//tempNum为10进制电压值
//转换规则：字符串转为2位16进制字符串，不够就补位
string x = this.DtoX(int.Parse(voltageValue)).PadLeft(4, '0');
//高位在前，低位在后
string maxVoltageHex = x.Substring(2, 2)  + x.Substring(0, 2);

//十进制转十六进制
public string DtoX(int d)
        {
            string x = "";
            if (d < 16)
            {
                x = Chang(d);
            }
            else
            {
                int c;

                int s = 0;
                int n = d;
                int temp = d;
                while (n >= 16)
                {
                    s++;
                    n = n / 16;
                }
                string[] m = new string[s];
                int i = 0;
                do
                {
                    c = d / 16;
                    m[i++] = Chang(d % 16); //判断是否大于10，如果大于10，则转换为A~F的格式
                    d = c;
                } while (c >= 16);
                x = Chang(d);
                for (int j = m.Length - 1; j >= 0; j--)
                {
                    x += m[j];
                }
            }
            return x;
        }