ASP.NET 學習筆記_06 Httphandler

1、httphandler

        

執行個體1：通過產生一張動態圖片輸出用戶端的IP地址、作業系統類型、瀏覽器類型

<%@ WebHandler Language="C#" Class="visitor" %>using System;using System.Web;public class visitor : IHttpHandler {    public void ProcessRequest(HttpContext context)    {        context.Response.ContentType = "image/JPEG";        using (System.Drawing.Bitmap bitImage = new System.Drawing.Bitmap(330, 300))        {            //設定畫布            using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitImage))            {                //IP                g.DrawString("IP:" + context.Request.UserHostAddress, new System.Drawing.Font("宋體", 20), System.Drawing.Brushes.Red, new System.Drawing.PointF(0, 0));                //作業系統                g.DrawString("作業系統:" + context.Request.Browser.Platform, new System.Drawing.Font("宋體", 20), System.Drawing.Brushes.Red, new System.Drawing.PointF(0, 50));                //瀏覽器                g.DrawString("瀏覽器:" + context.Request.Browser.Type, new System.Drawing.Font("宋體", 20), System.Drawing.Brushes.Red, new System.Drawing.PointF(0, 100));            }            //儲存到輸出資料流中            bitImage.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);        }    }     public bool IsReusable {        get {            return false;        }    }}

執行個體2：通過“下載”串連，彈出使用者附件儲存

html代碼：<a href="dowload.ashx">下載</a>

<%@ WebHandler Language="C#" Class="dowload" %>using System;using System.Web;public class dowload : IHttpHandler {    public void ProcessRequest(HttpContext context)    {        string fileName = HttpUtility.UrlEncode("悲劇.jpg");        context.Response.ContentType = "image/JPEG";        //開啟附件對話方塊  報文頭header和設定它的值        context.Response.AddHeader("Content-Disposition", "attachment:filename=" + fileName);        context.Response.WriteFile("蘋果.jpg");           }     public bool IsReusable {        get {            return false;        }    }}