HttpHandler动态生成图片

string path = context.Server.MapPath("~/1.jpg");//获取服务器上的图片并转换为本地路径
//显示到输出流中
using (Stream instream = File.OpenRead(path))
{
    instream.CopyTo(context.Response.OutputStream);
}

string name = context.Request["name"];//name的值可以动态的输入
using (Bitmap bmp = new Bitmap(500, 500))//创建一个尺寸为500*500的内存图片
using (Graphics g = Graphics.FromImage(bmp))//得到图片的画布
{
    g.DrawString(name, new Font(FontFamily.GenericSerif, 30), Brushes.Red, 0, 0);//Font应该被释放
    g.DrawEllipse(Pens.Green, 100, 100, 100, 100);
    bmp.Save(context.Response.OutputStream, ImageFormat.Jpeg);//图片保存到输出流            
} 

context.Response.ContentType = "image/jpeg";
using (Bitmap bmp = new Bitmap(500, 200))//创建一个尺寸为500*500的内存图片
using (Graphics g = Graphics.FromImage(bmp))//得到图片的画布
using (Font font = new Font(FontFamily.GenericSerif, 30))
{
    HttpRequest request = context.Request;
    g.DrawString("IP:" + request.UserHostAddress, font, Brushes.Red, 0, 0);
    g.DrawString("浏览器:" + request.Browser.Browser + request.Browser.Version, font, Brushes.Red, 0, 50);
    g.DrawString("操作系统:" + request.Browser.Platform, font, Brushes.Red, 0, 100);
    bmp.Save(context.Response.OutputStream, ImageFormat.Jpeg);//图片保存到输出流
}

context.Response.ContentType = "image/jpeg";
string name = context.Request["name"];
string imgFullPath = context.Server.MapPath("~/PaoNiuZheng.jpg");
using (Image bmp = Bitmap.FromFile(imgFullPath))
using (Graphics g = Graphics.FromImage(bmp))//得到图片的画布
using (Font font1 = new Font(FontFamily.GenericSerif, 12))
using (Font font2 = new Font(FontFamily.GenericSerif, 5))
{
    {
        g.DrawString(name, font1, Brushes.Black, 125, 220);//Font应该被释放
        g.DrawString(name, font2, Brushes.Black, 309, 50);//Font应该被释放
        bmp.Save(context.Response.OutputStream, ImageFormat.Jpeg);//图片保存到输出流
    }
}

Random name = new Random();
int r = name.Next(999, 9999);
using (Bitmap bmp = new Bitmap(100, 50))//创建一个尺寸为500*500的内存图片
using (Graphics g = Graphics.FromImage(bmp))//得到图片的画布
{
    g.DrawString(r.ToString(), new Font(FontFamily.GenericSerif, 30), Brushes.Red, 0, 0);//Font应该被释放
    g.DrawEllipse(Pens.Green, 100, 100, 100, 100);
    bmp.Save(context.Response.OutputStream, ImageFormat.Jpeg);//图片保存到输出流            
}