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DataList.ItemCommand Evento

Definizione

Si verifica quando si fa clic su un pulsante qualsiasi nel controllo DataList.

public:
 event System::Web::UI::WebControls::DataListCommandEventHandler ^ ItemCommand;
public event System.Web.UI.WebControls.DataListCommandEventHandler ItemCommand;
member this.ItemCommand : System.Web.UI.WebControls.DataListCommandEventHandler 
Public Custom Event ItemCommand As DataListCommandEventHandler 

Tipo evento

Esempio

Nell'esempio di codice seguente viene illustrato come specificare e codice un gestore per l'evento ItemCommand per selezionare un elemento dal DataList controllo.

Nota

L'esempio di codice seguente usa il modello di codice a file singolo e potrebbe non funzionare correttamente se copiato direttamente in un file code-behind. Questo esempio di codice deve essere copiato in un file di testo vuoto con un'estensione .aspx. Per altre informazioni sul modello di codice Web Forms, vedere ASP.NET modello di codice della pagina Web Forms.


<%@ 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 Select Example</title>
<script runat="server">

      ICollection CreateDataSource() 
      {
      
         // Create sample data for the DataList control.
         DataTable dt = new DataTable();
         DataRow dr;
 
         // Define the columns of the table.
         dt.Columns.Add(new DataColumn("Item", typeof(Int32)));
         dt.Columns.Add(new DataColumn("Qty", typeof(Int32)));
         dt.Columns.Add(new DataColumn("Price", typeof(double)));
 
         // Populate the table with sample values.
         for (int i = 0; i < 9; i++) 
         {
            dr = dt.NewRow();
 
            dr[0] = i;
            dr[1] = i * 2;
            dr[2] = 1.23 * (i + 1);
 
            dt.Rows.Add(dr);
         }
 
         DataView dv = new DataView(dt);
         return dv;

      }
 
      void Page_Load(Object sender, EventArgs e) 
      {

         // Load sample data only once, when the page is first loaded.
         if (!IsPostBack) 
         {
            ItemsList.DataSource = CreateDataSource();
            ItemsList.DataBind();
         }

      }

      void Item_Command(Object sender, DataListCommandEventArgs e) 
      {
        
         // Set the SelectedIndex property to select an item in the DataList.
         ItemsList.SelectedIndex = e.Item.ItemIndex;

         // Rebind the data source to the DataList to refresh the control.
         ItemsList.DataSource = CreateDataSource();
         ItemsList.DataBind();

      }

   </script>

</head>
<body>

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

      <h3>DataList Select Example</h3>

      Click <b>Select</b> to select an item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           CellPadding="3"
           CellSpacing="0"           
           OnItemCommand="Item_Command"
           runat="server">

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

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

         <SelectedItemStyle BackColor="Yellow">
         </SelectedItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            <asp:LinkButton id="SelectButton" 
                 Text="Select" 
                 CommandName="Select"
                 runat="server"/>

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

         </ItemTemplate>
              
         <SelectedItemTemplate>

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

            <br />

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

            <br />

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

         </SelectedItemTemplate>

      </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 Select Example</title>
<script runat="server">

      Function CreateDataSource() As ICollection 
      
         ' Create sample data for the DataList control.
         Dim dt As DataTable = New DataTable()
         Dim dr As DataRow
 
         ' Define the columns of the table.
         dt.Columns.Add(New DataColumn("Item", GetType(Int32)))
         dt.Columns.Add(New DataColumn("Qty", GetType(Int32)))
         dt.Columns.Add(New DataColumn("Price", GetType(Double)))
 
         ' Populate the table with sample values.
         Dim i As Integer

         For i = 0 To 8 

            dr = dt.NewRow()
 
            dr(0) = i
            dr(1) = i * 2
            dr(2) = 1.23 * (i + 1)
 
            dt.Rows.Add(dr)
         
         Next i
 
         Dim dv As DataView = New DataView(dt)
         Return dv
      
      End Function
 
      Sub Page_Load(sender As Object, e As EventArgs) 

         ' Load sample data only once, when the page is first loaded.
         If Not IsPostBack Then 
         
            ItemsList.DataSource = CreateDataSource()
            ItemsList.DataBind()
         
         End If

      End Sub

      Sub Item_Command(sender As Object, e As DataListCommandEventArgs) 
        
         ' Set the SelectedIndex property to select an item in the DataList.
         ItemsList.SelectedIndex = e.Item.ItemIndex

         ' Rebind the data source to the DataList to refresh the control.
         ItemsList.DataSource = CreateDataSource()
         ItemsList.DataBind()

      End Sub

   </script>

</head>
<body>

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

      <h3>DataList Select Example</h3>

      Click <b>Select</b> to select an item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           CellPadding="3"
           CellSpacing="0"           
           OnItemCommand="Item_Command"
           runat="server">

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

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

         <SelectedItemStyle BackColor="Yellow">
         </SelectedItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            <asp:LinkButton id="SelectButton" 
                 Text="Select" 
                 CommandName="Select"
                 runat="server"/>

