MemoryStream ms = new MemoryStream(bytes);

ms.Position = ;

Image img = Image.FromStream(ms);

ms.Close();

System.Text.UnicodeEncoding converter = new System.Text.UnicodeEncoding();

byte[] inputBytes =converter.GetBytes(inputString);

string inputString = converter.GetString(inputBytes);

string inputString = System.Convert.ToBase64String(inputBytes);

byte[] inputBytes = System.Convert.FromBase64String(inputString);

FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);

/// 将 Stream 转成 byte[]

public byte[] StreamToBytes(Stream stream)

{

    byte[] bytes = new byte[stream.Length];

    stream.Read(bytes, , bytes.Length);

    // 设置当前流的位置为流的开始

    stream.Seek(, SeekOrigin.Begin);

    return bytes;

}

/// 将 byte[] 转成 Stream

public Stream BytesToStream(byte[] bytes)

{

    Stream stream = new MemoryStream(bytes);

    return stream;

}

// 将Stream读取到文件

public void StreamToFile(Stream stream,string fileName)

{

    // 把 Stream 转换成 byte[]

    byte[] bytes = new byte[stream.Length];

    stream.Read(bytes, , bytes.Length);

    // 设置当前流的位置为流的开始

    stream.Seek(, 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();

}

// 从文件读取Stream

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 = new byte[fileStream.Length];

    fileStream.Read(bytes, , bytes.Length);

    fileStream.Close();

    // 把 byte[] 转换成 Stream

    Stream stream = new MemoryStream(bytes);

    return stream;

}

//Bitmap 转化为 Byte[]

Bitmap BitReturn = new Bitmap();

byte[] bReturn = null;

MemoryStream ms = new MemoryStream();

BitReturn.Save(ms, System.Drawing.Imaging.ImageFormat.Png);

bReturn = ms.GetBuffer();