C#实现UTC时间与Datetime转换

为了便于传输，通信过程中传输的都是：当前时间跟标准时间相隔的秒数，并且是以16进制字节的形式传输的。

public double ConvertDateTimeInt(System.DateTime time)//将时间格式的数据类型转换成浮点数类型   
        {
            double intResult = 0;
            System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1));
            intResult =(time - startTime).TotalSeconds;
            return intResult;
        }

        public DateTime ConvertIntDatetime(double utc)
        {
            System.DateTime startTime = TimeZone.CurrentTimeZone.ToLocalTime(new System.DateTime(1970, 1, 1));
            startTime = startTime.AddSeconds(utc);
            startTime = startTime.AddHours(8);//转化为北京时间(北京时间=UTC时间+8小时 )
            return startTime;
        }

 public byte[] ConvertDoubleByte(double d) 
        {
            byte[] result = new byte[4];
            float f=(float)d;
            result = BitConverter.GetBytes(f);
            return result;
        }

        public double  ConvertByteDouble(byte [] d)
        {
            double result=0;
            float q = BitConverter.ToSingle(d, 0);
            result = (double)q;
            return result;
        }

private void button1_Click(object sender, EventArgs e)//这种只是显示的形式不同，未达到目的
         {
             DateTime utc_tem = DateTime.UtcNow;

             double utc = ConvertDateTimeInt(utc_tem);//相对应的秒数！
             byte[] s = new byte[4];
            s = ConvertDoubleByte(utc);


            DateTime mytime = ConvertIntDatetime(1429647491.3936753);
            byte[] b = new byte[4] { 0x80,0x6d,0xaa,0x4e};
            mytime = ConvertIntDatetime(ConvertByteDouble(b));
        }