C#中byte与short、int、long互相转化

这个是转载别人的博客，转载地址：
http://www.cnblogs.com/pegasus923/archive/2010/10/08/1845866.html

public final static byte[] getBytes(short s, boolean asc) 
{
    byte[] buf = new byte[2];
    if (asc)
        for (int i = buf.length - 1; i >= 0; i--) 
        {
            buf[i] = (byte) (s & 0x00ff);
          s >>= 8;
        }
    else
        for (int i = 0; i < buf.length; i++) 
        {
            buf[i] = (byte) (s & 0x00ff);
          s >>= 8;
        }
    return buf;
}

public final static byte[] getBytes(int s, boolean asc) 
{
    byte[] buf = new byte[4];
    if (asc)
      for (int i = buf.length - 1; i >= 0; i--) 
      {
        buf[i] = (byte) (s & 0x000000ff);
        s >>= 8;
      }
    else
      for (int i = 0; i < buf.length; i++)
      {
        buf[i] = (byte) (s & 0x000000ff);
        s >>= 8;
      }
    return buf;
}

public final static byte[] getBytes(long s, boolean asc) 
{
    byte[] buf = new byte[8];
    if (asc)
      for (int i = buf.length - 1; i >= 0; i--) 
        {
        buf[i] = (byte) (s & 0x00000000000000ff);
        s >>= 8;
      }
    else
      for (int i = 0; i < buf.length; i++) 
        {
        buf[i] = (byte) (s & 0x00000000000000ff);
        s >>= 8;
      }
    return buf;
}

public final static short getShort(byte[] buf, boolean asc) 
{
    if (buf == null) 
    {
      throw new IllegalArgumentException("byte array is null!");
    }
    if (buf.length > 2) 
    {
      throw new IllegalArgumentException("byte array size > 2 !");
    }
    short r = 0;
    if (asc)
      for (int i = buf.length - 1; i >= 0; i--) 
        {
        r <<= 8;
        r |= (buf[i] & 0x00ff);
      }
    else
      for (int i = 0; i < buf.length; i++) 
        {
        r <<= 8;
        r |= (buf[i] & 0x00ff);
      }
    return r;
}

public final static int getInt(byte[] buf, boolean asc) 
{
    if (buf == null) 
    {
      throw new IllegalArgumentException("byte array is null!");
    }
    if (buf.length > 4) 
    {
      throw new IllegalArgumentException("byte array size > 4 !");
    }
    int r = 0;
    if (asc)
      for (int i = buf.length - 1; i >= 0; i--) 
        {
        r <<= 8;
        r |= (buf[i] & 0x000000ff);
      }
    else
      for (int i = 0; i < buf.length; i++) 
        {
        r <<= 8;
        r |= (buf[i] & 0x000000ff);
      }
    return r;
}

public final static long getLong(byte[] buf, boolean asc) 
{
    if (buf == null) 
    {
      throw new IllegalArgumentException("byte array is null!");
    }
    if (buf.length > 8) 
    {
      throw new IllegalArgumentException("byte array size > 8 !");
    }
    long r = 0;
    if (asc)
      for (int i = buf.length - 1; i >= 0; i--) 
        {
        r <<= 8;
        r |= (buf[i] & 0x00000000000000ff);
      }
    else
      for (int i = 0; i < buf.length; i++) 
        {
        r <<= 8;
        r |= (buf[i] & 0x00000000000000ff);
      }
    return r;
}