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,0,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 = 0;
 mstream.Read(byData, 0, 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);  
}