DataGridColumnCollection.IndexOf(DataGridColumn) 方法

参考

定义

命名空间:: System.Web.UI.WebControls

程序集:: System.Web.dll

重要

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返回 DataGridColumn 集合中指定的、由 DataGridColumnCollection 导出的列对象的索引。

public:
 int IndexOf(System::Web::UI::WebControls::DataGridColumn ^ column);

public int IndexOf (System.Web.UI.WebControls.DataGridColumn column);

member this.IndexOf : System.Web.UI.WebControls.DataGridColumn -> int

Public Function IndexOf (column As DataGridColumn) As Integer

参数

column: DataGridColumn

要在 DataGridColumn 中搜索的由 DataGridColumnCollection 导出的列。

Int32

DataGridColumn 中指定的、由 DataGridColumnCollection 导出的列的索引位置。默认值为 -1，该值指示未找到指定的、由 DataGridColumn 导出的对象。

示例

下面的代码示例演示如何使用IndexOf该方法来确定集合中DataGridColumnCollection派生对象的索引DataGridColumn。

<%@ 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>

<%@ 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)
            
            Label1.Text = "The indexes of the columns: <br /><br />"
            
            Dim column As DataGridColumn
            For Each column In  ItemsGrid.Columns
                Label1.Text &= "<br />" & column.HeaderText & " = " & ItemsGrid.Columns.IndexOf(column)
            Next column
        End Sub 'Button_Click
 
   </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>

注解

使用此方法确定集合中DataGridColumnCollection指定DataGridColumn派生列对象的索引号。如果未找到指定的 DataGridColumn派生列对象，则返回索引 -1 。

适用于

通过

DataGridColumnCollection.IndexOf(DataGridColumn) 方法

定义

参数

返回

示例

注解

适用于

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