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DataGridColumnCollection.Remove(DataGridColumn) Méthode

Définition

Supprime de la collection DataGridColumn l'objet de colonne dérivé de DataGridColumnCollection spécifié.

public:
 void Remove(System::Web::UI::WebControls::DataGridColumn ^ column);
public void Remove (System.Web.UI.WebControls.DataGridColumn column);
member this.Remove : System.Web.UI.WebControls.DataGridColumn -> unit
Public Sub Remove (column As DataGridColumn)

Paramètres

column
DataGridColumn

Colonne dérivée de DataGridColumn à supprimer de DataGridColumnCollection.

Exemples

L’exemple de code suivant montre comment utiliser la Remove méthode pour supprimer une colonne de la DataGridColumnCollection collection. Notez que la Columns propriété du DataGrid contrôle est la DataGridColumnCollection collection.

<%@ 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 < 9; 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 (Session["DG4_ShoppingCart"] == null) 
         {
            Cart = new DataTable();
            Cart.Columns.Add(new DataColumn("Item", typeof(string)));
            Cart.Columns.Add(new DataColumn("Price", typeof(string)));
            Session["DG4_ShoppingCart"] = Cart;
         }
         else 
         {
            Cart = (DataTable)Session["DG4_ShoppingCart"];
         }    
         CartView = new DataView(Cart);
         ShoppingCart.DataSource = CartView;
         ShoppingCart.DataBind();
 
         if (!IsPostBack) 
         {
            // Load this data only once.
            ItemsGrid.DataSource= CreateDataSource();
            ItemsGrid.DataBind();
         }

      }
  
      void Grid_CartCommand(Object sender, DataGridCommandEventArgs e) {
     
         DataRow dr = Cart.NewRow();
          
         // e.Item is the table row where the command is raised.
         // For bound columns, the value is stored in the Text property of the TableCell.
         TableCell itemCell = e.Item.Cells[2];
         TableCell priceCell = e.Item.Cells[3];
         string item = itemCell.Text;
         string price = priceCell.Text;
         
         if (((Button)e.CommandSource).CommandName == "AddToCart") 
         {
            dr[0] = item;
            dr[1] = price;
            Cart.Rows.Add(dr);
         }
         else 
         { 

            //Remove from Cart.
         
            CartView.RowFilter = "Item='" + item + "'";
            if (CartView.Count > 0) 
            {    
               CartView.Delete(0);
            }
            CartView.RowFilter = "";
         }
         ShoppingCart.DataBind();
 
      }

       void Button_Click(Object sender, EventArgs e) 
      {
         ItemsGrid.Columns.Remove(ItemsGrid.Columns[2]);
      }
 
   </script>
 
<head runat="server">
    <title>DataGridColumnCollection Remove Example</title>
</head>
<body>
 
   <form id="form1" runat="server">
 
      <h3>DataGridColumnCollection Remove Example</h3>
 
      <table cellpadding="5">
         <tr valign="top">
            <td>
 
               <b>Product List</b>
 
               <asp:DataGrid id="ItemsGrid"
                    BorderColor="black"
                    BorderWidth="1"
                    CellPadding="3"
                    AutoGenerateColumns="false"
                    OnItemCommand="Grid_CartCommand"
                    runat="server">

                  <HeaderStyle BackColor="#00aaaa">
                  </HeaderStyle>
 
                  <Columns>
 
                     <asp:ButtonColumn 
                          HeaderText="Add to cart" 
                          ButtonType="PushButton" 
                          Text="Add" 
                          CommandName="AddToCart"/>
 
                     <asp:ButtonColumn 
                          HeaderText="Remove from cart" 
                          ButtonType="PushButton" 
                          Text="Remove" 
                          CommandName="RemoveFromCart"/>
                  
                     <asp:BoundColumn 
                          HeaderText="Item Number" 
                          DataField="IntegerValue"/>
 
                     <asp:BoundColumn 
                          HeaderText="Item" 
                          DataField="StringValue"/>
 
                     <asp:BoundColumn 
                          HeaderText="Price" 
                          DataField="CurrencyValue" 
                          DataFormatString="{0:c}">

                        <ItemStyle HorizontalAlign="right">
                        </ItemStyle>

                     </asp:BoundColumn>
 
                  </Columns>
   
               </asp:DataGrid>
 
            </td>
            <td>
 
               <b>Shopping Cart</b>
 
               <asp:DataGrid id="ShoppingCart" 
                    runat="server"
                    BorderColor="black"
                    BorderWidth="1"
                    GridLines="Both"
                    ShowFooter="false"
                    CellPadding="3"
                    CellSpacing="0">

