Timer.Enabled 属性
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
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
属性值
true。
示例
以下示例显示一个 UpdatePanel 控件,该控件显示随机生成的股票价格和生成股票价格的时间。 默认情况下,控件 Timer 每隔 10 秒更新控件中 UpdatePanel 的内容。 用户可以决定每 10 秒、每 60 秒或根本不更新股票价格。 当用户决定不更新股票价格时,该 Enabled 属性将设置为 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>
注解
使用 Enabled 属性打开 Timer 和关闭控件。 设置为 Enabled 该 true控件时,控件 Timer 将在呈现网页时启动其计时器倒计时。
在回发时,可以更改属性中的 Enabled 属性值,当网页内容在浏览器中呈现时,这些更改将反映。 如果更改属性 Enabled ,然后在相同的回发期间将其更改回其原始值,则 Timer 控件会运行,就好像没有进行更改一样。