Question

C# 我已经将二进制转化为图片，请问如何设置图片的尺寸。

System.IO.MemoryStream ms = new System.IO.MemoryStream(streamByte);
System.Drawing.Image img = System.Drawing.Image.FromStream(ms);
img.Save("e:\\Server\\SampImag.jpg");
已经生成图片，如和设置图片的尺寸，请结合我的代码。

Answer 1

先加入下面的方法，然后把你最后一行改为

MakeThumbnail(img,"e:\\Server\\SampImag.jpg",200,200,"W");//200是你要的图片大小，其它参数含义自己看

public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode)
 {
Image originalImage = Image.FromFile(originalImagePath);
MakeThumbnail(originalImage,thumbnailPath,width,height,mode);
}
public static void MakeThumbnail(Image img, string thumbnailPath, int width, int height, string mode)
        {
            Image originalImage = img;
            
            int towidth = width;
            int toheight = height;
        
            int x = 0;
            int y = 0;
            int ow = originalImage.Width;
            int oh = originalImage.Height;        
            switch (mode)
            {        
                case "HW"://指定高宽缩放（可能变形）                
                    break;
                case "W"://指定宽，高按比例                    
                    toheight = originalImage.Height * width/originalImage.Width;
                    break;
                case "H"://指定高，宽按比例
                    towidth = originalImage.Width * height/originalImage.Height;                    
                    break;        
                case "Cut"://指定高宽裁减（不变形）                
                    if((double)originalImage.Width/(double)originalImage.Height > (double)towidth/(double)toheight)
                    {
                        oh = originalImage.Height;
                        ow = originalImage.Height*towidth/toheight;
                        y = 0;
                        x = (originalImage.Width - ow)/2;
                    }
                    else
                    {
                        ow = originalImage.Width;
                        oh = originalImage.Width*height/towidth;
                        x = 0;
                        y = (originalImage.Height - oh)/2;
                    }
                    break;                    
                default :
                    break;
            }    
            
            //新建一个bmp图片
            Image bitmap = new System.Drawing.Bitmap(towidth,toheight);
            //新建一个画板
            Graphics g = System.Drawing.Graphics.FromImage(bitmap);
            //设置高质量插值法
            g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
            //设置高质量,低速度呈现平滑程度
            g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
            //清空画布并以透明背景色填充
            g.Clear(Color.Transparent);        
            //在指定位置并且按指定大小绘制原图片的指定部分
            g.DrawImage(originalImage, new Rectangle(0, 0, towidth, toheight), 
                new Rectangle(x, y, ow,oh),
                GraphicsUnit.Pixel);
            try
            {            
                //以jpg格式保存缩略图
                bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
            }
            catch(System.Exception e)
            {
                throw e;
            }
            finally
            {
                originalImage.Dispose();
                bitmap.Dispose();                        
                g.Dispose();
            }
        }

追问

太给力了！我已经测试了，解决了我的问题！谢谢！

Answer 2

保存的时候何必设置尺寸？显示的时候设置就得了

追问

呵呵，这话让你说的，既然我要设置当然有设置的原因！

追答

保存的图片也根本没有尺寸，只有像素，而且取决于你还原的img

追问

呵呵 你看看其他人的回答吧！