Question

How can I format a number to a fixed number of decimal places (keep trailing zeroes) where the number of places is specified by a variable?

e.g.

int x = 3; Console.WriteLine(Math.Round(1.2345M, x)); // 1.234 (good) Console.WriteLine(Math.Round(1M, x));      // 1   (would like 1.000) Console.WriteLine(Math.Round(1.2M, x));    // 1.2 (would like 1.200) 

Note that since I want to control the number of places programatically, this string.Format won’t work (surely I ought not generate the format string):

Console.WriteLine(     string.Format('{0:0.000}', 1.2M));    // 1.200 (good) 

Should I just include Microsoft.VisualBasic and use FormatNumber?

I’m hopefully missing something obvious here.

Answer 1

Try

decimal x = 32.0040M; string value = x.ToString('N' + 3 /* decimal places */); // 32.004 string value = x.ToString('N' + 2 /* decimal places */); // 32.00 // etc. 

Hope this works for you. See

http://msdn.microsoft.com/en-us/library/dwhawy9k.aspx

for more information. If you find the appending a little hacky try:

public static string ToRoundedString(this decimal d, int decimalPlaces) {     return d.ToString('N' + decimalPlaces); } 

Then you can just call

decimal x = 32.0123M; string value = x.ToRoundedString(3);  // 32.012;