Binary in .Net

Use the "Convert" class.

string binStr = "1100110001";
long number = Convert.ToInt64(binStr, 2);

Console.WriteLine(binStr + " in binary : " + number + " in decimal");

also from C# version 7 it is possible to declare numeric values in terms of binary literals:

int binaryLiteral = 0b0010_0110_0000_0011;
int binaryLiteral2 = 0b0010011000000011;
Debug.Assert(binaryLiteral == binaryLiteral2);

Console.WriteLine("0b0010_0110_0000_0011 in binary : " + binaryLiteral + " in decimal");

Finally to convert a number to a binary string

int number = 9731;
string binary = Convert.ToString(number, 2);

Console.WriteLine(number + " in binary : " + binary);