DataGridColumnCollection 类
DataGridColumn 导出的列对象的集合，这些对象表示 DataGrid 控件中的列。无法继承此类。
**命名空间:**System.Web.UI.WebControls
**程序集:**System.Web（在 system.web.dll 中）
语法
声明
Public NotInheritable Class DataGridColumnCollection
Implements ICollection, IEnumerable, IStateManager
用法
Dim instance As DataGridColumnCollection
public sealed class DataGridColumnCollection : ICollection, IEnumerable, IStateManager
public ref class DataGridColumnCollection sealed : ICollection, IEnumerable, IStateManager
public final class DataGridColumnCollection implements ICollection, IEnumerable,
IStateManager
public final class DataGridColumnCollection implements ICollection, IEnumerable,
IStateManager
备注
使用 DataGridColumnCollection 集合可以以编程的方式管理 DataGridColumn 导出的列对象的集合。这些对象表示 DataGrid 控件中的列。可以在 DataGridColumnCollection 集合中添加列、移除列或插入列。
提示
当 AutoGenerateColumns 属性设置为 true 时，不向 Columns 集合中添加由 DataGrid 控件创建的列。
DataGrid 控件不将其 Columns 集合的内容存储到视图状态中。若要动态添加或移除列，必须在每次刷新页时以编程方式添加或移除该列。提供 Page_Init 函数，该函数在重新加载 DataGrid 控件的状态并重新生成该控件前添加或移除列。否则，对 Columns 集合所做的更改在显示 DataGrid 控件时不会反映出来。
提示
尽管可以通过编程方式在 DataGrid 控件的 Columns 集合中添加或移除列，但是，静态地列出相应列然后使用 Visible 属性显示或隐藏各列更简单一些。
集合中列的顺序确定在 DataGrid 控件中这些列的显示顺序。
下表列出了从 DataGridColumn 类导出的不同的列类。
列类 |
说明 |
|---|---|
绑定到数据源中字段的列。它以文本形式显示字段中的每个项。这是 DataGrid 控件的默认列类型。 |
|
一个列，该列显示列中各项的命令按钮。这使您可以创建一列自定义按钮控件，如“添加”按钮或“移除”按钮。 |
|
一个列，该列包含列中各项的编辑命令。 |
|
一个列，该列将列中各项作为超链接显示。列的内容可以绑定到数据源中的字段或静态文本。 |
|
一个列，该列根据指定的模板显示列中的各个项。这使您可以控制列的内容，例如显示图像。 |
提示
DataGridColumn 类是列出的列类的基类。它不在 DataGridColumnCollection 集合中直接使用。
示例
下面的代码示例演示了如何使用 DataGridColumnCollection 集合向 DataGrid 控件中动态添加列。请注意，DataGrid 控件的 Columns 属性是 DataGridColumnCollection 类的一个实例。
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<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 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 DataView = New DataView(dt)
Return dv
End Function
Sub Page_Load(sender As Object, e As EventArgs)
' Create a DataGrid control.
Dim ItemsGrid As DataGrid = New DataGrid()
' Set the properties of the DataGrid.
ItemsGrid.ID = "ItemsGrid"
ItemsGrid.BorderColor = System.Drawing.Color.Black
ItemsGrid.CellPadding = 3
ItemsGrid.AutoGenerateColumns = False
' Set the styles for the DataGrid.
ItemsGrid.HeaderStyle.BackColor = System.Drawing.Color.FromArgb(&H0000aaaa)
' Create the columns for the DataGrid control. The DataGrid
' columns are dynamically generated. Therefore, the columns
' must be re-created each time the page is refreshed.
' Create and add the columns to the collection.
ItemsGrid.Columns.Add(CreateBoundColumn("IntegerValue", "Item"))
ItemsGrid.Columns.Add( _
CreateBoundColumn("StringValue", "Description"))
ItemsGrid.Columns.Add( _
CreateBoundColumn("CurrencyValue", "Price", "{0:c}", _
HorizontalAlign.Right))
ItemsGrid.Columns.Add( _
CreateLinkColumn("http:'www.microsoft.com", "_self", _
"Microsoft", "Related link"))
' Specify the data source and bind it to the control.
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
' Add the DataGrid control to the Controls collection of
' the PlaceHolder control.
Place.Controls.Add(ItemsGrid)
End Sub
Function CreateBoundColumn(DataFieldValue As String, HeaderTextValue As String) As BoundColumn
' This version of CreateBoundColumn method sets only the
' DataField and HeaderText properties.
' Create a BoundColumn.
