C# 获取当前总毫秒数的实例讲解

//获取当前Ticks
long currentTicks= DateTime .Now.Ticks;
DateTime dtFrom = new DateTime (1970, 1, 1, 0, 0, 0, 0);
long currentMillis = (currentTicks - dtFrom.Ticks) / 10000;

DateTime now = DateTime.Now;
byte[] bts = BitConverter.GetBytes(now.ToBinary());
DateTime rt = DateTime.FromBinary(BitConverter.ToInt64(bts, 0)); 

 // Date -> byte[2] 
 public static byte[] DateToByte(DateTime date) 
 { 
  int year = date.Year - 2000; 
  if (year < 0 || year > 127) 
  return new byte[4]; 
  int month = date.Month; 
  int day = date.Day; 
  int date10 = year * 512 + month * 32 + day; 
  return BitConverter.GetBytes((ushort)date10); 
 } 
 // byte[2] -> Date 
 public static DateTime ByteToDate(byte[] b) 
 { 
  int date10 = (int)BitConverter.ToUInt16(b, 0); 
  int year = date10 / 512 + 2000; 
  int month = date10 % 512 / 32; 
  int day = date10 % 512 % 32; 
  return new DateTime(year, month, day); 
 } 

byte[] write = DateToByte(DateTime.Now.Date); 
MessageBox.Show(ByteToDate(write).ToString("yyyy-MM-dd"));

/// <summary> 2. /// 将BYTE数组转换为DATETIME类型 3. /// </summary> 4. /// <param name="bytes"></param> 5. /// <returns></returns> 6. private DateTime BytesToDateTime(byte[] bytes)
 {
  if (bytes != null && bytes.Length >= 5)
  {
  int year = 2000 + Convert.ToInt32(BitConverter.ToString(new byte[1] { bytes[0] }, 0));
  int month = Convert.ToInt32(BitConverter.ToString(new byte[1] { bytes[1] }, 0));
  int date = Convert.ToInt32(BitConverter.ToString(new byte[1] { bytes[2] }, 0));
  int hour = Convert.ToInt32(BitConverter.ToString(new byte[1] { bytes[3] }, 0));
  int minute = Convert.ToInt32(BitConverter.ToString(new byte[1] { bytes[4] }, 0));
  DateTime dt = new DateTime(year, month, date, hour, minute, 0);
  return dt;
  }
  else19.  {
  return new DateTime();
  }
 }