Condividi tramite


DataGrid.OnItemDataBound(DataGridItemEventArgs) Metodo

Definizione

Genera l'evento ItemDataBound. In tal modo è possibile fornire un gestore personalizzato per l'evento.

protected:
 virtual void OnItemDataBound(System::Web::UI::WebControls::DataGridItemEventArgs ^ e);
protected virtual void OnItemDataBound (System.Web.UI.WebControls.DataGridItemEventArgs e);
abstract member OnItemDataBound : System.Web.UI.WebControls.DataGridItemEventArgs -> unit
override this.OnItemDataBound : System.Web.UI.WebControls.DataGridItemEventArgs -> unit
Protected Overridable Sub OnItemDataBound (e As DataGridItemEventArgs)

Parametri

e
DataGridItemEventArgs

DataGridItemEventArgs in cui sono contenuti i dati dell'evento.

Esempio

Nell'esempio di codice seguente viene illustrato come specificare e codificare un gestore per l'evento per visualizzare l'ordine ItemDataBound di associazione degli elementi inclusi nei DataGrid dati.

<%@ 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" >
<script language="C#" runat="server">
 
   DataTable Cart;
   DataView CartView;
 
   ICollection CreateDataSource() 
   {
      DataTable dt = new DataTable();
      DataRow dr;
 
      dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
      dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
      dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
 
      for (int i = 0; i < 10; i++) 
      {
         dr = dt.NewRow();
 
         dr[0] = i;
         dr[1] = "Item " + i.ToString();
         dr[2] = 1.23 * (i+1);
 
         dt.Rows.Add(dr);
      }
 
      DataView dv = new DataView(dt);
      return dv;
   }
 
   void Page_Load(Object sender, EventArgs e) 
   {
 
      if (!IsPostBack) 
      {
         // Need to load this data only once.
         ItemsGrid.DataSource = CreateDataSource();
         ItemsGrid.DataBind();
      }
 
   }
 
   void Item_Bound(Object sender, DataGridItemEventArgs e) 
   {
 
      Label1.Text = Label1.Text + " " + e.Item.ItemIndex;
 
   }
 
</script>
 
<head runat="server">
    <title>DataGrid ItemDataBound Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid ItemDataBound Example</h3>
 
      <asp:DataGrid id="ItemsGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="true"
           OnItemDataBound="Item_Bound"
           AutoGenerateColumns="true">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>
   
      </asp:DataGrid>
 
      <br />
 
      <asp:Label id="Label1" 
           Text="Order of items data bound: " 
           runat="server"/>

      <br />

      <asp:Label id="Label2" 
           Text="Note: The -1's refer to the header and footer." 
           runat="server"/>
 
   </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" >
<script language="VB" runat="server">
 
    Dim Cart As DataTable
    Dim CartView As DataView
    Function CreateDataSource() As ICollection
        Dim dt As New DataTable()
        Dim dr As DataRow
        
        dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
        dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
        dt.Columns.Add(New DataColumn("CurrencyValue", GetType(Double)))
        
        Dim i As Integer
        For i = 0 To 9
            dr = dt.NewRow()
            
            dr(0) = i
            dr(1) = "Item " & i.ToString()
            dr(2) = 1.23 *(i + 1)
            
            dt.Rows.Add(dr)
        Next i
        
        Dim dv As New DataView(dt)
        Return dv
    End Function 'CreateDataSource


    Sub Page_Load(sender As Object, e As EventArgs)
        
        If Not IsPostBack Then
            ' Need to load this data only once.
            ItemsGrid.DataSource = CreateDataSource()
            ItemsGrid.DataBind()
        End If
    End Sub 'Page_Load
     

    Sub Item_Bound(sender As Object, e As DataGridItemEventArgs)
        
        Label1.Text = Label1.Text & " " & e.Item.ItemIndex
    End Sub 'Item_Bound 
 
</script>
 
<head runat="server">
    <title>DataGrid ItemDataBound Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid ItemDataBound Example</h3>
 
      <asp:DataGrid id="ItemsGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="true"
           OnItemDataBound="Item_Bound"
           AutoGenerateColumns="true">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>
   
      </asp:DataGrid>
 
      <br />
 
      <asp:Label id="Label1" 
           Text="Order of items data bound: " 
           runat="server"/>

      <br />

      <asp:Label id="Label2" 
           Text="Note: The -1's refer to the header and footer." 
           runat="server"/>
 
