If
         CartView.RowFilter = ""

         ' Set the EditItemIndex property to -1 to exit editing mode. Be sure 
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

      Sub Update_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Retrieve the updated values from the selected item.
         Dim item As String = _
             (CType(e.Item.FindControl("ItemLabel"), Label)).Text
         Dim qty As String = _
             (CType(e.Item.FindControl("QtyTextBox"), TextBox)).Text
         Dim price As String = _
             (CType(e.Item.FindControl("PriceTextBox"), TextBox)).Text

         ' With a database, use an update command to update the data.
         ' Because the data source in this example is an in-memory 
         ' DataTable, delete the old row and replace it with a new one.

         ' Filter the CartView for the selected item and remove it from 
         ' the data source.
         CartView.RowFilter = "Item='" & item & "'"
         If CartView.Count > 0 Then 
       
            CartView.Delete(0)
         
         End If
         CartView.RowFilter = ""

         ' ***************************************************************
         ' Insert data validation code here. Make sure to validate the
         ' values entered by the user before converting to the appropriate
         ' data types and updating the data source.
         ' ***************************************************************

         ' Add a new entry to replace the previous item.
         Dim dr As DataRow = Cart.NewRow()
         dr(0) = qty
         dr(1) = item
         ' If necessary, remove the '$' character from the price before 
         ' converting the price to a Double.
         If price.Chars(0) = "$" Then

            dr(2) = Convert.ToDouble(price.Substring(1))

         Else

            dr(2) = Convert.ToDouble(price)
         
         End If

         Cart.Rows.Add(dr)

         ' Set the EditItemIndex property to -1 to exit editing mode. 
         ' Be sure to rebind the DataList to the data source to refresh 
         ' the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

   </script>

</head>
<body>

   <form id="form1" runat="server">

      <h3>DataList Edit Example</h3>

      Click <b>Edit</b> to edit the values of the item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           RepeatColumns="3"
           RepeatDirection="Horizontal"
           CellPadding="3"
           CellSpacing="0"
           OnEditCommand="Edit_Command"
           OnUpdateCommand="Update_Command"
           OnDeleteCommand="Delete_Command"
           OnCancelCommand="Cancel_Command"
           runat="server">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <EditItemStyle BackColor="yellow">
         </EditItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            Item:
            <%# DataBinder.Eval(Container.DataItem, "Item") %> 

            <br />

            Quantity:
            <%# DataBinder.Eval(Container.DataItem, "Qty") %>

            <br />

            Price:
            <%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>

            <br />

            <asp:LinkButton id="EditButton" 
                 Text="Edit" 
                 CommandName="Edit"
                 runat="server"/>

         </ItemTemplate>
              
         <EditItemTemplate>

            Item:
            <asp:Label id="ItemLabel" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>' 
                 runat="server"/>

            <br />

            Quantity:
            <asp:TextBox id="QtyTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>' 
                 runat="server"/>

            <br />

            Price:
            <asp:TextBox id="PriceTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>' 
                 runat="server"/>

            <br />

            <asp:LinkButton id="UpdateButton" 
                 Text="Update" 
                 CommandName="Update" 
                 runat="server"/>

            <asp:LinkButton id="DeleteButton" 
                 Text="Delete" 
                 CommandName="Delete" 
                 runat="server"/>

            <asp:LinkButton id="CancelButton" 
                 Text="Cancel" 
                 CommandName="Cancel" 
                 runat="server"/>

         </EditItemTemplate>

      </asp:DataList>

   </form>

</body>
</html>

L’exemple de code suivant montre comment spécifier les gestionnaires d’événements et les ajouter par programmation aux événements de la Page_Load méthode.The following code example demonstrates how to specify the event handlers and programmatically add them to the events in the Page_Load method.


