[c#] int to hex string

I need to convert an int to hex string.

When converting 1400 => 578 using ToString("X") or ToString("X2") but I need it like 0578.

Can anyone provide me the IFormatter to ensure that the string is 4 chars long?

Try C# string interpolation introduced in C# 6:

var id = 100;
var hexid = $"0x{id:X}";

hexid value:

"0x64"

Previous answer is not good for negative numbers. Use a short type instead of int

        short iValue = -1400;
        string sResult = iValue.ToString("X2");
        Console.WriteLine("Value={0} Result={1}", iValue, sResult);

Now result is FA88

Try the following:

ToString("X4")

See The X format specifier on MSDN.