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DataGridColumnCollection.IndexOf Method

Returns the index of the specified DataGridColumn-derived column object from the DataGridColumnCollection collection.

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

public int IndexOf(
	DataGridColumn column
)

Parameters

column
Type: System.Web.UI.WebControls.DataGridColumn

The DataGridColumn-derived column to search for in the DataGridColumnCollection.

Return Value

Type: System.Int32
The index position of the specified DataGridColumn-derived column in the DataGridColumnCollection. The default value is -1, which indicates that the specified DataGridColumn-derived object is not found.

Use this method to determine the index number of the specified DataGridColumn-derived column object in the DataGridColumnCollection collection. If the specified DataGridColumn-derived column object is not found, an index of -1 is returned.

The following code example demonstrates how to use the IndexOf method to determine the index of a DataGridColumn-derived object in a 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) 
      {

         Label1.Text = "The indexes of the columns: <br /><br />";

         foreach(DataGridColumn column in ItemsGrid.Columns)
         {
            Label1.Text += "<br />" + column.HeaderText + " = " + 
                      ItemsGrid.Columns.IndexOf(column);
         }
      }

   </script>

<head runat="server">
    <title>DataGridColumnCollection IndexOf Example</title>
</head>
<body>

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

      <h3>DataGridColumnCollection IndexOf 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>

      <br />
      <br />

      <asp:Button id="Button1"
           Text="Display Index of Columns"
           OnClick="Button_Click"
           runat="server"/>

      <br /><br />

      <asp:Label id="Label1"
           runat="server"/>

   </form>

</body>
</html>
   

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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