FormViewCommandEventArgs.CommandSource Eigenschap
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Hiermee haalt u het besturingselement op dat de gebeurtenis heeft gegenereerd.
public:
property System::Object ^ CommandSource { System::Object ^ get(); };public object CommandSource { get; }member this.CommandSource : objPublic ReadOnly Property CommandSource As ObjectWaarde van eigenschap
Een Object die het besturingselement vertegenwoordigt dat de gebeurtenis heeft gegenereerd.
Voorbeelden
In het volgende voorbeeld ziet u hoe u de CommandSource eigenschap gebruikt voor toegang tot de eigenschappen van het knopbesturingselement dat de ItemCommand gebeurtenis heeft gegenereerd.
Important
Dit voorbeeld heeft een tekstvak dat gebruikersinvoer accepteert. Dit is een mogelijke beveiligingsrisico. Standaard valideren ASP.NET webpagina's dat gebruikersinvoer geen script- of HTML-elementen bevat. Zie Overzicht van Script Exploits voor meer informatie.
<%@ 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 ProductFormView_ItemCommand(Object sender, FormViewCommandEventArgs e)
{
// The ItemCommand event is raised when any button within
// the FormView control is clicked. Use the CommandName property
// to determine which button was clicked.
if (e.CommandName == "Add")
{
// Add the product to the ListBox control.
// Use the Row property to retrieve the data row.
FormViewRow row = ProductFormView.Row;
// Retrieve the ProductNameLabel control from
// the data row.
Label productNameLabel = (Label)row.FindControl("ProductNameLabel");
// Retrieve the QuantityTextBox control from
// the data row.
TextBox quantityTextBox = (TextBox)row.FindControl("QuantityTextBox");
if (productNameLabel != null && quantityTextBox != null)
{
// Get the product name from the ProductNameLabel control.
string name = productNameLabel.Text;
// Get the quantity from the QuantityTextBox control.
string quantity = quantityTextBox.Text;
// Create the text to display in the ListBox control.
string description = name + " - " + quantity + " Qty";
// Create a ListItem object using the description and
// product name.
ListItem item = new ListItem(description, name);
// Add the ListItem object to the ListBox.
ProductListBox.Items.Add(item);
// Use the CommandSource property to retrieve
// the Add button. Disable the button after
// the user adds the currently displayed employee
// name to the ListBox control.
Button addButton = (Button)e.CommandSource;
addButton.Enabled = false;
}
}
}
void ProductFormView_DataBound(Object sender, EventArgs e)
{
// To prevent the user from adding duplicate items,
// disable the Add button if the item being bound to the
// FormView control is already in the ListBox control.
// Use the Row property to retrieve the data row.
FormViewRow row = ProductFormView.Row;
// Retrieve the Add button from the data row.
Button addButton = (Button)row.FindControl("AddButton");
// Retrieve the ProductNameLabel control from
// data row.
Label productNameLabel = (Label)row.FindControl("ProductNameLabel");
if (addButton != null && productNameLabel != null)
{
// Get the product name from the ProductNameLabel
// control.
string name = productNameLabel.Text;
// Use the FindByValue method to determine whether
// the ListBox control already contains an entry for
// the item.
ListItem item = ProductListBox.Items.FindByValue(name);
// Disable the Add button if the ListBox control
// already contains the item.
if (item != null)
{
addButton.Enabled = false;
}
else
{
addButton.Enabled = true;
}
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>FormViewCommandEventArgs Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>FormViewCommandEventArgs Example</h3>
<asp:formview id="ProductFormView"
datasourceid="ProductSource"
allowpaging="true"
datakeynames="ProductID"
onitemcommand="ProductFormView_ItemCommand"
ondatabound="ProductFormView_DataBound"
runat="server">
<itemtemplate>
<table>
<tr>
<td style="width:400px">
<b>Description:</b>
<asp:label id="ProductNameLabel"
text='<%# Eval("ProductName") %>'
runat='server'/>
<br/>
<b>Price:</b>
<asp:label id="PriceLabel"
text='<%# Eval("UnitPrice", "{0:c}") %>'
runat='server'/>
<br/>
<asp:textbox id="QuantityTextBox"
width="50px"
maxlength="3"
runat="server"/> Qty
</td>
</tr>
<tr>
<td>
<asp:requiredfieldvalidator ID="QuantityRequiredValidator"
controltovalidate="QuantityTextBox"
text="Please enter a quantity."
display="Static"
runat="server"/>
<br/>
<asp:CompareValidator id="QuantityCompareValidator"
controltovalidate="QuantityTextBox"
text="Please enter an integer value."
display="Static"
type="Integer"
operator="DataTypeCheck"
runat="server"/>
</td>
</tr>
<tr>
<td colspan="2">
<asp:button id="AddButton"
text="Add"
commandname="Add"
runat="server"/>
</td>
</tr>
</table>
</itemtemplate>
</asp:formview>
<br/><br/><hr/>
Items:<br/>
<asp:listbox id="ProductListBox"
runat="server"/>
<!-- 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="ProductSource"
selectcommand="Select [ProductID], [ProductName], [UnitPrice] From [Products]"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</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 ProductFormView_ItemCommand(ByVal sender As Object, ByVal e As FormViewCommandEventArgs)
' The ItemCommand event is raised when any button within
' the FormView control is clicked. Use the CommandName property
' to determine which button was clicked.