Dim column As BoundColumn = New BoundColumn()
' Set the properties of the BoundColumn.
column.DataField = DataFieldValue
column.HeaderText = HeaderTextValue
Return column
End Function
Function CreateBoundColumn(DataFieldValue As String, _
HeaderTextValue As String, FormatValue As String, _
AlignValue As HorizontalAlign) As BoundColumn
' This version of CreateBoundColumn method sets the DataField,
' HeaderText, and DataFormatString properties. It also sets the
' HorizontalAlign property of the ItemStyle property of the column.
' Create a BoundColumn using the overloaded CreateBoundColumn method.
Dim column As BoundColumn = CreateBoundColumn(DataFieldValue, HeaderTextValue)
' Set the properties of the BoundColumn.
column.DataFormatString = FormatValue
column.ItemStyle.HorizontalAlign = AlignValue
Return column
End Function
Function CreateLinkColumn(NavUrlValue As String, TargetValue As String, _
TextValue As String, HeaderTextValue As String) As HyperLinkColumn
' Create a BoundColumn.
Dim column As HyperLinkColumn = New HyperLinkColumn()
' Set the properties of the ButtonColumn.
column.href = NavUrlValue
column.Target = TargetValue
column.Text = TextValue
column.HeaderText = HeaderTextValue
Return column
End Function
</script>
<body>
<form runat=server>
<h3>DataGrid Constructor Example</h3>
<b>Product List</b>
<asp:PlaceHolder id="Place"
runat="server"/>
</form>
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<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 < 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)
{
// Create a DataGrid control.
DataGrid ItemsGrid = new DataGrid();
// Set the properties of the DataGrid.
ItemsGrid.ID = "ItemsGrid";
ItemsGrid.BorderColor = System.Drawing.Color.Black;
ItemsGrid.CellPadding = 3;
ItemsGrid.AutoGenerateColumns = false;
// Set the styles for the DataGrid.
ItemsGrid.HeaderStyle.BackColor =
System.Drawing.Color.FromArgb(0x0000aaaa);
// Create the columns for the DataGrid control. The DataGrid
// columns are dynamically generated. Therefore, the columns
// must be re-created each time the page is refreshed.
// Create and add the columns to the collection.
ItemsGrid.Columns.Add(CreateBoundColumn("IntegerValue", "Item"));
ItemsGrid.Columns.Add(
CreateBoundColumn("StringValue", "Description"));
ItemsGrid.Columns.Add(
CreateBoundColumn("CurrencyValue", "Price", "{0:c}",
HorizontalAlign.Right));
ItemsGrid.Columns.Add(
CreateLinkColumn("https://www.microsoft.com", "_self",
"Microsoft", "Related link"));
// Specify the data source and bind it to the control.
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
// Add the DataGrid control to the Controls collection of
// the PlaceHolder control.
Place.Controls.Add(ItemsGrid);
}
BoundColumn CreateBoundColumn(String DataFieldValue,
String HeaderTextValue)
{
// This version of the CreateBoundColumn method sets only the
// DataField and HeaderText properties.
// Create a BoundColumn.
BoundColumn column = new BoundColumn();
// Set the properties of the BoundColumn.
column.DataField = DataFieldValue;
column.HeaderText = HeaderTextValue;
return column;
}
BoundColumn CreateBoundColumn(String DataFieldValue,
String HeaderTextValue, String FormatValue,
HorizontalAlign AlignValue)
{
// This version of CreateBoundColumn method sets the DataField,
// HeaderText, and DataFormatString properties. It also sets the
// HorizontalAlign property of the ItemStyle property of the column.
// Create a BoundColumn using the overloaded CreateBoundColumn method.
BoundColumn column = CreateBoundColumn(DataFieldValue, HeaderTextValue);
// Set the properties of the BoundColumn.
column.DataFormatString = FormatValue;
column.ItemStyle.HorizontalAlign = AlignValue;
return column;
}
HyperLinkColumn CreateLinkColumn(String NavUrlValue,
String TargetValue, String TextValue, String HeaderTextValue)
{
// Create a BoundColumn.
HyperLinkColumn column = new HyperLinkColumn();
// Set the properties of the ButtonColumn.
column.href = NavUrlValue;
column.Target = TargetValue;
column.Text = TextValue;
column.HeaderText = HeaderTextValue;
return column;
}
</script>
<body>
<form runat=server>
<h3>DataGrid Constructor Example</h3>
<b>Product List</b>
<asp:PlaceHolder id="Place"
runat="server"/>
</form>
</body>
</html>
继承层次结构
System.Object
System.Web.UI.WebControls.DataGridColumnCollection
线程安全
此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。
平台
Windows 98、Windows 2000 SP4、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0
请参见
参考
DataGridColumnCollection 成员
System.Web.UI.WebControls 命名空间
DataGrid 类
DataGrid.Columns 属性
DataGridColumn 类
BoundColumn 类
ButtonColumn 类
EditCommandColumn
HyperLinkColumn
TemplateColumn