Timer.Enabled 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。
public:
property bool Enabled { bool get(); void set(bool value); };
public bool Enabled { get; set; }
member this.Enabled : bool with get, set
Public Property Enabled As Boolean
屬性值
如果 Timer 將要初始化回傳作業,則為 true,否則為 false。 預設值是 true。
範例
下列範例顯示一個 UpdatePanel 控制項,顯示隨機產生的股票價格,以及產生股票價格的時間。 根據預設, Timer 控制項會每隔 10 秒更新控制項中 UpdatePanel 的內容。 使用者可以決定每隔 10 秒、每 60 秒更新股票價格,或完全不更新。 當使用者決定不要更新股票價格時, Enabled 屬性會設定為 false 。
<%@ Page Language="C#" AutoEventWireup="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>Timer Example Page</title>
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
OriginalTime.Text = DateTime.Now.ToLongTimeString();
}
protected void Timer1_Tick(object sender, EventArgs e)
{
StockPrice.Text = GetStockPrice();
TimeOfPrice.Text = DateTime.Now.ToLongTimeString();
}
private string GetStockPrice()
{
double randomStockPrice = 50 + new Random().NextDouble();
return randomStockPrice.ToString("C");
}
protected void RadioButton1_CheckedChanged(object sender, EventArgs e)
{
Timer1.Enabled = true;
Timer1.Interval = 10000;
}
protected void RadioButton2_CheckedChanged(object sender, EventArgs e)
{
Timer1.Enabled = true;
Timer1.Interval = 60000;
}
protected void RadioButton3_CheckedChanged(object sender, EventArgs e)
{
Timer1.Enabled = false;
}
</script>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:Timer ID="Timer1" OnTick="Timer1_Tick" runat="server" Interval="10000" />
<asp:UpdatePanel ID="StockPricePanel" runat="server" UpdateMode="Conditional">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Timer1" />
</Triggers>
<ContentTemplate>
Stock price is <asp:Label id="StockPrice" runat="server"></asp:Label><BR />
as of <asp:Label id="TimeOfPrice" runat="server"></asp:Label>
<br />
</ContentTemplate>
</asp:UpdatePanel>
<div>
<br />
Update stock price every:<br />
<asp:RadioButton ID="RadioButton1" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="10 seconds" OnCheckedChanged="RadioButton1_CheckedChanged" /><br />
<asp:RadioButton ID="RadioButton2" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="60 seconds" OnCheckedChanged="RadioButton2_CheckedChanged" /><br />
<asp:RadioButton ID="RadioButton3" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="Never" OnCheckedChanged="RadioButton3_CheckedChanged" />
<br />
Page loaded at <asp:Label ID="OriginalTime" runat="server"></asp:Label>
</div>
</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 id="Head1" runat="server">
<title>Timer Example Page</title>
<script runat="server">
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
OriginalTime.Text = DateTime.Now.ToLongTimeString()
End Sub
Protected Sub Timer1_Tick(ByVal sender As Object, ByVal e As EventArgs)
StockPrice.Text = GetStockPrice()
TimeOfPrice.Text = DateTime.Now.ToLongTimeString()
End Sub
Private Function GetStockPrice() As String
Dim randomStockPrice As Double = 50 + New Random().NextDouble()
Return randomStockPrice.ToString("C")
End Function
Protected Sub RadioButton1_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
Timer1.Interval = 10000
Timer1.Enabled = True
End Sub
Protected Sub RadioButton2_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
Timer1.Interval = 60000
Timer1.Enabled = True
End Sub
Protected Sub RadioButton3_CheckedChanged(ByVal sender As Object, ByVal e As System.EventArgs)
Timer1.Enabled = False
End Sub
</script>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<asp:Timer ID="Timer1" OnTick="Timer1_Tick" runat="server" Interval="10000" />
<asp:UpdatePanel ID="StockPricePanel" runat="server" UpdateMode="Conditional">
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Timer1" />
</Triggers>
<ContentTemplate>
Stock price is <asp:Label id="StockPrice" runat="server"></asp:Label><BR />
as of <asp:Label id="TimeOfPrice" runat="server"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
<div>
<asp:RadioButton ID="RadioButton1" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="10 seconds" OnCheckedChanged="RadioButton1_CheckedChanged" /><br />
<asp:RadioButton ID="RadioButton2" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="60 seconds" OnCheckedChanged="RadioButton2_CheckedChanged" /><br />
<asp:RadioButton ID="RadioButton3" AutoPostBack="true" GroupName="TimerFrequency" runat="server" Text="Never" OnCheckedChanged="RadioButton3_CheckedChanged" /><br />
<br />
Page originally created at <asp:Label ID="OriginalTime" runat="server"></asp:Label>
</div>
</form>
</body>
</html>
備註
Enabled使用 屬性來開啟 Timer 和關閉控制項。 當您設定 Enabled 為 true 時, Timer 控制項會在網頁轉譯時啟動其計時器倒數倒數。
在回傳時,您可以變更 屬性中的 Enabled 屬性值,而變更會在網頁內容轉譯于瀏覽器中時反映。 如果您變更 Enabled 屬性,然後在相同的回傳期間將它變更回其原始值,控制項 Timer 就會執行,就像未進行任何變更一樣。