将指数转换为字符串

Question

I am using the below code to convert exponential number to string. It's working partially. Please help me to do this.

This is my Exponential number is 4.00658E+16 //In text format '40065812120130567'

The below code convert this number to 40065812120130600. Some times it didn't convert the last two digits. Please help me to solve this issue.

 decimal device;
 string dvc_id = Convert.ToString(dt.Rows[i][4]);//dt.Rows[i][4]

 decimal.TryParse(dvc_id, NumberStyles.Any, CultureInfo.InvariantCulture, out device);
 dvc_id = device.ToString();

Answer 1

The number 4.00658121201306E+16 , which you say you are using, is NOT the same as 40065812120130567 . The last two digits are dropped because the exponential form does not have those digits as part of the number.

The last two digits aren't stored at all in that number. All exponential notation does is tell where the decimal point should be, essentially. What you see is what you get in terms of the precision of the value, and you're not giving the program any digits after the six. Hence, it won't give you any digits after the six.

Answer 2

你可以尝试下面的代码吗

var num = Decimal.Parse("4.00658E+16", System.Globalization.NumberStyles.Float);

Answer 3

建议使用BigInteger类：

var number = BigInteger.Parse("400658121201306000000000000");