DataGrid.Columns 屬性
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
取得表示 DataGrid 控制項資料行的物件的集合。
public:
virtual property System::Web::UI::WebControls::DataGridColumnCollection ^ Columns { System::Web::UI::WebControls::DataGridColumnCollection ^ get(); };[System.Web.UI.PersistenceMode(System.Web.UI.PersistenceMode.InnerProperty)]
public virtual System.Web.UI.WebControls.DataGridColumnCollection Columns { get; }[<System.Web.UI.PersistenceMode(System.Web.UI.PersistenceMode.InnerProperty)>]
member this.Columns : System.Web.UI.WebControls.DataGridColumnCollectionPublic Overridable ReadOnly Property Columns As DataGridColumnCollection屬性值
DataGridColumnCollection 物件，包含表示 DataGrid 控制項資料行的物件的集合。
- 屬性
範例
下列程式碼範例示範如何使用 Columns 集合，以動態方式將資料行新增至 DataGrid 控制項。
<%@ 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 Page_Init(Object sender, EventArgs e)
{
// Create a dynamic column to add to Columns collection.
BoundColumn NumberColumn = new BoundColumn();
NumberColumn.HeaderText="Item Number";
NumberColumn.DataField="IntegerValue";
// Add column to Columns collection.
ItemsGrid.Columns.AddAt(2, NumberColumn);
}
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();
}
</script>
<head runat="server">
<title>DataGrid Columns Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid Columns 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"
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>
</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 Page_Init(sender As Object, e As EventArgs)
' Create a dynamic column to add to Columns collection.
Dim NumberColumn As New BoundColumn()
NumberColumn.HeaderText = "Item Number"
NumberColumn.DataField = "IntegerValue"
' Add column to Columns collection.
ItemsGrid.Columns.AddAt(2, NumberColumn)
End Sub 'Page_Init
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
</script>
<head runat="server">
<title>DataGrid Columns Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid Columns 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"
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>
</form>
</body>
</html>
<%@ 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 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 < 5; 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)
{
// Load sample data only once, when the page is first loaded.
if (!IsPostBack)
{
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
}
void Button_Click(Object sender, EventArgs e)
{
// Count the number of selected items in the DataGrid control.
int count = 0;
// Display the selected times.
Message.Text = "You Selected: <br />";
// Iterate through each item (row) in the DataGrid control and
// determine whether it is selected.
foreach (DataGridItem item in ItemsGrid.Items)
{
DetermineSelection(item, ref count);
}
// If no items are selected, display the appropriate message.
if (count == 0)
{
Message.Text = "No items selected";
}
}
void DetermineSelection(DataGridItem item, ref int count)
{
// Retrieve the SelectCheckBox CheckBox control from the
// specified item (row) in the DataGrid control.
CheckBox selection = (CheckBox)item.FindControl("SelectCheckBox");
// If the item is selected, display the appropriate message and
// increment the count of selected items.
if (selection != null)
{
if (selection.Checked)
{
Message.Text += "- " + item.Cells[1].Text + "<br />";
count++;
}
}
}
void Check_Change(Object sender, EventArgs e)
{
// Show or hide the first column depending on the value of
// the check box.
if (ShowCheckBox.Checked)
{
ItemsGrid.Columns[0].Visible = true;
}
else
{
ItemsGrid.Columns[0].Visible = false;
}
}
</script>
<head runat="server">
<title>DataGridColumn Visible Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGridColumn Visible Example</h3>
Select whether to show or hide the first column.
<br /><br />
<b>Product List</b>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
ShowFooter="True"
AutoGenerateColumns="False"
runat="server">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<FooterStyle BackColor="#00aaaa">
</FooterStyle>
<Columns>
<asp:BoundColumn DataField="IntegerValue"
Visible="True"
HeaderText="Item"/>
<asp:BoundColumn DataField="StringValue"
Visible="True"
HeaderText="Description"/>
<asp:BoundColumn DataField="CurrencyValue"
Visible="True"
HeaderText="Price"
DataFormatString="{0:c}">
<ItemStyle HorizontalAlign="Right">
</ItemStyle>
</asp:BoundColumn>
<asp:TemplateColumn HeaderText="Select Item"
Visible="True" >
<ItemTemplate>
<asp:CheckBox id="SelectCheckBox"
Text="Add to Cart"
Checked="False"
runat="server"/>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
<br /><br />
<asp:Button id="SubmitButton"
Text="Submit"
OnClick = "Button_Click"
runat="server"/>
<br /><br />
<asp:Label id="Message"
runat="server"/>
<hr />
<asp:CheckBox id="ShowCheckBox"
Text="Show first column"
AutoPostBack="True"
OnCheckedChanged="Check_Change"
Checked="True"
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 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 4
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)
' Load sample data only once, when the page is first loaded.
