文件转为byte[]

FileStream fs = new FileStream(filepath, FileMode.Open, FileAccess.Read);
byte[] desBytes = new byte[fs.Length];
fs.Read(desBytes, 0, desBytes.Length);
fs.Close();

 

byte[]转换为BitmapImage:

public static BitmapImage ByteArrayToBitmapImage(byte[] byteArray) 
{
BitmapImage bmp = null;
try
{
bmp = new BitmapImage();
bmp.BeginInit();
bmp.StreamSource = new MemoryStream(byteArray);
bmp.EndInit();
}
catch
{
bmp = null;
}
return bmp;
}

BitmapImage转换为byte[]:

public static byte[] BitmapImageToByteArray(BitmapImage bmp) 
{
byte[] byteArray = null;
try
{
Stream sMarket = bmp.StreamSource;
if (sMarket != null && sMarket.Length > 0)
{
//很重要,因为Position经常位于Stream的末尾,导致下面读取到的长度为0。
sMarket.Position = 0;

using (BinaryReader br = new BinaryReader(sMarket))
{
byteArray = br.ReadBytes((int)sMarket.Length);
}
}
}
catch
{
//other exception handling
}
return byteArray;
}