如何始终在逗号后显示三位数字

Question

Lets say i have a TextBox. When i write 0.5 i want it to Show it as 0.500 automatically.

My Problem is that as soon as the Digits after the comma are 0 they get cut off.

Example

0.5 -> 0.500

0.51 -> 0.510

The Change itself will happen in the LostFocus Event (Excel like calculation).

I Need fixed 3 Digits.

Answer 1

In short:

 var output = string.Format("{0:#,0.000}", value));   

Ex:

 float[] values = new float[] { 0.5f, 0.51f, 0.51234f };
 foreach( var v in values)
      Console.WriteLine(string.Format("{0:#,0.000}", v));            
 Console.ReadKey();

Answer 2

if you are in WPF, you can do it in XAML:

<TextBlock Text="{Binding Path=Length, StringFormat={}{0:#000}}" TextAlignment="Right"/>