有时候我们生成的图片并不需要保存到磁盘中,而是直接输出到页面,比如验证码、实时报表等,如何做呢?请参考如下:
protected void Page_Load(object sender, EventArgs e)
{
System.Drawing.Bitmap img = new System.Drawing.Bitmap(300, 100);
System.Drawing.Graphics graphics = System.Drawing.Graphics.FromImage(img);
System.Drawing.Font font = new System.Drawing.Font("宋体", 16); //字体与大小
System.Drawing.Brush brush = new System.Drawing.SolidBrush(System.Drawing.Color.Red);
graphics.DrawString("www.cftea.com", font, brush, 50, 50); //写字,最后两个参数表示位置
//将图片保存到内存流中
System.IO.MemoryStream stream = new System.IO.MemoryStream();
img.Save(stream, System.Drawing.Imaging.ImageFormat.Gif);
//在页面上输出
Response.Clear();
Response.ContentType = "image/gif";
Response.BinaryWrite(stream.ToArray());
stream.Close();
stream.Dispose();
graphics.Dispose();
img.Dispose();
Response.End();
}
{
System.Drawing.Bitmap img = new System.Drawing.Bitmap(300, 100);
System.Drawing.Graphics graphics = System.Drawing.Graphics.FromImage(img);
System.Drawing.Font font = new System.Drawing.Font("宋体", 16); //字体与大小
System.Drawing.Brush brush = new System.Drawing.SolidBrush(System.Drawing.Color.Red);
graphics.DrawString("www.cftea.com", font, brush, 50, 50); //写字,最后两个参数表示位置
//将图片保存到内存流中
System.IO.MemoryStream stream = new System.IO.MemoryStream();
img.Save(stream, System.Drawing.Imaging.ImageFormat.Gif);
//在页面上输出
Response.Clear();
Response.ContentType = "image/gif";
Response.BinaryWrite(stream.ToArray());
stream.Close();
stream.Dispose();
graphics.Dispose();
img.Dispose();
Response.End();
}
更简单的做法
img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif);
Response.ContentType = "image/gif";
Response.AddHeader("Content-Disposition", "inline;filename=1.gif");
Response.ContentType = "image/gif";
Response.AddHeader("Content-Disposition", "inline;filename=1.gif");
直接保存在 Response.OutputStream 中。最后一句 AddHeader 的目的是让用户在图片上右键另存为的时候,在保存文件对话框中指定默认的文件名。