<%@ WebHandler Language="C#" Class="SavePhoto" %>   using System; using System.Web; using System.IO; using System.Drawing;   public class SavePhoto : IHttpHandler {     public void ProcessRequest(HttpContext context)     {         //System.Web.UI.Page page = new System.Web.UI.Page();           context.Response.ContentType = "text/plain";           if (context.Request.Form["PHeight"] != null && context.Request.Form["PWidth"] != null && context.Request.Form["strBMP"] != null)         {             try            {                 int height = int.Parse(context.Request.Form["PHeight"].ToString());                 int width = int.Parse(context.Request.Form["PWidth"].ToString());                 string strBmp = context.Request.Form["strBMP"].ToString();                 SaveBmp(BuildBitmap(width, height, strBmp), context.Server.MapPath("../../../images/CameraPhoto"));                   //System.Web.HttpContext.Current.Response.Write("<script>alert('111');</script>");                 context.Response.Write("RetMsg=true");               }             catch (Exception)             {                 context.Response.Write("RetMsg=false");             }         }     }

我想在这里上传成功后,写提示框体,却无法实现...
   //System.Web.HttpContext.Current.Response.Write("<script>alert('111');</script>");
                context.Response.Write("RetMsg=true");
就是这样使用，只是Response.Write只是传出流的意思，没法马上执行。这个JS代码，只有服务端执行完了，传送到客服端，才会被执行 写提示框体？
System.Web.HttpContext.Current.Response.Write("<script>alert('111');</script>");
改成
Page.ClientScript.RegisterStartupScript(GetType(),"","<script>alert('111');</script>");
看 int height = int.Parse(context.Request.Form["PHeight"].ToString());                 int width = int.Parse(context.Request.Form["PWidth"].ToString());                 string strBmp = context.Request.Form["strBMP"].ToString();                 SaveBmp(BuildBitmap(width, height, strBmp), context.Server.MapPath("../../../images/CameraPhoto"));                   //System.Web.HttpContext.Current.Response.Write("<script>alert('111');</script>");                 context.Response.Write("<h2 style='color:green'>保存文件成功</h2><hr />文件已经保存到服务器路径："+                        context.Server.MapPath("../../../images/CameraPhoto"));