倒数计时器避免回发ASP.NET VB [英] Countdown timer avoiding postback ASP.NET VB
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问题描述
有谁能让我知道这段代码有什么问题？我将它从C＃切换到vb并且它在c＃中没有任何错误工作我希望将计时器放在网络表单中而不是使用回发或单击按钮重置
default.aspx
Can anyone let me know what is wrong with this code? I switched it from C# to vb and it works without any mistakes in c# i want to place timer in web form and not reset with postback or click button
default.aspx
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<style type="text/css">
#CountDownPanel {color: blue; background-color: yellow; font-size: 18px;}
</style>
<asp:Label ID="Label1" runat="server" Text="Time Remaining:"></asp:Label>
<span id="CountDownPanel" runat="server"></span>
<asp:HiddenField ID="TotalSeconds" runat="server" Value="2700" />
</div>
</form>
</body>
</html>
default.aspx.vb
default.aspx.vb
Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Public Class _Default
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
If Not IsPostBack Then
NoCache(HttpContext.Current)
End If
End Sub
Protected Sub Page_PreRender(ByVal sender As Object, ByVal e As EventArgs)
If Page.IsPostBack Then
Dim ticks As Long = Convert.ToInt64(Me.StartTicks)
Dim startTime As DateTime = New DateTime(ticks)
Dim elapsed As TimeSpan = (startTime.AddMinutes(180) - DateTime.Now)
Me.TotalSeconds.Value = Convert.ToInt32(elapsed.TotalSeconds).ToString()
End If
ClientScript.RegisterClientScriptInclude("script", "CountDown.js")
End Sub
Private ReadOnly Property StartTicks As String
Get
Dim startTicksString As String = CType(Session("StartTicks"), String)
If String.IsNullOrEmpty(startTicksString) Then
startTicksString = DateTime.Now.Ticks.ToString()
Session("StartTicks") = startTicksString
End If
Return startTicksString
End Get
End Property
Private Sub NoCache(ByVal context As HttpContext)
context.Response.AddHeader("Pragma", "no-cache")
context.Response.CacheControl = "no-cache"
context.Response.Cache.SetAllowResponseInBrowserHistory(False)
context.Response.Cache.SetCacheability(HttpCacheability.NoCache)
context.Response.Cache.SetNoStore()
context.Response.Expires = -1
End Sub
End Class
countdown.js
countdown.js
var _countDowncontainer = 0;
var _currentSeconds = 0;
function ActivateCountDown(strContainerID, initialValue) {
_countDowncontainer = document.getElementById(strContainerID);
if (!_countDowncontainer) {
alert("count down error: container does not exist: " + strContainerID +
"\nmake sure html element with this ID exists");
return;
}
SetCountdownText(initialValue);
window.setTimeout("CountDownTick()", 1000);
}
function CountDownTick() {
if (_currentSeconds <= 0) {
alert("your time has expired!");
//document.getElementById("ctl01").disabled = true;
document.getElementById("ctl01").click();
return;
}
SetCountdownText(_currentSeconds - 1);
window.setTimeout("CountDownTick()", 1000);
}
function SetCountdownText(seconds) {
//store:
_currentSeconds = seconds;
//get minutes:
var minutes = parseInt(seconds / 60);
//shrink:
seconds = (seconds % 60);
//get hours:
var hours = parseInt(minutes / 60);
//shrink:
minutes = (minutes % 60);
//build text:
var strText = AddZero(hours) + ":" + AddZero(minutes) + ":" + AddZero(seconds);
//apply:
_countDowncontainer.innerHTML = strText;
}
function AddZero(num) {
return ((num >= 0) && (num < 10)) ? "0" + num : num + "";
}
window.onload = WindowLoad;
function WindowLoad(event) {
ActivateCountDown("CountDownPanel", document.getElementById("TotalSeconds").value);
}
我的尝试：
我用VB.NET尝试这个代码但不工作。我从C＃转发了它。它适用于C＃
What I have tried:
I TRY THIS CODE with VB.NET but NOT WORKING. I CONVERTed IT FROM C#. It works WITH C#
推荐答案
你没有说明帖子中有什么不起作用。看起来Page_PreRender没有触发器。你做的几件事。我认为＃1应该根据你的场景做到这一点。
1.将AutoEventWireup =false更改为AutoEventWireup =true
2.保留AutoEventWireup =false并更改方法
You didn't indicate what not working in the post. Look like the Page_PreRender did not get trigger. Couple of thing you do. I think #1 should do the trick based on your scenario.
1. Change the AutoEventWireup="false" to AutoEventWireup="true"
2. Leave the AutoEventWireup="false" and change the method
Protected Sub Page_PreRender(ByVal sender As Object, ByVal e As EventArgs)
End Sub
to
TO
Protected Overrides Sub OnPreRender(e As EventArgs)
MyBase.OnPreRender(e)
End Sub
asp.net - OnPreRender与Page_PreRender - Stack Overflow [ ^ ]
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