If Not IsPostBack Then
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End If
End Sub
Sub Button_Click(sender As Object, e As EventArgs)
' Count the number of selected items in the DataGrid control.
Dim count As Integer = 0
' Display the selected times.
Message.Text = "You Selected: <br />"
' Iterate through each item (row) in the DataGrid control and
' determine whether it is selected.
Dim item As DataGridItem
For Each item In ItemsGrid.Items
DetermineSelection(item, count)
Next
' If no items are selected, display the appropriate message.
If count = 0 Then
Message.Text = "No items selected"
End If
End Sub
Sub DetermineSelection(item As DataGridItem, ByRef count As Integer)
' Retrieve the SelectCheckBox CheckBox control from the
' specified item (row) in the DataGrid control.
Dim selection As CheckBox = _
CType(item.FindControl("SelectCheckBox"), CheckBox)
' If the item is selected, display the appropriate message and
' increment the count of selected items.
If Not selection Is Nothing Then
If selection.Checked Then
Message.Text &= "- " & item.Cells(1).Text & "<br />"
count = count + 1
End If
End If
End Sub
Sub Check_Change(sender As Object, e As EventArgs)
' Show or hide the first column depending on the value of
' the check box.
If ShowCheckBox.Checked Then
ItemsGrid.Columns(0).Visible = True
Else
ItemsGrid.Columns(0).Visible = False
End If
End Sub
</script>
<head runat="server">
<title>DataGridColumn Visible Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGridColumn Visible Example</h3>
Select whether to show or hide the first column.
<br /><br />
<b>Product List</b>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
ShowFooter="True"
AutoGenerateColumns="False"
runat="server">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<FooterStyle BackColor="#00aaaa">
</FooterStyle>
<Columns>
<asp:BoundColumn DataField="IntegerValue"
Visible="True"
HeaderText="Item"/>
<asp:BoundColumn DataField="StringValue"
Visible="True"
HeaderText="Description"/>
<asp:BoundColumn DataField="CurrencyValue"
Visible="True"
HeaderText="Price"
DataFormatString="{0:c}">
<ItemStyle HorizontalAlign="Right">
</ItemStyle>
</asp:BoundColumn>
<asp:TemplateColumn HeaderText="Select Item"
Visible="True" >
<ItemTemplate>
<asp:CheckBox id="SelectCheckBox"
Text="Add to Cart"
Checked="False"
runat="server"/>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
<br /><br />
<asp:Button id="SubmitButton"
Text="Submit"
OnClick = "Button_Click"
runat="server"/>
<br /><br />
<asp:Label id="Message"
runat="server"/>
<hr />
<asp:CheckBox id="ShowCheckBox"
Text="Show first column"
AutoPostBack="True"
OnCheckedChanged="Check_Change"
Checked="True"
runat="server"/>
</form>
</body>
</html>
備註
使用這個屬性，以程式設計方式控制 控制項中的資料行 DataGrid 集合。 Columns集合包含在 控制項中轉譯的明確宣告資料 DataGrid 行。
注意
明確宣告的資料行可以與自動產生的資料行搭配使用。 同時使用這兩者時，會先轉譯明確宣告的資料行，後面接著自動產生的資料行。 自動產生的資料行不會新增至 Columns 集合。
資料行在 控制項中顯示的 DataGrid 順序是由資料行出現在集合中 Columns 的順序所控制。
下表顯示衍生自 DataGridColumn 類別的不同資料行類別，並可用於 Columns 集合中。
| 資料行類型 | 描述 |
|---|---|
| BoundColumn | 顯示系結至資料來源中欄位的資料行。 它會將欄位中的每個專案顯示為文字。 這是 控制項的預設資料行類型 DataGrid 。 |
| ButtonColumn | 顯示資料行中每個專案的命令按鈕。 這可讓您建立自訂按鈕控制項的資料行，例如 Add 或 Remove 按鈕。 |
| EditCommandColumn | 顯示資料行，其中包含資料行中每個專案的編輯命令。 |
| HyperLinkColumn | 將資料行中每個專案的內容顯示為超連結。 資料行的內容可以系結至資料來源或靜態文字中的欄位。 |
| TemplateColumn | 在指定範本之後的資料行中顯示每個專案。 這可讓您在 資料行中提供自訂控制項。 |
