C# Stream 和 byte[] 之間的轉換

/* - - - - - - - - - - - - - - - - - - - - - - - -
* Stream 和 byte[] 之間的轉換
* - - - - - - - - - - - - - - - - - - - - - - - */
/// <summary>
/// 將 Stream 轉成 byte[]
/// </summary>
public byte[] StreamToBytes(Stream stream)
{
byte[] bytes = new byte[stream.Length];
stream.Read(bytes, 0, bytes.Length);

// 設定當前流的位置為流的開始
stream.Seek(0, SeekOrigin.Begin);
return bytes;
}

/// <summary>
/// 將 byte[] 轉成 Stream
/// </summary>
public Stream BytesToStream(byte[] bytes)
{
Stream stream = new MemoryStream(bytes);
return stream;
}

/* - - - - - - - - - - - - - - - - - - - - - - - -
* Stream 和 檔案之間的轉換
* - - - - - - - - - - - - - - - - - - - - - - - */
/// <summary>
/// 將 Stream 寫入檔案
/// </summary>
public void StreamToFile(Stream stream,string fileName)
{
// 把 Stream 轉換成 byte[]
byte[] bytes = new byte[stream.Length];
stream.Read(bytes, 0, bytes.Length);
// 設定當前流的位置為流的開始
stream.Seek(0, SeekOrigin.Begin);

// 把 byte[] 寫入檔案
FileStream fs = new FileStream(fileName, FileMode.Create);
BinaryWriter bw = new BinaryWriter(fs);
bw.Write(bytes);
bw.Close();
fs.Close();
}

/// <summary>
/// 從檔案讀取 Stream
/// </summary>
public Stream FileToStream(string fileName)
{
// 開啟檔案
FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
// 讀取檔案的 byte[]
byte[] bytes = new byte[fileStream.Length];
fileStream.Read(bytes, 0, bytes.Length);
fileStream.Close();
// 把 byte[] 轉換成 Stream
Stream stream = new MemoryStream(bytes);
return stream;
}