CheckBox.Checked 屬性
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
取得或設定值，指出是否已選取 CheckBox 控制項。
public:
virtual property bool Checked { bool get(); void set(bool value); };[System.ComponentModel.Bindable(true)]
public virtual bool Checked { get; set; }[System.ComponentModel.Bindable(true, System.ComponentModel.BindingDirection.TwoWay)]
[System.Web.UI.Themeable(false)]
public virtual bool Checked { get; set; }[<System.ComponentModel.Bindable(true)>]
member this.Checked : bool with get, set[<System.ComponentModel.Bindable(true, System.ComponentModel.BindingDirection.TwoWay)>]
[<System.Web.UI.Themeable(false)>]
member this.Checked : bool with get, setPublic Overridable Property Checked As Boolean屬性值
指示已選取的狀態，為 true，否則為 false。 預設為 false。
實作
- 屬性
範例
下列範例示範如何使用 Checked 屬性來判斷控制項的狀態 CheckBox 。
注意
下列程式碼範例會使用單一檔案程式碼模型，如果直接複製到程式碼後置檔案，可能無法正常運作。 此程式碼範例必須複製到副檔名為 .aspx 的空白文字檔中。 如需Web Form程式碼模型的詳細資訊，請參閱ASP.NET Web Forms頁碼模型。
<%@ 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>
備註
使用這個屬性來判斷是否已 CheckBox 檢查控制項。 這個屬性也可以用來以程式設計方式設定控制項的狀態 CheckBox 。
這個屬性無法由佈景主題或樣式表主題設定。 如需詳細資訊，請參閱 ThemeableAttribute 和ASP.NET 主題和麵板。