网上已经有很多Web进度条的例子,但是很多都是估算时间,不能正真反应任务的真实进度。我自己结合多线程和ShowModalDialog制做了一个实时进度条,原理很简单:使用线程开始长时间的任务,定义一个Session,当任务进行到不同的阶段改变Session的值,线程开始的同时使用ShowModalDialog打开一个进度条窗口,不断刷新这个窗口获取Session值,反应出实时的进度。下面就来看看具体的代码:(文章结尾处下载源代码)
先新建一个Default.aspx页面,
客户端代码:
<body MS_POSITIONING="GridLayout">
<form id="Form1" method="post" runat="server">
<br>
<br>
<asp:Button id="Button1" runat="server" Text="Start Long Task!"></asp:Button>
</form>
</body>
服务器端代码:
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Text;
namespace WebProgressBar
{
/**//// <summary>
/// Summary description for _Default.
/// </summary>
public class _Default : System.Web.UI.Page
{
protected System.Web.UI.WebControls.Button Button1;
private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here
}
Web Form Designer generated code#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeComponent();
base.OnInit(e);
}
/**//// <summary>
/// Required method for Designer support - do not modify
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