//把
图片
---》 字节数组
MemoryStream mm=new MemoryStream();
this.pictureBox1.Image.Save(mm,this.pictureBox1.Image.RawFormat);
byte [] uu=mm.ToArray();
//图片读出来
byte[] uu = (dr[3] as byte[]);
MemoryStream ms=new MemoryStream(uu);
this.pictureBox1.Image = Image.FromStream(ms);