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

         </ItemTemplate>
              
         <SelectedItemTemplate>

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

            <br />

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

            <br />

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

         </SelectedItemTemplate>

      </asp:DataList>

   </form>

</body>
</html>

<%@ 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 Select Example</title>
<script runat="server">

      ICollection CreateDataSource() 
      {
      
         // Create sample data for the DataList control.
         DataTable dt = new DataTable();
         DataRow dr;
 
         // Define the columns of the table.
         dt.Columns.Add(new DataColumn("Item", typeof(Int32)));
         dt.Columns.Add(new DataColumn("Qty", typeof(Int32)));
         dt.Columns.Add(new DataColumn("Price", typeof(double)));
 
         // Populate the table with sample values.
         for (int i = 0; i < 9; i++) 
         {
            dr = dt.NewRow();
 
            dr[0] = i;
            dr[1] = i * 2;
            dr[2] = 1.23 * (i + 1);
 
            dt.Rows.Add(dr);
         }
 
         DataView dv = new DataView(dt);
         return dv;

      }
 
      void Page_Load(Object sender, EventArgs e) 
      {

         // Load sample data only once, when the page is first loaded.
         if (!IsPostBack) 
         {
            ItemsList.DataSource = CreateDataSource();
            ItemsList.DataBind();
         }

         // Manually register the event-handling method for the 
         // ItemCommand event.
         ItemsList.ItemCommand += 
             new DataListCommandEventHandler(this.Item_Command);

      }

      void Item_Command(Object sender, DataListCommandEventArgs e) 
      {
        
         // Set the SelectedIndex property to select an item in the DataList.
         ItemsList.SelectedIndex = e.Item.ItemIndex;

         // Rebind the data source to the DataList to refresh the control.
         ItemsList.DataSource = CreateDataSource();
         ItemsList.DataBind();

      }

   </script>

</head>
<body>

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

      <h3>DataList Select Example</h3>

      Click <b>Select</b> to select an item.

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

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

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

         <SelectedItemStyle BackColor="Yellow">
         </SelectedItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            <asp:LinkButton id="SelectButton" 
                 Text="Select" 
                 CommandName="Select"
                 runat="server"/>

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

         </ItemTemplate>
              
         <SelectedItemTemplate>

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

            <br />

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

            <br />

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

         </SelectedItemTemplate>

      </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 Select Example</title>
<script runat="server">

      Function CreateDataSource() As ICollection 
      
         ' Create sample data for the DataList control.
         Dim dt As DataTable = New DataTable()
         Dim dr As DataRow
 
         ' Define the columns of the table.
         dt.Columns.Add(New DataColumn("Item", GetType(Int32)))
         dt.Columns.Add(New DataColumn("Qty", GetType(Int32)))
         dt.Columns.Add(New DataColumn("Price", GetType(Double)))
 
         ' Populate the table with sample values.
         Dim i As Integer

         For i = 0 To 8 

            dr = dt.NewRow()
 
            dr(0) = i
            dr(1) = i * 2
            dr(2) = 1.23 * (i + 1)
 
            dt.Rows.Add(dr)
         
         Next i
 
         Dim dv As DataView = New DataView(dt)
         Return dv
      
      End Function
 
      Sub Page_Load(sender As Object, e As EventArgs) 

         ' Load sample data only once, when the page is first loaded.
         If Not IsPostBack Then 
         
            ItemsList.DataSource = CreateDataSource()
            ItemsList.DataBind()
         
         End If

         ' Manually register the event-handling method for the 
         ' ItemCommand event.
         AddHandler ItemsList.ItemCommand, AddressOf Item_Command

      End Sub

      Sub Item_Command(sender As Object, e As DataListCommandEventArgs) 
        
         ' Set the SelectedIndex property to select an item in the DataList.
         ItemsList.SelectedIndex = e.Item.ItemIndex

         ' Rebind the data source to the DataList to refresh the control.
         ItemsList.DataSource = CreateDataSource()
         ItemsList.DataBind()

      End Sub

   </script>

</head>
<body>

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

      <h3>DataList Select Example</h3>

      Click <b>Select</b> to select an item.

      <br /><br />
       
      <asp:DataList id="ItemsList"
           GridLines="Both"
           CellPadding="3"
           CellSpacing="0"           
           OnItemCommand="Item_Command"
           runat="server">

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

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

         <SelectedItemStyle BackColor="Yellow">
         </SelectedItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            <asp:LinkButton id="SelectButton" 
                 Text="Select" 
                 CommandName="Select"
                 runat="server"/>

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

         </ItemTemplate>
              
         <SelectedItemTemplate>

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

            <br />

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

            <br />

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

         </SelectedItemTemplate>

      </asp:DataList>

   </form>

</body>
</html>

Commenti

L'evento ItemCommand viene generato quando un pulsante viene fatto clic nel DataList controllo e viene comunemente usato quando si dispone di un controllo pulsante con un valore personalizzato CommandName .

Per altre informazioni sulla gestione degli eventi, vedere Procedura: Usare eventi in un'applicazione Web Form.

Si applica a

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