   </form>
 
</body>
</html>

<%@ Page Language="C#" AutoEventWireup="True" Debug="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" >
   <script runat="server">
 
      ICollection CreateDataSource()
      {

         // Create sample data for the DataGrid control.
         DataTable dt = new DataTable();
         DataRow dr;
 
         // Define the columns of the table.
         dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
         dt.Columns.Add(new DataColumn("StringValue", typeof(String)));
         dt.Columns.Add(new DataColumn("CurrencyValue", typeof(Double)));
 
         // Populate the table with sample values.
         for (int i=0; i<=10; i++) 
         {

            dr = dt.NewRow();
 
            dr[0] = i;
            dr[1] = "Item " + i.ToString();
            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)
         { 
         
            ItemsGrid.DataSource = CreateDataSource();
            ItemsGrid.DataBind();
         
         }

      }
 
      void Item_Bound(Object sender, DataGridItemEventArgs e) 
      {
 
         // Use the ItemDataBound event to customize the DataGrid control. 
         // The ItemDataBound event allows you to access the data before 
         // the item is displayed in the control. In this example, the 
         // ItemDataBound event is used to format the items in the 
         // CurrencyColumn in currency format.
         if((e.Item.ItemType == ListItemType.Item) || 
             (e.Item.ItemType == ListItemType.AlternatingItem))
         {
 
            // Retrieve the text of the CurrencyColumn from the DataGridItem
            // and convert the value to a Double.
            Double Price = Convert.ToDouble(e.Item.Cells[2].Text);

            // Format the value as currency and redisplay it in the DataGrid.
            e.Item.Cells[2].Text = Price.ToString("c");
        
         }         
 
      }
 
</script>
 
<head runat="server">
    <title>DataGrid ItemDataBound Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid ItemDataBound Example</h3>
 
      <asp:DataGrid id="ItemsGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="true"
           OnItemDataBound="Item_Bound">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>
   
      </asp:DataGrid>

   </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" >
   <script runat="server">
 
      Function CreateDataSource() As ICollection

         ' Create sample data for the DataGrid control.
         Dim dt As DataTable = New DataTable()
         Dim dr As DataRow 
 
         ' Define the columns of the table.
         dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
         dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
         dt.Columns.Add(New DataColumn("CurrencyValue", GetType(Double)))
 
         ' Populate the table with sample values.
         Dim i As Integer         

         For i=0 To 10 

            dr = dt.NewRow()
 
            dr(0) = i
            dr(1) = "Item " & i.ToString()
            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
         
            ItemsGrid.DataSource = CreateDataSource()
            ItemsGrid.DataBind()
         
         End If

      End Sub
 
      Sub Item_Bound(sender As Object, e As DataGridItemEventArgs) 
 
         ' Use the ItemDataBound event to customize the DataGrid control. 
         ' The ItemDataBound event allows you to access the data before 
         ' the item is displayed in the control. In this example, the 
         ' ItemDataBound event is used to format the items in the 
         ' CurrencyColumn in currency format.
         If e.Item.ItemType = ListItemType.Item Or _
             e.Item.ItemType = ListItemType.AlternatingItem Then
 
            ' Retrieve the text of the CurrencyColumn from the DataGridItem
            ' and convert the value to a Double.
            Dim Price As Double = Convert.ToDouble(e.Item.Cells(2).Text)

            ' Format the value as currency and redisplay it in the DataGrid.
            e.Item.Cells(2).Text = Price.ToString("c")
        
         End If         
 
      End Sub
 
</script>
 
<head runat="server">
    <title>DataGrid ItemDataBound Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid ItemDataBound Example</h3>
 
      <asp:DataGrid id="ItemsGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="true"
           OnItemDataBound="Item_Bound">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>
   
      </asp:DataGrid>

   </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" >
   <script runat="server">
 
      ICollection CreateDataSource()
      {

         // Create sample data for the DataGrid control.
         DataTable dt = new DataTable();
         DataRow dr;
 
         // Define the columns of the table.
         dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
         dt.Columns.Add(new DataColumn("StringValue", typeof(String)));
         dt.Columns.Add(new DataColumn("CurrencyValue", typeof(Double)));
 
         // Populate the table with sample values.
         for (int i=0; i<=10; i++) 
         {

            dr = dt.NewRow();
 
            dr[0] = i;
            dr[1] = "Item " + i.ToString();
            dr[2] = 1.23 * (i + 1);
 
            dt.Rows.Add(dr);
         
