ICheckBoxControl.CheckedChanged Evento
Definizione
Importante
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Si verifica quando il valore della proprietà Checked cambia tra un invio e l'altro al server.
public:
event EventHandler ^ CheckedChanged;event EventHandler CheckedChanged;member this.CheckedChanged : EventHandler Event CheckedChanged As EventHandler Tipo evento
Esempio
CheckBox implementa ICheckBoxControl. Nell'esempio Checked di codice seguente viene illustrato come leggere il valore della proprietà e rispondere a un CheckedChanged evento.
<%@ Page Language="C#" AutoEventWireup="True" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>CheckBox CheckedChanged Example</title>
<script runat="server">
void Check_Clicked(Object sender, EventArgs e)
{
// Calculate the subtotal and display the result in currency format.
// Include tax if the check box is selected.
Message.Text = CalculateTotal(checkbox1.Checked).ToString("c");
}
void Page_Load(Object sender, EventArgs e)
{
// Display the subtotal without tax when the page is first loaded.
if(!IsPostBack)
{
// Calculate the subtotal and display the result in currency format.
Message.Text = CalculateTotal(false).ToString("c");
}
}
double CalculateTotal(bool Taxable)
{
// Calculate the subtotal for the example.
double Result = 1.99 + 2.99 + 3.99;
// Add tax, if applicable.
if(Taxable)
{
Result += Result * 0.086;
}
return Result;
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>CheckBox CheckedChanged Example</h3>
Select whether to include tax in the subtotal.
<br /><br />
<table border="1" cellpadding="5">
<tr>
<th colspan="2">
Shopping cart
</th>
</tr>
<tr>
<td>
Item 1
</td>
<td>
$1.99
</td>
</tr>
<tr>
<td>
Item 2
</td>
<td>
$2.99
</td>
</tr>
<tr>
<td>
Item 3
</td>
<td>
$3.99
</td>
</tr>
<tr>
<td>
<b>Subtotal</b>
</td>
<td>
<asp:Label id="Message" runat="server"/>
</td>
</tr>
<tr>
<td colspan="2">
<asp:CheckBox id="checkbox1" runat="server"
AutoPostBack="True"
Text="Include 8.6% sales tax"
TextAlign="Right"
OnCheckedChanged="Check_Clicked"/>
</td>
</tr>
</table>
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>CheckBox CheckedChanged Example</title>
<script runat="server">
Sub Check_Clicked(sender As Object, e As EventArgs)
' Calculate the subtotal and display the result in currency format.
' Include tax if the check box is selected.
Message.Text = CalculateTotal(checkbox1.Checked).ToString("c")
End Sub
Sub Page_Load(sender As Object, e As EventArgs)
' Display the subtotal without tax when the page is first loaded.
If Not IsPostBack Then
' Calculate the subtotal and display the result in currency format.
Message.Text = CalculateTotal(false).ToString("c")
End If
End Sub
Function CalculateTotal(Taxable As Boolean) As Double
' Calculate the subtotal for the example.
Dim Result As Double = 1.99 + 2.99 + 3.99
' Add tax, if applicable.
If(Taxable)
Result += Result * 0.086
End If
Return Result
End Function
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>CheckBox CheckedChanged Example</h3>
Select whether to include tax in the subtotal.
<br /><br />
<table border="1" cellpadding="5">
<tr>
<th colspan="2">
Shopping cart
</th>
</tr>
<tr>
<td>
Item 1
</td>
<td>
$1.99
</td>
</tr>
<tr>
<td>
Item 2
</td>
<td>
$2.99
</td>
</tr>
<tr>
<td>
Item 3
</td>
<td>
$3.99
</td>
</tr>
<tr>
<td>
<b>Subtotal</b>
</td>
<td>
<asp:Label id="Message" runat="server"/>
</td>
</tr>
<tr>
<td colspan="2">
<asp:CheckBox id="checkbox1" runat="server"
AutoPostBack="True"
Text="Include 8.6% sales tax"
TextAlign="Right"
OnCheckedChanged="Check_Clicked"/>
</td>
</tr>
</table>
</form>
</body>
</html>
Commenti
L'evento CheckedChanged viene generato quando il valore delle Checked modifiche tra i post nel server.
Si applica a
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