ASP.NET笔记之 Httphandler的操作详解

1、httphandler

实例1：通过生成一张动态图片输出客户端的IP地址、操作系统类型、浏览器类型

<%@ 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))
 {
 //设置画布
 using (System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitImage))
 {
 //IP
 g.DrawString("IP:" + context.Request.UserHostAddress, new System.Drawing.Font("宋体", 20), System.Drawing.Brushes.Red, new System.Drawing.PointF(0, 0));
 //操作系统
 g.DrawString("操作系统:" + context.Request.Browser.Platform, new System.Drawing.Font("宋体", 20), System.Drawing.Brushes.Red, new System.Drawing.PointF(0, 50));
 //浏览器
 g.DrawString("浏览器:" + context.Request.Browser.Type, new System.Drawing.Font("宋体", 20), System.Drawing.Brushes.Red, new System.Drawing.PointF(0, 100));
 }
 //保存到输出流中
 bitImage.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
 }
 } public bool IsReusable {
 get {
 return false;
 }
 }
}

html代码：<a rel="nofollow noopener noreferrer" href="dowload.ashx">下载</a>

<%@ WebHandler Language="C#" Class="dowload" %>

using System;
using System.Web;
public class dowload : IHttpHandler {
 public void ProcessRequest(HttpContext context)
 {
 string fileName = HttpUtility.UrlEncode("悲剧.jpg");
 context.Response.ContentType = "image/JPEG";
 //打开附件对话框 报文头header和设置它的值
 context.Response.AddHeader("Content-Disposition", "attachment:filename=" + fileName);
 context.Response.WriteFile("苹果.jpg"); 
 } public bool IsReusable {
 get {
 return false;
 }
 }
}

本文ASP.NET笔记之 Httphandler的操作详解到此结束。成功的关键在于相信自己有成功的能力。小编再次感谢大家对我们的支持！