public static Image GetImageByBytes(byte[] bytes)
{
Image photo = null;
using (MemoryStream ms = new MemoryStream(bytes))
{
ms.Write(bytes, 0, bytes.Length);
photo = Image.FromStream(ms, true);
}

return photo;
}
public static byte[] GetByteImage(Image img)
{
byte[] bt = null;
if (!img.Equals(null))
{
using (MemoryStream mostream = new MemoryStream())
{
Bitmap bmp = new Bitmap(img);
bmp.Save(mostream, System.Drawing.Imaging.ImageFormat.Jpeg);//将图像以指定的格式存入缓存内存流
bt = new byte[mostream.Length];
mostream.Position = 0;//设置留的初始位置
mostream.Read(bt, 0, Convert.ToInt32(bt.Length));
}
}
return bt;
}

 

//生成缩略图  (图片、宽、高，模式)

public static Image MakeThumbnail(Image img, int width, int height, string mode)
{
if (img == null) return null;
Image originalImage = img.Clone() as Image;
int towidth = width;
int toheight = height;

int x = 0;
int y = 0;
int ow = originalImage.Width;
int oh = originalImage.Height;

switch (mode)
{
case "HW":
break;
case "W":
toheight = originalImage.Height * width / originalImage.Width;
break;
case "H":
towidth = originalImage.Width * height / originalImage.Height;
break;
case "Cut":
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;
}
System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
try
{
g.Clear(System.Drawing.Color.Transparent);
g.DrawImage(originalImage, new System.Drawing.Rectangle(0, 0, towidth, toheight), new System.Drawing.Rectangle(x, y, ow, oh), System.Drawing.GraphicsUnit.Pixel);
return bitmap;
}
catch
{
return null;
}
finally
{
originalImage.Dispose();
g.Dispose();
}
}