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

                </asp:DataGrid>
 
            </td>
         </tr>
 
      </table>

      <asp:Button id="Button1" 
           Text="Remove Item Number Column"
           OnClick="Button_Click"
           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 8
                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 Session("DG4_ShoppingCart") Is Nothing Then
                Cart = New DataTable()
                Cart.Columns.Add(New DataColumn("Item", GetType(String)))
                Cart.Columns.Add(New DataColumn("Price", GetType(String)))
                Session("DG4_ShoppingCart") = Cart
            Else
                Cart = CType(Session("DG4_ShoppingCart"), DataTable)
            End If
            CartView = New DataView(Cart)
            ShoppingCart.DataSource = CartView
            ShoppingCart.DataBind()
            
            If Not IsPostBack Then
                ' Load this data only once.
                ItemsGrid.DataSource = CreateDataSource()
                ItemsGrid.DataBind()
            End If
        End Sub 'Page_Load
         

        Sub Grid_CartCommand(sender As Object, e As DataGridCommandEventArgs)
            
            Dim dr As DataRow = Cart.NewRow()
            
            ' e.Item is the table row where the command is raised.
            ' For bound columns, the value is stored in the Text property of the TableCell.
            Dim itemCell As TableCell = e.Item.Cells(2)
            Dim priceCell As TableCell = e.Item.Cells(3)
            Dim item As String = itemCell.Text
            Dim price As String = priceCell.Text
            
            If CType(e.CommandSource, Button).CommandName = "AddToCart" Then
                dr(0) = item
                dr(1) = price
                Cart.Rows.Add(dr)
            Else 

                'Remove from Cart.
                CartView.RowFilter = "Item='" & item & "'"
                If CartView.Count > 0 Then
                    CartView.Delete(0)
                End If
                CartView.RowFilter = ""

            End If
            ShoppingCart.DataBind()
        End Sub 'Grid_CartCommand
         

        Sub Button_Click(sender As Object, e As EventArgs)
            ItemsGrid.Columns.Remove(ItemsGrid.Columns(2))
        End Sub 'Button_Click
 
   </script>
 
<head runat="server">
    <title>DataGridColumnCollection Remove Example</title>
</head>
<body>
 
   <form id="form1" runat="server">
 
      <h3>DataGridColumnCollection Remove Example</h3>
 
      <table cellpadding="5">
         <tr valign="top">
            <td>
 
               <b>Product List</b>
 
               <asp:DataGrid id="ItemsGrid"
                    BorderColor="black"
                    BorderWidth="1"
                    CellPadding="3"
                    AutoGenerateColumns="false"
                    OnItemCommand="Grid_CartCommand"
                    runat="server">

                  <HeaderStyle BackColor="#00aaaa">
                  </HeaderStyle>
 
                  <Columns>
 
                     <asp:ButtonColumn 
                          HeaderText="Add to cart" 
                          ButtonType="PushButton" 
                          Text="Add" 
                          CommandName="AddToCart"/>
 
                     <asp:ButtonColumn 
                          HeaderText="Remove from cart" 
                          ButtonType="PushButton" 
                          Text="Remove" 
                          CommandName="RemoveFromCart"/>
                  
                     <asp:BoundColumn 
                          HeaderText="Item Number" 
                          DataField="IntegerValue"/>
 
                     <asp:BoundColumn 
                          HeaderText="Item" 
                          DataField="StringValue"/>
 
                     <asp:BoundColumn 
                          HeaderText="Price" 
                          DataField="CurrencyValue" 
                          DataFormatString="{0:c}">

                        <ItemStyle HorizontalAlign="right">
                        </ItemStyle>

                     </asp:BoundColumn>
 
                  </Columns>
   
               </asp:DataGrid>
 
            </td>
            <td>
 
               <b>Shopping Cart</b>
 
               <asp:DataGrid id="ShoppingCart" 
                    runat="server"
                    BorderColor="black"
                    BorderWidth="1"
                    GridLines="Both"
                    ShowFooter="false"
                    CellPadding="3"
                    CellSpacing="0">

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

                </asp:DataGrid>
 
            </td>
         </tr>
 
      </table>

      <asp:Button id="Button1" 
           Text="Remove Item Number Column"
           OnClick="Button_Click"
           runat="server"/>
 
   </form>
 
</body>
</html>

Remarques

Utilisez cette méthode pour supprimer l’objet de colonne dérivé spécifié DataGridColumnd’une DataGridColumnCollection collection.

Le DataGrid contrôle ne stocke pas le contenu de sa Columns collection dans l’état d’affichage. Pour ajouter ou supprimer une colonne dynamiquement, vous devez ajouter ou supprimer la colonne chaque fois que la page est actualisée. Fournissez une Page_Init fonction qui ajoute ou supprime la colonne avant que le DataGrid contrôle puisse recharger son état et se reconstruire. Sinon, les modifications apportées à la Columns collection ne sont pas reflétées dans le DataGrid contrôle lorsqu’elle est affichée.

Notes

Bien que vous puissiez ajouter par programmation des colonnes à ou supprimer des colonnes de la Columns collection du DataGrid contrôle, il est plus facile de répertorier les colonnes statiquement, puis d’utiliser la Visible propriété pour afficher ou masquer chaque colonne.

S’applique à

Voir aussi