<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!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>
    <title>DataList Edit Example</title>
<script runat="server">

      // The Cart and CartView objects temporarily store the data source
      // for the DataList control while the page is being processed.
      DataTable Cart = new DataTable();
      DataView CartView;   
 
      void Page_Load(Object sender, EventArgs e) 
      {
 
         // With a database, use an select query to retrieve the data. 
         // Because the data source in this example is an in-memory
         // DataTable, retrieve the data from session state if it exists;
         // otherwise, create the data source.
         GetSource();

         // The DataList control maintains state between posts to the server;
         // it only needs to be bound to a data source the first time the
         // page is loaded or when the data source is updated.
         if (!IsPostBack)
         {

            BindList();

         }

         // Manually register the event-handling methods.
         ItemsList.EditCommand += 
             new DataListCommandEventHandler(this.Edit_Command);
         ItemsList.UpdateCommand += 
             new DataListCommandEventHandler(this.Update_Command);
         ItemsList.DeleteCommand += 
             new DataListCommandEventHandler(this.Delete_Command);
         ItemsList.CancelCommand += 
             new DataListCommandEventHandler(this.Cancel_Command);
                   
      }

      void BindList() 
      {

         // Set the data source and bind to the DataList control.
         ItemsList.DataSource = CartView;
         ItemsList.DataBind();

      }

      void GetSource()
      {

         // For this example, the data source is a DataTable that 
         // is stored in session state. If the data source does not exist,
         // create it; otherwise, load the data.
         if (Session["ShoppingCart"] == null) 
         {     

            // Create the sample data.
            DataRow dr;  
 
            // Define the columns of the table.
            Cart.Columns.Add(new DataColumn("Qty", typeof(Int32)));
            Cart.Columns.Add(new DataColumn("Item", typeof(String)));
            Cart.Columns.Add(new DataColumn("Price", typeof(Double)));

            // Store the table in session state to persist its values
            // between posts to the server.
            Session["ShoppingCart"] = Cart;
             
            // Populate the DataTable with sample data.
            for (int i = 1; i <= 9; i++) 
            {
               dr = Cart.NewRow();
               if (i % 2 != 0)
               {
                  dr[0] = 2;
               }
               else
               {
                  dr[0] = 1;
               }
               dr[1] = "Item " + i.ToString();
               dr[2] = (1.23 * (i + 1));
               Cart.Rows.Add(dr);
            }

         } 

         else
         {

            // Retrieve the sample data from session state.
            Cart = (DataTable)Session["ShoppingCart"];

         }         
 
         // Create a DataView and specify the field to sort by.
         CartView = new DataView(Cart);
         CartView.Sort="Item";

         return;

      }

      void Edit_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Set the EditItemIndex property to the index of the item clicked
         // in the DataList control to enable editing for that item. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = e.Item.ItemIndex;
         BindList();

      }

      void Cancel_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Set the EditItemIndex property to -1 to exit editing mode. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

      void Delete_Command(Object sender, DataListCommandEventArgs e) 
      { 

         // Retrieve the name of the item to remove.
         String item = ((Label)e.Item.FindControl("ItemLabel")).Text;

         // Filter the CartView for the selected item and remove it from
         // the data source.
         CartView.RowFilter = "Item='" + item + "'";
         if (CartView.Count > 0) 
         {
            CartView.Delete(0);
         }
         CartView.RowFilter = "";

         // Set the EditItemIndex property to -1 to exit editing mode. Be sure
         // to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

      void Update_Command(Object sender, DataListCommandEventArgs e) 
      {

         // Retrieve the updated values from the selected item.
         String item = ((Label)e.Item.FindControl("ItemLabel")).Text;
         String qty = ((TextBox)e.Item.FindControl("QtyTextBox")).Text;
         String price = ((TextBox)e.Item.FindControl("PriceTextBox")).Text;

         // With a database, use an update command to update the data.
         // Because the data source in this example is an in-memory 
         // DataTable, delete the old row and replace it with a new one.

