CheckBoxField Constructor
Definition
Important
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Initializes a new instance of the CheckBoxField class.
public:
CheckBoxField();public CheckBoxField ();Public Sub New ()Examples
The following code example demonstrates how to use the constructor to dynamically add a CheckBoxField object to a GridView control.
<%@ 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 Page_Load(Object sender, EventArgs e)
{
// The columns need to be created only the first time
// the page is loaded.
if(!IsPostBack)
{
// Dynamically create columns to display the desired
// fields from the data source. Columns that are
// dynamically added to the GridView control are not persisted
// across posts and must be recreated each time the page is
// loaded.
// Create a BoundField object to display an author's last name.
BoundField lastNameBoundField = new BoundField();
lastNameBoundField.DataField = "au_lname";
lastNameBoundField.HeaderText = "Last Name";
// Create a CheckBoxField object to indicate whether the author
// is on contract.
CheckBoxField contractCheckBoxField = new CheckBoxField();
contractCheckBoxField.DataField = "contract";
contractCheckBoxField.HeaderText = "Contract";
// Add the columns to the Columns collection of the
// GridView control.
AuthorsGridView.Columns.Add(lastNameBoundField);
AuthorsGridView.Columns.Add(contractCheckBoxField);
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>CheckBoxField Constructor Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>CheckBoxField Constructor Example</h3>
<asp:gridview id="AuthorsGridView"
datasourceid="AuthorsSqlDataSource"
autogeneratecolumns="False"
runat="server">
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Pubs sample database. -->
<asp:sqldatasource id="AuthorsSqlDataSource"
selectcommand="SELECT [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
connectionstring="server=localhost;database=pubs;integrated security=SSPI"
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 Page_Load(sender as Object, e As EventArgs)
' The columns need to be created only the first time
' the page is loaded.
If Not IsPostBack Then
' Dynamically create columns to display the desired
' fields from the data source. Columns that are
' dynamically added to the GridView control are not persisted
' across posts and must be recreated each time the page is
' loaded.
' Create a BoundField object to display an author's last name.
Dim lastNameBoundField As BoundField = New BoundField
lastNameBoundField.DataField = "au_lname"
lastNameBoundField.HeaderText = "Last Name"
' Create a CheckBoxField object to indicate whether the author
' is on contract.
Dim contractCheckBoxField As CheckBoxField = New CheckBoxField
contractCheckBoxField.DataField = "contract"
contractCheckBoxField.HeaderText = "Contract"
' Add the columns to the Columns collection of the
' GridView control.
AuthorsGridView.Columns.Add(lastNameBoundField)
AuthorsGridView.Columns.Add(contractCheckBoxField)
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>CheckBoxField Constructor Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>CheckBoxField Constructor Example</h3>
<asp:gridview id="AuthorsGridView"
datasourceid="AuthorsSqlDataSource"
autogeneratecolumns="False"
runat="server">
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Pubs sample database. -->
<asp:sqldatasource id="AuthorsSqlDataSource"
selectcommand="SELECT [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
connectionstring="server=localhost;database=pubs;integrated security=SSPI"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
Remarks
Use this constructor to initialize a new instance of the CheckBoxField class. This constructor is commonly used when adding fields to a dynamically created data-bound control.
To dynamically add a CheckBoxField object to a data-bound control, create a new CheckBoxField object, set its properties, and then add it to the data-bound control's field collection. For example, if you are using the GridView control, add the CheckBoxField object to the Columns collection.
Note
Although you can dynamically add fields to a data-bound control, it is strongly recommended that all fields be statically declared and then shown or hidden, as appropriate. Statically declaring all your fields reduces the size of the view state for the parent data-bound control.
