图片和byte[]的互相转换

 //图片的"读"操作
 //①参数是图片路径:返回Byte[]类型:
 //参数是图片的路径
 public byte[] GetPictureData(string imagePath){
 FileStream fs=new FileStream(imagePath,FileMode.Open);
 byte[] byteData=new byte[fs.Length];
 fs.Read(byteData,,byteData.Length);
 fs.Close();
 return byteData();
 }
 //②参数类型是Image对象，返回Byte[]类型
 //将Image转换成流数据，并保存为byte[] 
 public byte[] PhotoImageInsert(System.Drawing.Image imgPhoto)
 {
  MemoryStream mstream = new MemoryStream();
  imgPhoto.Save(mstream, System.Drawing.Imaging.ImageFormat.Bmp);
  byte[] byData = new Byte[mstream.Length];
  mstream.Position = ;
  mstream.Read(byData, , byData.Length); mstream.Close();
  return byData;
 }
 //图片的“写”操作
 //①参数是Byte[]类型，返回值是Image对象
 public System.Drawing.Image ReturnPhoto(byte[] streamByte)
 {
  System.IO.MemoryStream ms = new System.IO.MemoryStream(streamByte);
  System.Drawing.Image img = System.Drawing.Image.FromStream(ms);
  return img;
 }
 //②参数是Byte[] 类型，没有返回值（ASP.NET输出图片）
 public void WritePhoto(byte[] streamByte)
 {
  // Response.ContentType 的默认值为默认值为“text/html”
  Response.ContentType = "image/GIF";
  //图片输出的类型有: image/GIF     image/JPEG
  Response.BinaryWrite(streamByte);
 }