         // Filter the CartView for the selected item and remove it from
         // the data source.
         CartView.RowFilter = "Item='" + item + "'";
         if (CartView.Count > 0)
         {
            CartView.Delete(0);
         }
         CartView.RowFilter = "";

         // ***************************************************************
         // Insert data validation code here. Make sure to validate the
         // values entered by the user before converting to the appropriate
         // data types and updating the data source.
         // ***************************************************************

         // Add a new entry to replace the previous item.
         DataRow dr = Cart.NewRow();
         dr[0] = qty;
         dr[1] = item;
         // If necessary, remove the '$' character from the price before
         // converting the price to a Double.
         if(price[0] == '$')
         {
            dr[2] = Convert.ToDouble(price.Substring(1));
         }
         else
         {
            dr[2] = Convert.ToDouble(price);
         }
         Cart.Rows.Add(dr);

         // Set the EditItemIndex property to -1 to exit editing mode. 
         // Be sure to rebind the DataList to the data source to refresh
         // the control.
         ItemsList.EditItemIndex = -1;
         BindList();

      }

   </script>

</head>
<body>

   <form id="form1" runat="server">

      <h3>DataList Edit Example</h3>

      Click <b>Edit</b> to edit the values of the item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           RepeatColumns="3"
           RepeatDirection="Horizontal"
           CellPadding="3"
           CellSpacing="0"
           runat="server">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <EditItemStyle BackColor="yellow">
         </EditItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            Item:
            <%# DataBinder.Eval(Container.DataItem, "Item") %> 

            <br />

            Quantity:
            <%# DataBinder.Eval(Container.DataItem, "Qty") %>

            <br />

            Price:
            <%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>

            <br />

            <asp:LinkButton id="EditButton" 
                 Text="Edit" 
                 CommandName="Edit"
                 runat="server"/>

         </ItemTemplate>
              
         <EditItemTemplate>

            Item:
            <asp:Label id="ItemLabel" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>' 
                 runat="server"/>

            <br />

            Quantity:
            <asp:TextBox id="QtyTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>' 
                 runat="server"/>

            <br />

            Price:
            <asp:TextBox id="PriceTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>' 
                 runat="server"/>

            <br />

            <asp:LinkButton id="UpdateButton" 
                 Text="Update" 
                 CommandName="Update" 
                 runat="server"/>

            <asp:LinkButton id="DeleteButton" 
                 Text="Delete" 
                 CommandName="Delete" 
                 runat="server"/>

            <asp:LinkButton id="CancelButton" 
                 Text="Cancel" 
                 CommandName="Cancel" 
                 runat="server"/>

         </EditItemTemplate>

      </asp:DataList>

   </form>

</body>
</html>


<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!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>
    <title>DataList Edit Example</title>
<script runat="server">

      ' The Cart and CartView objects temporarily store the data source
      ' for the DataList control while the page is being processed.
      Dim Cart As DataTable = New DataTable()
      Dim CartView As DataView
 
      Sub Page_Load(sende As Object, e As EventArgs) 
 
         ' With a database, use an select query to retrieve the data.
         ' Because the data source in this example is an in-memory
         ' DataTable, retrieve the data from session state if it exists;
         ' otherwise, create the data source.
         GetSource()

         ' The DataGrid control maintains state between posts to the server;
         ' it only needs to be bound to a data source the first time the
         ' page is loaded or when the data source is updated.
         If Not IsPostBack Then

            BindList()

         End If

         ' Manually register the event-handling methods.
         AddHandler ItemsList.EditCommand, AddressOf Edit_Command
         AddHandler ItemsList.UpdateCommand, AddressOf Update_Command
         AddHandler ItemsList.DeleteCommand, AddressOf Delete_Command
         AddHandler ItemsList.CancelCommand, AddressOf Cancel_Command
                   
      End Sub

      Sub BindList() 

         ' Set the data source and bind to the DataList control.
         ItemsList.DataSource = CartView
         ItemsList.DataBind()

      End Sub

      Sub GetSource()

         ' For this example, the data source is a DataTable that
         ' is stored in session state. If the data source does not exist,
         ' create it; otherwise, load the data.
         If Session("ShoppingCart") Is Nothing Then 