If e.CommandName = "Add" Then
' Add the product to the ListBox control.
' Use the Row property to retrieve the data row.
Dim row As FormViewRow = ProductFormView.Row
' Retrieve the ProductNameLabel control from
' the data row.
Dim productNameLabel As Label = CType(row.FindControl("ProductNameLabel"), Label)
' Retrieve the QuantityTextBox control from
' the data row.
Dim quantityTextBox As TextBox = CType(row.FindControl("QuantityTextBox"), TextBox)
If productNameLabel IsNot Nothing And quantityTextBox IsNot Nothing Then
' Get the product name from the ProductNameLabel control.
Dim name As String = productNameLabel.Text
' Get the quantity from the QuantityTextBox control.
Dim quantity As String = quantityTextBox.Text
' Create the text to display in the ListBox control.
Dim description As String = name & " - " & quantity & " Qty"
' Create a ListItem object using the description and
' product name.
Dim item As new ListItem(description, name)
' Add the ListItem object to the ListBox.
ProductListBox.Items.Add(item)
' Use the CommandSource property to retrieve
' the Add button. Disable the button after
' the user adds the currently displayed employee
' name to the ListBox control.
Dim addButton As Button = CType(e.CommandSource, Button)
addButton.Enabled = False
End If
End If
End Sub
Sub ProductFormView_DataBound(ByVal sender As Object, ByVal e As EventArgs)
' To prevent the user from adding duplicate items,
' disable the Add button if the item being bound to the
' FormView control is already in the ListBox control.
' Use the Row property to retrieve the data row.
Dim row As FormViewRow = ProductFormView.Row
' Retrieve the Add button from the data row.
Dim addButton As Button = CType(row.FindControl("AddButton"), Button)
' Retrieve the ProductNameLabel control from
' data row.
Dim productNameLabel As Label = CType(row.FindControl("ProductNameLabel"), Label)
If addButton IsNot Nothing And productNameLabel IsNot Nothing Then
' Get the product name from the ProductNameLabel
' control.
Dim name As String = productNameLabel.Text
' Use the FindByValue method to determine whether
' the ListBox control already contains an entry for
' the item.
Dim item As ListItem = ProductListBox.Items.FindByValue(name)
' Disable the Add button if the ListBox control
' already contains the item.
If item IsNot Nothing Then
addButton.Enabled = False
Else
addButton.Enabled = True
End If
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>FormViewCommandEventArgs Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>FormViewCommandEventArgs Example</h3>
<asp:formview id="ProductFormView"
datasourceid="ProductSource"
allowpaging="true"
datakeynames="ProductID"
onitemcommand="ProductFormView_ItemCommand"
ondatabound="ProductFormView_DataBound"
runat="server">
<itemtemplate>
<table>
<tr>
<td style="width:400px">
<b>Description:</b>
<asp:label id="ProductNameLabel"
text='<%# Eval("ProductName") %>'
runat='server'/>
<br/>
<b>Price:</b>
<asp:label id="PriceLabel"
text='<%# Eval("UnitPrice", "{0:c}") %>'
runat='server'/>
<br/>
<asp:textbox id="QuantityTextBox"
width="50px"
maxlength="3"
runat="server"/> Qty
</td>
</tr>
<tr>
<td>
<asp:requiredfieldvalidator ID="QuantityRequiredValidator"
controltovalidate="QuantityTextBox"
text="Please enter a quantity."
display="Static"
runat="server"/>
<br/>
<asp:CompareValidator id="QuantityCompareValidator"
controltovalidate="QuantityTextBox"
text="Please enter an integer value."
display="Static"
type="Integer"
operator="DataTypeCheck"
runat="server"/>
</td>
</tr>
<tr>
<td colspan="2">
<asp:button id="AddButton"
text="Add"
commandname="Add"
runat="server"/>
</td>
</tr>
</table>
</itemtemplate>
</asp:formview>
<br/><br/><hr/>
Items:<br/>
<asp:listbox id="ProductListBox"
runat="server"/>
<!-- 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="ProductSource"
selectcommand="Select [ProductID], [ProductName], [UnitPrice] From [Products]"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
Opmerkingen
Gebruik de CommandSource eigenschap voor toegang tot de eigenschappen van het besturingselement dat de gebeurtenis heeft gegenereerd. In het geval van een FormViewCommandEventArgs object is het besturingselement de knop waarop de gebruiker heeft geklikt.