学步园

private System.Drawing.Image GetImage(string path)<br /> {<br /> if (path.StartsWith("http"))<br /> {<br /> System.Net.WebRequest request = System.Net.WebRequest.Create(path);<br /> request.Timeout = 10000;<br /> System.Net.HttpWebResponse httpresponse = (System.Net.HttpWebResponse)request.GetResponse();<br /> Stream s = httpresponse.GetResponseStream();<br /> return System.Drawing.Image.FromStream(s);<br /> }<br /> else<br /> {<br /> return System.Drawing.Image.FromFile(path);<br /> }<br /> }</p> <p> public void CreateImageOutput(int width, int height, string oPath, string tPath)<br /> {<br /> Image img = GetImage(oPath);<br /> Bitmap originalBmp = null;// new Bitmap(oPath);<br /> originalBmp = new Bitmap(img); img.Dispose();<br /> // 源图像在新图像中的位置<br /> int left, top;<br /> if (originalBmp.Width <= width && originalBmp.Height <= height)<br /> {<br /> // 原图像的宽度和高度都小于生成的图片大小<br /> left = (int)Math.Round((decimal)(width - originalBmp.Width) / 2);<br /> top = (int)Math.Round((decimal)(height - originalBmp.Height) / 2);<br /> // 最终生成的图像<br /> Bitmap bmpOut = new Bitmap(width, height);<br /> using (Graphics graphics = Graphics.FromImage(bmpOut))<br /> {<br /> // 设置高质量插值法<br /> graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;<br /> // 清空画布并以白色背景色填充<br /> graphics.Clear(Color.White);<br /> //加上边框<br /> //Pen pen = new Pen(ColorTranslator.FromHtml("#cccccc"));<br /> // graphics.DrawRectangle(pen, 0, 0, width - 1, height - 1);<br /> // 把源图画到新的画布上<br /> graphics.DrawImage(originalBmp, left, top);<br /> }<br /> bmpOut.Save(tPath);//保存为文件，tpath 为要保存的路径<br /> //this.OutputImgToPage(bmpOut);//直接输出到页面<br /> bmpOut.Dispose();<br /> originalBmp.Dispose();<br /> return;<br /> }</p> <p> // 新图片的宽度和高度，如400*200的图像，想要生成160*120的图且不变形，<br /> // 那么生成的图像应该是160*80，然后再把160*80的图像画到160*120的画布上<br /> int newWidth, newHeight;<br /> if (width * originalBmp.Height < height * originalBmp.Width)<br /> {<br /> newWidth = width;<br /> newHeight = (int)Math.Round((decimal)originalBmp.Height * width / originalBmp.Width);<br /> // 缩放成宽度跟预定义的宽度相同的，即left=0，计算top<br /> left = 0;<br /> top = (int)Math.Round((decimal)(height - newHeight) / 2);<br /> }<br /> else<br /> {<br /> newWidth = (int)Math.Round((decimal)originalBmp.Width * height / originalBmp.Height);<br /> newHeight = height;<br /> // 缩放成高度跟预定义的高度相同的，即top=0，计算left<br /> left = (int)Math.Round((decimal)(width - newWidth) / 2);<br /> top = 0;<br /> }<br /> // 生成按比例缩放的图，如：160*80的图<br /> Bitmap bmpOut2 = new Bitmap(newWidth, newHeight);<br /> using (Graphics graphics = Graphics.FromImage(bmpOut2))<br /> {<br /> graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;<br /> graphics.FillRectangle(Brushes.White, 0, 0, newWidth, newHeight);<br /> graphics.DrawImage(originalBmp, 0, 0, newWidth, newHeight);<br /> }<br /> // 再把该图画到预先定义的宽高的画布上，如160*120<br /> Bitmap lastbmp = new Bitmap(width, height);<br /> using (Graphics graphics = Graphics.FromImage(lastbmp))<br /> {<br /> // 设置高质量插值法<br /> graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;<br /> // 清空画布并以白色背景色填充<br /> graphics.Clear(Color.White);<br /> //加上边框<br /> //Pen pen = new Pen(ColorTranslator.FromHtml("#cccccc"));<br /> //graphics.DrawRectangle(pen, 0, 0, width - 1, height - 1);<br /> // 把源图画到新的画布上<br /> graphics.DrawImage(bmpOut2, left, top);<br /> }<br /> lastbmp.Save(tPath);//保存为文件，tpath 为要保存的路径<br /> //this.OutputImgToPage(lastbmp);//直接输出到页面<br /> lastbmp.Dispose();<br /> originalBmp.Dispose();<br /> }</p> <p> //private void OutputImgToPage(System.Drawing.Bitmap bmp)<br /> //{<br /> // //输出到页面<br /> // MemoryStream ms = new MemoryStream();<br /> // bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);<br /> // Response.ClearContent(); //需要输出图象信息 要修改HTTP头<br /> // byte[] buffer = ms.ToArray();<br /> // Response.AddHeader("Content-type", "image/jpeg");<br /> // Response.BinaryWrite(buffer);<br /> // bmp.Dispose();<br /> //}

调用：

s.CreateImageOutput(660, 840, "http://xxx,jpg", Server.MapPath("~/Upload/byyh/Pimg/d/fdsafas.jpg"));