            ' Create the sample data.
            Dim dr As DataRow  
 
            ' Define the columns of the table.
            Cart.Columns.Add(new DataColumn("Qty", GetType(Int32)))
            Cart.Columns.Add(new DataColumn("Item", GetType(String)))
            Cart.Columns.Add(new DataColumn("Price", GetType(Double)))

            ' Store the table in session state to persist its values
            ' between posts to the server.
            Session("ShoppingCart") = Cart
             
            ' Populate the DataTable with sample data.
            Dim i As Integer

            For i = 1 To 9 
            
               dr = Cart.NewRow()
               If (i Mod 2) <> 0 Then

                  dr(0) = 2
               
               Else
               
                  dr(0) = 1
               
               End If

               dr(1) = "Item " & i.ToString()
               dr(2) = (1.23 * (i + 1))
               Cart.Rows.Add(dr)
            
            Next i

         Else

            ' Retrieve the sample data from session state.
            Cart = CType(Session("ShoppingCart"), DataTable)

         End If         
 
         ' Create a DataView and specify the field to sort by.
         CartView = New DataView(Cart)
         CartView.Sort="Item"

         Return

      End Sub

      Sub Edit_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Set the EditItemIndex property to the index of the item clicked
         ' in the DataList control to enable editing for that item. Be sure
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = e.Item.ItemIndex
         BindList()

      End Sub

      Sub Cancel_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Set the EditItemIndex property to -1 to exit editing mode. Be sure
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

      Sub Delete_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Retrieve the name of the item to remove.
         Dim item As String = (CType(e.Item.FindControl("ItemLabel"), Label)).Text

         ' Filter the CartView for the selected item and remove it from 
         ' the data source.
         CartView.RowFilter = "Item='" & item & "'"
         If CartView.Count > 0 Then 
       
            CartView.Delete(0)
         
         End If
         CartView.RowFilter = ""

         ' Set the EditItemIndex property to -1 to exit editing mode. Be sure 
         ' to rebind the DataList to the data source to refresh the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

      Sub Update_Command(sender As Object, e As DataListCommandEventArgs) 

         ' Retrieve the updated values from the selected item.
         Dim item As String = _
             (CType(e.Item.FindControl("ItemLabel"), Label)).Text
         Dim qty As String = _
             (CType(e.Item.FindControl("QtyTextBox"), TextBox)).Text
         Dim price As String = _
             (CType(e.Item.FindControl("PriceTextBox"), TextBox)).Text

         ' With a database, use an update command to update the data.
         ' Because the data source in this example is an in-memory 
         ' DataTable, delete the old row and replace it with a new one.

         ' Filter the CartView for the selected item and remove it from 
         ' the data source.
         CartView.RowFilter = "Item='" & item & "'"
         If CartView.Count > 0 Then 
       
            CartView.Delete(0)
         
         End If
         CartView.RowFilter = ""

         ' ***************************************************************
         ' Insert data validation code here. Make sure to validate the
         ' values entered by the user before converting to the appropriate
         ' data types and updating the data source.
         ' ***************************************************************

         ' Add a new entry to replace the previous item.
         Dim dr As DataRow = Cart.NewRow()
         dr(0) = qty
         dr(1) = item
         ' If necessary, remove the '$' character from the price before 
         ' converting the price to a Double.
         If price.Chars(0) = "$" Then

            dr(2) = Convert.ToDouble(price.Substring(1))

         Else

            dr(2) = Convert.ToDouble(price)
         
         End If

         Cart.Rows.Add(dr)

         ' Set the EditItemIndex property to -1 to exit editing mode. 
         ' Be sure to rebind the DataList to the data source to refresh 
         ' the control.
         ItemsList.EditItemIndex = -1
         BindList()

