ASP.NET 2.0实现AJAX的Web开发(2)

System.Web.UI.ICallbackEventHandler{ private int PercentCompleted{ get { if System.Web.HttpContext.Current.Session["PercentComplete"] == null) { System.Web.HttpContext.Current.Session["PercentComplete"] = 1; } else { System.Web.HttpContext.Current.Session["PercentComplete"] =(int)System.Web.HttpContext.Current.Session["PercentComplete"] + 1; } return (int)System.Web.HttpContext.Current.Session["PercentComplete"]; } set { System.Web.HttpContext.Current.Session["PercentComplete"] = 1; } } public string RaiseCallbackEvent(string eventArguments) { int percent = this.PercentCompleted; if (percent ＞ 100) { this.PercentCompleted = 1; return "completed"; } else { return percent.ToString() + "%"; } } protected override void OnPreRender(EventArgs e) { this.Page.ClientScript.RegisterClientScriptBlock(typeof(ProgressBar)， [摘要]列表1ProgressBar.cspublicclassProgressBar:System.Web.UI.Control。

true); base.OnPreRender(e); } protected override void Render(HtmlTextWriter writer) { System.Text.StringBuilder sb = new StringBuilder(); sb.Append(@"＜tableProgressBarContainer"" bgcolor=""LightSteelBlue"" border=""0""400""DISPLAY:none; POSITION: absolute; Z-INDEX: 10""＞"); sb.Append(@"＜tr＞＜td colspan=""3""padding:3px 2px 2px 10px""＞"); sb.Append(@"＜font face=""Verdana， "UpdateProgressBar"， ""); js.Replace("##InitiateCallBack##"， ""， Helvetica， fp); reader.Close(); return js.ToString(); } ＝ ， this.GetClientSideScript()，System.Web.UI.ICallbackEventHandler{privateintPercentCompleted{get{ifSystem.Web.HttpCont 列表1 ProgressBar.cs public class ProgressBar : System.Web.UI.Control， "ProgressBar"， Arial， sans-serif"" size=""2""＞"); sb.Append(@"＜spanProgressBarLabel""＞Uploading...＜/span＞"); sb.Append(@"＜/font＞＜/td＞＜/tr＞＜tr＞＜td＞"); sb.Append(@"＜font size=""1""＞ ＜/font＞＜/td＞＜td bgcolor=""#999999"" width=""100%""＞"); sb.Append(@"＜tableProgressBar""0""0"" cellspacing=""0""＞"); sb.Append(@"＜tr＞＜tdbackground-image:url(progressbar.gif)""＞ ＜font size=""1""＞ ＜/font＞＜/td＞"); sb.Append(@"＜/tr＞＜/table＞＜/td＞"); sb.Append(@"＜td＞＜font size=""1""＞ ＜/font＞＜/td＞＜/tr＞"); sb.Append(@"＜tr5px""＞＜td colspan=""3""＞＜/td＞＜/tr＞"); sb.Append(@"＜/table＞"); writer.Write(sb.ToString()); base.Render(writer); } private string GetClientSideScript() { System.Reflection.Assembly dll = System.Reflection.Assembly.GetExecutingAssembly(); StreamReader reader; reader = new StreamReader(dll.GetManifestResourceStream("ProgressBar.txt")); StringBuilder js = new StringBuilder(reader.ReadToEnd()); string fp = this.Page.ClientScript.GetCallbackEventReference(this，。