using System;
using System.Collections;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml.Linq;
using System.Drawing.Drawing2D;
using System.Drawing;
namespace AspTechnicalBase
{
??? /// <summary>
??? /// $codebehindclassname$ 的摘要说明
??? /// </summary>
??? [WebService(Namespace = "http://tempuri.org/")]
??? [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
??? public class DrawingOnWebPage : IHttpHandler
??? {??? /// <summary>
??????? /// 绘图的相关参数
??????? /// </summary>
??????? private const int ImageWidth = 600;
??????? private const int ImageHeight = 100;
??????? /// <summary>
??????? /// 响应HTTP请求
??????? /// </summary>
??????? /// <param name="context">HTTP请求的上下文对象</param>
??????? public void ProcessRequest(HttpContext context)
??????? {
??????????? //开辟一个ImageWidth像素宽、ImageHeight像素高的绘图缓冲区
??????????? Bitmap bmp = new Bitmap(ImageWidth,ImageHeight);
??????????? //创建绘图表面对象，引用这一绘图缓冲区
??????????? Graphics g = Graphics.FromImage(bmp);
??????????? //生成一个渐变的画刷
??????????? Brush br = new LinearGradientBrush(new Point(0,0),new Point(ImageWidth,Color.Black,Color.Blue);
??????????? //用渐变画刷填充绘图表面
??????????? g.FillRectangle(br,g.ClipBounds);
??????????? string str = "使用GDI+动态生成Web图像";
??????????? Font f = new Font("宋体",30);
??????????? //输出文字
??????????? g.DrawString(str,f,Brushes.Yellow,new PointF(40,20));
??????????? //将结果输出到浏览器
??????????? context.Response.ContentType = "Image/JPEG";
??????????? context.Response.Clear();
??????????? context.Response.BufferOutput = true;
??????????? bmp.Save(context.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);
??????????? //释放相关的绘图对象
??????????? br.Dispose();
??????????? f.Dispose();
??????????? g.Dispose();
??????????? bmp.Dispose();
??????? }
??????? /// <summary>
??????? /// 是否自动缓存此对象以供下次复用
??????? /// </summary>
??????? public bool IsReusable
??????? {
??????????? get
??????????? {
??????????????? return false;
??????????? }
??????? }
??? }
}
?
使用:
?
??? <form id="form1" runat="server">
??? <div>
??? <h2>使用一般处理程序绘制Web图像</h2>
??? <hr />
??? <img src="DrawingOnWebPage.ashx" alt="动态生成的GDI+图像" /> ??? </div> ??? </form>
