DataGridColumnCollection.CopyTo(Array, Int32) 方法

定义

DataGridColumnCollection 集合中的项复制到指定的 Array,从 Array 中的指定索引处开始。

public:
 virtual void CopyTo(Array ^ array, int index);
public void CopyTo (Array array, int index);
abstract member CopyTo : Array * int -> unit
override this.CopyTo : Array * int -> unit
Public Sub CopyTo (array As Array, index As Integer)

参数

array
Array

一个从零开始的 Array,它接收 DataGridColumnCollection 的复制项。

index
Int32

指定的 Array 中接收复制内容的第一个位置。

实现

例外

arraynull

示例

下面的代码示例演示如何使用 CopyTo 方法将集合的内容 DataGridColumnCollection 复制到对象的数组 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">
 
      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 (!IsPostBack) 
         {
            // Load this data only once.
            ItemsGrid.DataSource= CreateDataSource();
            ItemsGrid.DataBind();
         }

      }

       void Button_Click(Object sender, EventArgs e) 
      {
       
         DataGridColumn[] myArray = new DataGridColumn[3];

         ItemsGrid.Columns.CopyTo(myArray, 0);

         Label1.Text = "The heading text for the items in the array are: <br /><br />";

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

      } 
   
   </script>
 
<head runat="server">
    <title>DataGridColumnCollection CopyTo Example</title>
</head>
<body>
 
   <form id="form1" runat="server">
 
      <h3>DataGridColumnCollection CopyTo Example</h3>
 
      <b>Product List</b>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           AutoGenerateColumns="false"
           runat="server">

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

      <br />

      <asp:Button id="Button1"
           Text="Copy DataGridColumnsCollection to Array"
           OnClick="Button_Click"
           runat="server"/>

      <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">
 
        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 Not IsPostBack Then
                ' Load this data only once.
                ItemsGrid.DataSource = CreateDataSource()
                ItemsGrid.DataBind()
            End If
        End Sub 'Page_Load
         

        Sub Button_Click(sender As Object, e As EventArgs)
            
            Dim myArray(3) As DataGridColumn
            
            ItemsGrid.Columns.CopyTo(myArray, 0)
            
            Label1.Text = "The heading text for the items in the array are: " & "<br />" & "<br />"
            
            Dim column As DataGridColumn
            For Each column In  myArray
                Label1.Text &= column.HeaderText & "<br />"
            Next column 
        End Sub 'Button_Click
   </script>
 
<head runat="server">
    <title>DataGridColumnCollection CopyTo Example</title>
</head>
<body>
 
   <form id="form1" runat="server">
 
      <h3>DataGridColumnCollection CopyTo Example</h3>
 
      <b>Product List</b>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           AutoGenerateColumns="false"
           runat="server">

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

      <br />

      <asp:Button id="Button1"
           Text="Copy DataGridColumnsCollection to Array"
           OnClick="Button_Click"
           runat="server"/>

      <br />

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

注解

使用此方法将集合的内容 DataGridColumnCollection 复制到指定的 中,从指定的 System.Array索引处开始。

备注

参数 array 必须是从零开始的 System.Array

适用于

另请参阅