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
"State"] = i+1;
"State"] = 100;
"<script language='JavaScript' type='text/javascript'>\n");
sbScript.Append("<!--\n");
//需要IE5.5以上支持
sbScript.Append("window.showModalDialog('Progress.aspx','','dialogHeight: 100px; dialogWidth: 350px; edge: Raised; center: Yes; help: No; resizable: No; status: No;scroll:No;');\n");
//IE5.5以下使用window.open
//sbScript.Append("window.open('Progress.aspx','', 'height=100, width=350, toolbar =no, menubar=no, scrollbars=no, resizable=no, location=no, status=no');\n");
sbScript.Append("// -->\n");
sbScript.Append("</script>\n");
Page.RegisterClientScriptBlock("OpenProgressBar", sbScript.ToString());
"State"]=1;
OpenProgressBar(this.Page);
"_self">
<body MS_POSITIONING="GridLayout">
<form id="Form1" method="post" runat="server">
<asp:Label id="lblMessages" runat="server"></asp:Label>
<asp:Panel id="panelBarSide" runat="server" Width="300px" BorderStyle="Solid" BorderWidth="1px"
ForeColor="Silver">
<asp:Panel id="panelProgress" runat="server" Width="10px" BackColor="Green"></asp:Panel>
</asp:Panel>
<asp:Label id="lblPercent" runat="server" ForeColor="Blue"></asp:Label>
</form>
</body>
服务器端:
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;
namespace WebProgressBar
"State"]!=null)
"State"].ToString());
"State"]=0;
"Task undertaking!";
this.panelProgress.Width = state*30;
this.lblPercent.Text = state*10 + "%";
Page.RegisterStartupScript("","<script>window.setTimeout('window.Form1.submit()',100);</script>");
"Task Completed!";
Page.RegisterStartupScript("","<script>window.close();</script>");
}
}
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
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}
}