Format a number to always have a sign and decimal separator [duplicate]

问题

This question already has answers here:

Custom numeric format string to always display the sign (6 answers)

Closed 5 years ago.

I want to format any number (integer or real) to a string representation which always has a sign (positive or negative) and a decimal separator, but no trailing zeroes.

Some samples:

3.14 => +3.14
12.00 => +12.
-78.4 => -78.4
-3.00 => -3.

Is it possible with one of the default ToString() implementations, or do I need write this myself?

回答1:

Try something like this:

double x = -12.43;
string xStr = x.ToString("+0.#####;-0.#####");

But this wouldn't help to display trailing decimal point. You can handle such situations using this method:

public static string MyToString(double x)
{
    return x == Math.Floor(x)
        ? x.ToString("+0;-0;0") + CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator
        : x.ToString("+0.####;-0.####");
}

回答2:

You can try like this:

string myFormatedString = number.ToString("+#;-#");

回答3:

The format string you want to use is

ToString("N", CultureInfo.InvariantCulture) // Displays -12,445.68

See here for additional options for format strings

来源：https://stackoverflow.com/questions/25725378/format-a-number-to-always-have-a-sign-and-decimal-separator