         }
 
         DataView dv = new DataView(dt);

         return dv;
      
      }
 
      void Page_Load(Object sender, EventArgs e)
      { 
 
         // Manually register the event-handling method for the  
         // ItemDataBound event of the DataGrid control.
         ItemsGrid.ItemDataBound += 
             new DataGridItemEventHandler(this.Item_Bound);

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

      }
 
      void Item_Bound(Object sender, DataGridItemEventArgs e) 
      {
 
         // Use the ItemDataBound event to customize the DataGrid control. 
         // The ItemDataBound event allows you to access the data before 
         // the item is displayed in the control. In this example, the 
         // ItemDataBound event is used to format the items in the 
         // CurrencyColumn in currency format.
         if((e.Item.ItemType == ListItemType.Item) ||
             (e.Item.ItemType == ListItemType.AlternatingItem))
         {
 
            // Retrieve the text of the CurrencyColumn from the DataGridItem
            // and convert the value to a Double.
            Double Price = Convert.ToDouble(e.Item.Cells[2].Text);

            // Format the value as currency and redisplay it in the DataGrid.
            e.Item.Cells[2].Text = Price.ToString("c");
        
         }         
 
      }
 
</script>
 
<head runat="server">
    <title>DataGrid ItemDataBound Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid ItemDataBound Example</h3>
 
      <asp:DataGrid id="ItemsGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="true">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>
   
      </asp:DataGrid>

   </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" >
   <script runat="server">
 
      Function CreateDataSource() As ICollection

         ' Create sample data for the DataGrid control.
         Dim dt As DataTable = New DataTable()
         Dim dr As DataRow 
 
         ' Define the columns of the table.
         dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
         dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
         dt.Columns.Add(New DataColumn("CurrencyValue", GetType(Double)))
 
         ' Populate the table with sample values.
         Dim i As Integer         

         For i=0 To 10 

            dr = dt.NewRow()
 
            dr(0) = i
            dr(1) = "Item " & i.ToString()
            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)

         ' Manually register the event-handling method for the  
         ' ItemDataBound event of the DataGrid control.
         AddHandler ItemsGrid.ItemDataBound, AddressOf Item_Bound
 
         ' Load sample data only once, when the page is first loaded.
         If Not IsPostBack Then
         
            ItemsGrid.DataSource = CreateDataSource()
            ItemsGrid.DataBind()
         
         End If

      End Sub
 
      Sub Item_Bound(sender As Object, e As DataGridItemEventArgs) 
 
         ' Use the ItemDataBound event to customize the DataGrid control. 
         ' The ItemDataBound event allows you to access the data before 
         ' the item is displayed in the control. In this example, the 
         ' ItemDataBound event is used to format the items in the 
         ' CurrencyColumn in currency format.
         If e.Item.ItemType = ListItemType.Item Or _
             e.Item.ItemType = ListItemType.AlternatingItem Then
 
            ' Retrieve the text of the CurrencyColumn from the DataGridItem
            ' and convert the value to a Double.
            Dim Price As Double = Convert.ToDouble(e.Item.Cells(2).Text)

            ' Format the value as currency and redisplay it in the DataGrid.
            e.Item.Cells(2).Text = Price.ToString("c")
        
         End If         
 
      End Sub
 
</script>
 
<head runat="server">
    <title>DataGrid ItemDataBound Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid ItemDataBound Example</h3>
 
      <asp:DataGrid id="ItemsGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="true">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>
   
      </asp:DataGrid>

   </form>
 
</body>
</html>

Commenti

Usare il OnItemDataBound metodo per fornire un gestore personalizzato per l'evento ItemDataBound .

L'evento ItemDataBoundDataGrid viene generato dopo che un elemento è associato al controllo. Questo evento offre l'ultima opportunità di accedere all'elemento di dati prima che venga visualizzato nel client. Dopo aver generato questo evento, l'elemento di dati viene disattivato e non è più disponibile.

Quando viene generato un evento, il gestore dell'evento viene richiamato tramite un delegato. Per altre informazioni, vedere la gestione e generazione di eventi.

Note per gli eredi

Quando si esegue l'override OnItemDataBound(DataGridItemEventArgs) in una classe derivata, assicurarsi di chiamare il metodo della OnItemDataBound(DataGridItemEventArgs) classe base.

Per altre informazioni su come gestire gli eventi, vedere la gestione e generazione di eventi.

Si applica a

Vedi anche