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
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()

{
this.Button1.Click += new System.EventHandler(this.Button1_Click);
this.Load += new System.EventHandler(this.Page_Load);

}
#endregion

private void LongTask()

{
//模拟长时间任务
//每个循环模拟任务进行到不同的阶段
for(int i=0;i<11;i++)

{
System.Threading.Thread.Sleep(1000);
//设置每个阶段的state值,用来显示当前的进度
Session["State"] = i+1;
}
//任务结束
Session["State"] = 100;

}

public static void OpenProgressBar(System.Web.UI.Page Page)

{
StringBuilder sbScript = new StringBuilder();

sbScript.Append("<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());
}

private void Button1_Click(object sender, System.EventArgs e)

{
System.Threading.Thread thread=new System.Threading.Thread(new System.Threading.ThreadStart(LongTask));
thread.Start();

Session["State"]=1;
OpenProgressBar(this.Page);
}
}
}
新建一个进度条页面Progress.aspx
客户端:
在head中加入<base target="_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

{

/**//// <summary>
/// Summary description for Progress.
/// </summary>
public class Progress : System.Web.UI.Page

{
protected System.Web.UI.WebControls.Label lblMessages;
protected System.Web.UI.WebControls.Panel panelProgress;
protected System.Web.UI.WebControls.Panel panelBarSide;
protected System.Web.UI.WebControls.Label lblPercent;
private int state = 0;
private void Page_Load(object sender, System.EventArgs e)

{
// Put user code to initialize the page here
if(Session["State"]!=null)

{
state = Convert.ToInt32(Session["State"].ToString());
}
else

{
Session["State"]=0;
}
if(state>0&&state<=10)

{
this.lblMessages.Text = "Task undertaking!";
this.panelProgress.Width = state*30;
this.lblPercent.Text = state*10 + "%";
Page.RegisterStartupScript("","<script>window.setTimeout('window.Form1.submit()',100);</script>");
}
if(state==100)

{
this.panelProgress.Visible = false;
this.panelBarSide.Visible = false;
this.lblMessages.Text = "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
}
}
源代码下载:
WebProgressBar.rar