ButtonField 建構函式
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。
初始化 ButtonField 類別的新執行個體。
public:
ButtonField();public ButtonField ();Public Sub New ()範例
下列程式碼範例示範如何使用 M：System.Web.UI.WebControls.ButtonField.#ctor 建構函式，以動態方式將物件新增 ButtonField 至 GridView 控制項。
<%@ Page language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void CustomersGridView_RowCommand(Object sender, GridViewCommandEventArgs e)
{
// If multiple ButtonField column fields are used, use the
// CommandName property to determine which button was clicked.
if(e.CommandName=="Select")
{
// Convert the row index stored in the CommandArgument
// property to an Integer.
int index = Convert.ToInt32(e.CommandArgument);
// Get the last name of the selected Customer from the appropriate
// cell in the GridView control.
GridViewRow selectedRow = CustomersGridView.Rows[index];
TableCell contactCell = selectedRow.Cells[1];
string contact = contactCell.Text;
// Display the selected Customer.
Message.Text = "You selected " + contact + ".";
}
}
void Page_Load(Object sender, EventArgs e)
{
// The field columns need to be created only the first time
// the page is loaded.
if (!IsPostBack)
{
// Dynamically create field columns to display the desired
// fields from the data source.
// Create a ButtonField object to allow the user to
// select an Customer.
ButtonField selectButtonField = new ButtonField ();
selectButtonField.ButtonType = ButtonType.Button;
selectButtonField.CommandName = "Select";
selectButtonField.HeaderText = "Select Customer";
selectButtonField.Text = "Select";
// Create a BoundField object to display an Customer's last name.
BoundField contactNameBoundField = new BoundField();
contactNameBoundField.DataField = "ContactName";
contactNameBoundField.HeaderText = "Contact Name";
// Create a BoundField object to display an Customer's first name.
BoundField contactTitleBoundField = new BoundField();
contactTitleBoundField.DataField = "ContactTitle";
contactTitleBoundField.HeaderText = "Contact Title";
// Add the field columns to the Columns collection of the
// GridView control.
CustomersGridView.Columns.Add (selectButtonField);
CustomersGridView.Columns.Add(contactNameBoundField);
CustomersGridView.Columns.Add(contactTitleBoundField);
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ButtonField Constructor Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ButtonField Constructor Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"
AssociatedControlID="CustomersGridView"/>
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSqlDataSource"
autogeneratecolumns="False"
onrowcommand="CustomersGridView_RowCommand"
runat="server">
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. -->
<asp:sqldatasource id="CustomersSqlDataSource"
selectcommand="Select [CustomerID], [CompanyName], [ContactName], [ContactTitle] From [Customers]"
connectionstring="<%$ ConnectionStrings:NorthWindConnection%>"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
<%@ Page language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub CustomersGridView_RowCommand(ByVal sender As Object, ByVal e As GridViewCommandEventArgs)
' If multiple ButtonField column fields are used, use the
' CommandName property to determine which button was clicked.
If e.CommandName = "Select" Then
' Convert the row index stored in the CommandArgument
' property to an Integer.
Dim index As Integer = Convert.ToInt32(e.CommandArgument)
' Get the last name of the selected Customer from the appropriate
' cell in the GridView control.
Dim selectedRow As GridViewRow = CustomersGridView.Rows(index)
Dim contactNameCell As TableCell = selectedRow.Cells(1)
Dim contactName As String = contactNameCell.Text
' Display the selected Customer.
Message.Text = "You selected " & contactName & "."
End If
End Sub
Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
' The field columns need to be created only the first time
' the page is loaded.
If Not IsPostBack Then
' Dynamically create field columns to display the desired
' fields from the data source.
' Create a ButtonField object to allow the user to
' select an Customer.
Dim selectButtonField As New ButtonField
selectButtonField.ButtonType = ButtonType.Button
selectButtonField.CommandName = "Select"
selectButtonField.HeaderText = "Select Customer"
selectButtonField.Text = "Select"
' Create a BoundField object to display an Customer's last name.
Dim contactNameBoundField As New BoundField
contactNameBoundField.DataField = "ContactName"
contactNameBoundField.HeaderText = "Contact Name"
' Create a BoundField object to display an Customer's first name.
Dim contactTitleBoundField As New BoundField
contactTitleBoundField.DataField = "ContactTitle"
contactTitleBoundField.HeaderText = "Contact Title"
' Add the field columns to the Columns collection of the
' GridView control.
CustomersGridView.Columns.Add(selectButtonField)
CustomersGridView.Columns.Add(contactNameBoundField)
CustomersGridView.Columns.Add(contactTitleBoundField)
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ButtonField Constructor Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ButtonField Constructor Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"
AssociatedControlID="CustomersGridView"/>
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSqlDataSource"
autogeneratecolumns="False"
onrowcommand="CustomersGridView_RowCommand"
runat="server">
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. -->
<asp:sqldatasource id="CustomersSqlDataSource"
selectcommand="Select [CustomerID], [CompanyName], [ContactName], [ContactTitle] From [Customers]"
connectionstring="<%$ ConnectionStrings:NorthWindConnection%>"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
備註
使用 建 ButtonField 構函式來初始化 類別的新實例 ButtonField 。 這個建構函式通常會在將欄位新增至動態建立的資料繫結控制項時使用。
若要以動態方式將物件新增 ButtonField 至資料繫結控制項，請建立新的 ButtonField 物件、設定其屬性，然後將它新增至資料繫結控制項的欄位集合。 例如，如果您使用 GridView 控制項，請將 ButtonField 物件新增至 Columns 集合。
注意
雖然您可以動態將欄位新增至資料繫結控制項，但欄位應該以靜態方式宣告，然後視需要顯示或隱藏。 以靜態方式宣告所有欄位會減少父系資料繫結控制項的檢視狀態大小。