C# Stream 和 byte[] 之间的转换

/* - - - - - - - - - - - - - - - - - - - - - - - - 
 * Stream 和 byte[] 之间的转换
 * - - - - - - - - - - - - - - - - - - - - - - - */
///<summary>
/// 将 Stream 转成 byte[]
///</summary>
publicbyte[] StreamToBytes(Stream stream)
{
byte[] bytes =newbyte[stream.Length];
    stream.Read(bytes, 0, bytes.Length);
// 设置当前流的位置为流的开始
    stream.Seek(0, SeekOrigin.Begin);
return bytes;
}
///<summary>
/// 将 byte[] 转成 Stream
///</summary>
public Stream BytesToStream(byte[] bytes)
{
    Stream stream =new MemoryStream(bytes);
return stream;
}
/* - - - - - - - - - - - - - - - - - - - - - - - - 
 * Stream 和 文件之间的转换
 * - - - - - - - - - - - - - - - - - - - - - - - */
///<summary>
/// 将 Stream 写入文件
///</summary>
publicvoid StreamToFile(Stream stream,string fileName)
{
// 把 Stream 转换成 byte[]
byte[] bytes =newbyte[stream.Length];
    stream.Read(bytes, 0, bytes.Length);
// 设置当前流的位置为流的开始
    stream.Seek(0, SeekOrigin.Begin);
// 把 byte[] 写入文件
    FileStream fs =new FileStream(fileName, FileMode.Create);
    BinaryWriter bw =new BinaryWriter(fs);
    bw.Write(bytes);
    bw.Close();
    fs.Close();
}
///<summary>
/// 从文件读取 Stream
///</summary>
public Stream FileToStream(string fileName)
{            
// 打开文件
    FileStream fileStream =new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
// 读取文件的 byte[]
byte[] bytes =newbyte[fileStream.Length];
    fileStream.Read(bytes, 0, bytes.Length);
    fileStream.Close();
// 把 byte[] 转换成 Stream
    Stream stream =new MemoryStream(bytes);
return stream;
}