swift中byte和Data之间的转换

byte和Data之间的转换

   var b:[Byte] = [13,0xf1,0x20]
   var d = NSData(bytes: b, length: 3)

   //把NSData的值存到byteArray中
   var byteArray:[Byte] = [Byte]()
   for i in 0..<3 {
         var temp:Byte = 0
         d.getBytes(&temp, range: NSRange(location: i,length:1 ))
         byteArray.append(temp)
    }

四个字节的byte转整形数据

  /** 4个字节Bytes 转 int*/
  unsigned int bytesValueToInt(Byte *bytesValue) {
  unsigned int  intV;
  intV = (unsigned int ) ( ((bytesValue[3] & 0xff)<<24)
                        |((bytesValue[2] & 0xff)<<16)
                        |((bytesValue[1] & 0xff)<<8)
                        |(bytesValue[0] & 0xff));
  return intV; 
 }