      End Sub

   </script>

</head>
<body>

   <form id="form1" runat="server">

      <h3>DataList Edit Example</h3>

      Click <b>Edit</b> to edit the values of the item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           RepeatColumns="3"
           RepeatDirection="Horizontal"
           CellPadding="3"
           CellSpacing="0"
           OnEditCommand="Edit_Command"
           OnUpdateCommand="Update_Command"
           OnDeleteCommand="Delete_Command"
           OnCancelCommand="Cancel_Command"
           runat="server">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <EditItemStyle BackColor="yellow">
         </EditItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            Item:
            <%# DataBinder.Eval(Container.DataItem, "Item") %> 

            <br />

            Quantity:
            <%# DataBinder.Eval(Container.DataItem, "Qty") %>

            <br />

            Price:
            <%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>

            <br />

            <asp:LinkButton id="EditButton" 
                 Text="Edit" 
                 CommandName="Edit"
                 runat="server"/>

         </ItemTemplate>
              
         <EditItemTemplate>

            Item:
            <asp:Label id="ItemLabel" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>' 
                 runat="server"/>

            <br />

            Quantity:
            <asp:TextBox id="QtyTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>' 
                 runat="server"/>

            <br />

            Price:
            <asp:TextBox id="PriceTextBox" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>' 
                 runat="server"/>

            <br />

            <asp:LinkButton id="UpdateButton" 
                 Text="Update" 
                 CommandName="Update" 
                 runat="server"/>

            <asp:LinkButton id="DeleteButton" 
                 Text="Delete" 
                 CommandName="Delete" 
                 runat="server"/>

            <asp:LinkButton id="CancelButton" 
                 Text="Cancel" 
                 CommandName="Cancel" 
                 runat="server"/>

         </EditItemTemplate>

      </asp:DataList>

   </form>

</body>
</html>

Remarques

L' CancelCommand événement est déclenché lorsque l' Cancel utilisateur clique sur le bouton DataList d’un élément dans le contrôle.The CancelCommand event is raised when the Cancel button for an item in the DataList control is clicked.

L' DeleteCommand événement est déclenché lorsque l' Delete utilisateur clique sur le bouton DataList d’un élément dans le contrôle.The DeleteCommand event is raised when the Delete button for an item in the DataList control is clicked.

L' EditCommand événement est déclenché lorsque l' Edit utilisateur clique sur le bouton DataList d’un élément dans le contrôle.The EditCommand event is raised when the Edit button for an item in the DataList control is clicked.

L' ItemCommand événement est déclenché lorsqu’un clic est effectué sur un bouton DataList d’un élément du contrôle.The ItemCommand event is raised when any button for an item in the DataList control is clicked. Cela vous permet de tester par programmation si un clic est effectué sur un bouton de commande spécifique et de prendre les mesures appropriées.This allows you to programmatically test for when a specific command button is clicked and take appropriate action. Cet événement est couramment utilisé pour gérer des boutons de commande personnalisés DataList pour le contrôle.This event is commonly used to handle custom command buttons for the DataList control.

L' UpdateCommand événement est déclenché lorsque l' Update utilisateur clique sur le bouton DataList d’un élément dans le contrôle.The UpdateCommand event is raised when the Update button for an item in the DataList control is clicked.

Lorsque vous créez un délégué DataListCommandEventHandler, vous identifiez la méthode qui gérera l'événement.When you create a DataListCommandEventHandler delegate, you identify the method that will handle the event. Pour associer l'événement au gestionnaire d'événements, ajoutez une instance du délégué à l'événement.To associate the event with your event handler, add an instance of the delegate to the event. Le gestionnaire d'événements est appelé chaque fois qu'un événement se produit, sauf si vous supprimez le délégué.The event handler is called whenever the event occurs, unless you remove the delegate. Pour plus d’informations sur les délégués de gestionnaires d’événements, consultez gestion et déclenchement d’événements.For more information about event handler delegates, see Handling and Raising Events.

Méthodes d’extension

GetMethodInfo(Delegate)

Obtient un objet qui représente la méthode représentée par le délégué spécifié.Gets an object that represents the method represented by the specified delegate.

S’applique à

Voir aussi