CommandField Oluşturucu
Tanım
Önemli
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CommandField sınıfının yeni bir örneğini başlatır.
public:
CommandField();public CommandField ();Public Sub New ()Örnekler
Aşağıdaki kod örneği, bir denetime dinamik olarak alan CommandField sütunu GridView eklemek için oluşturucunun nasıl kullanılacağını gösterir.
<%@ 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)
{
// Dynamically generated field columns need to be created only
// the first time the page is loaded.
if (!IsPostBack)
{
// Create a CommandField object to display a Select button
// for each record in the GridView control.
CommandField selectCommandField = new CommandField();
selectCommandField.ShowSelectButton = true;
selectCommandField.SelectText = "Select Company";
// Create a BoundField object to display the company names.
BoundField lastNameBoundField = new BoundField();
lastNameBoundField.DataField = "au_lname";
lastNameBoundField.HeaderText = "Last Name";
// Create a BoundField object to display a customer's company name.
BoundField nameBoundField = new BoundField();
nameBoundField.DataField = "CompanyName";
nameBoundField.HeaderText = "Company Name";
// Create a BoundField object to display a customer's city.
BoundField cityBoundField = new BoundField();
cityBoundField.DataField = "City";
cityBoundField.HeaderText = "City";
// Add the field columns to the ColumnFields collection of the
// GridView control.
CustomersGridView.Columns.Add(selectCommandField);
CustomersGridView.Columns.Add(nameBoundField);
CustomersGridView.Columns.Add(cityBoundField);
}
}
void CustomersGridView_SelectedIndexChanged(Object sender, EventArgs e)
{
// Get the value of the company name and city from the appropriate cells.
String companyName = CustomersGridView.SelectedRow.Cells[1].Text;
String city = CustomersGridView.SelectedRow.Cells[2].Text;
Message.Text = "You selected " + companyName + " located in " + city + ".";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>CommandField Constructor Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>CommandField Constructor Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSqlDataSource"
autogeneratecolumns="False"
onselectedindexchanged="CustomersGridView_SelectedIndexChanged"
runat="server">
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:sqldatasource id="CustomersSqlDataSource"
selectcommand="Select [CustomerID], [CompanyName], [City] From [Customers]"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
<%@ Page language="VB" AutoEventWireup="False" %>
<!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(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
' Dynamically generated field columns need to be created only
' the first time the page is loaded.
If Not IsPostBack Then
' Create a CommandField object to display a Select button
' for each record in the GridView control.
Dim selectCommandField As New CommandField()
selectCommandField.ShowSelectButton = True
selectCommandField.SelectText = "Select Company"
' Create a BoundField object to display the company names.
Dim lastNameBoundField As New BoundField()
lastNameBoundField.DataField = "au_lname"
lastNameBoundField.HeaderText = "Last Name"
' Create a BoundField object to display a customer's company name.
Dim nameBoundField As New BoundField()
nameBoundField.DataField = "CompanyName"
nameBoundField.HeaderText = "Company Name"
' Create a BoundField object to display a customer's city.
Dim cityBoundField As New BoundField()
cityBoundField.DataField = "City"
cityBoundField.HeaderText = "City"
' Add the field columns to the ColumnFields collection of the
' GridView control.
CustomersGridView.Columns.Add(selectCommandField)
CustomersGridView.Columns.Add(nameBoundField)
CustomersGridView.Columns.Add(cityBoundField)
End If
End Sub
Sub CustomersGridView_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs) Handles CustomersGridView.SelectedIndexChanged
' Get the value of the company name and city from the appropriate cells.
Dim companyName As String = CustomersGridView.SelectedRow.Cells(1).Text
Dim city As String = CustomersGridView.SelectedRow.Cells(2).Text
Message.Text = "You selected " & companyName & " located in " & city & "."
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>CommandField Constructor Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>CommandField Constructor Example</h3>
<asp:label id="Message"
forecolor="Red"
runat="server"/>
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSqlDataSource"
autogeneratecolumns="False"
runat="server">
</asp:gridview>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:sqldatasource id="CustomersSqlDataSource"
selectcommand="Select [CustomerID], [CompanyName], [City] From [Customers]"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
Açıklamalar
Sınıfının yeni bir örneğini başlatmak için bu oluşturucuyu CommandField kullanın. Bu oluşturucu, dinamik olarak oluşturulan bir veriye bağlı denetime alan eklerken yaygın olarak kullanılır.
Veriye bağlı denetime dinamik olarak alan CommandField eklemek için yeni CommandField bir nesne oluşturun, özelliklerini ayarlayın ve sonra veriye bağlı denetimin alan koleksiyonuna ekleyin. Örneğin, denetimi kullanıyorsanız GridView nesnesini koleksiyona Columns ekleyinCommandField.
Not
Veriye bağlı denetime dinamik olarak alanlar ekleyebilmenize rağmen, alanların statik olarak bildirilmesi ve ardından uygun şekilde gösterilmesi veya gizlenmeleri önemle önerilir. Tüm alanlarınızın statik olarak bildirilmesi, üst veriye bağlı denetimin görünüm durumunun boyutunu küçültür.