C# String.Format for Double/Decimal Values

The following examples show how to format float numbers to string in C#. You can use static method String.Format or instance methods double.ToString and float.ToString.
Digits after decimal point

This example formats double to string with fixed number of decimal places. For two decimal places use pattern "0.00". If a float number has less decimal places, the rest digits on the right will be zeroes. If it has more decimal places, the number will be rounded.
[C#]

// just two decimal places
String.Format("{0:0.00}", 123.4567);      // "123.46"
String.Format("{0:0.00}", 123.4);         // "123.40"
String.Format("{0:0.00}", 123.0);         // "123.00

More examples are in the original article here...