ButtonField Konstruktor
Definition
Viktigt
En del information gäller för förhandsversionen av en produkt och kan komma att ändras avsevärt innan produkten blir allmänt tillgänglig. Microsoft lämnar inga garantier, uttryckliga eller underförstådda, avseende informationen som visas här.
Initierar en ny instans av ButtonField klassen.
public:
ButtonField();public ButtonField();Public Sub New ()Exempel
Följande kodexempel visar hur du använder konstruktorn M:System.Web.UI.WebControls.ButtonField.#ctor för att lägga till ett ButtonField objekt dynamiskt i en GridView kontroll.
<%@ 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>
Kommentarer
ButtonField Använd konstruktorn för att initiera en ny instans av ButtonField klassen. Den här konstruktorn används ofta när du lägger till fält i en dynamiskt skapad databunden kontroll.
Om du vill lägga till ett ButtonField objekt dynamiskt i en databunden kontroll skapar du ett nytt ButtonField objekt, anger dess egenskaper och lägger sedan till det i fältsamlingen för den databundna kontrollen. Om du till exempel använder GridView kontrollen lägger du till objektet ButtonField i Columns samlingen.
Note
Även om du kan lägga till fält dynamiskt i en databunden kontroll bör fälten deklareras statiskt och sedan visas eller döljas efter behov. Om du statiskt deklarerar alla fält minskar storleken på visningstillståndet för den överordnade databundna kontrollen.
