شما باید از F فرمت استفاده کنید:
این هم لینکش
http://msdn.microsoft.com/en-us/libr...v=vs.110).aspx
int integerNumber;
integerNumber = 17843;
Console.WriteLine(integerNumber.ToString("F",
CultureInfo.InvariantCulture));
// Displays 17843.00
integerNumber = -29541;
Console.WriteLine(integerNumber.ToString("F3",
CultureInfo.InvariantCulture));
// Displays -29541.000
double doubleNumber;
doubleNumber = 18934.1879;
Console.WriteLine(doubleNumber.ToString("F", CultureInfo.InvariantCulture));
// Displays 18934.19
Console.WriteLine(doubleNumber.ToString("F0", CultureInfo.InvariantCulture));
// Displays 18934
doubleNumber = -1898300.1987;
Console.WriteLine(doubleNumber.ToString("F1", CultureInfo.InvariantCulture));
// Displays -1898300.2
Console.WriteLine(doubleNumber.ToString("F3",
CultureInfo.CreateSpecificCulture("es-ES")));
// Displays -1898300,199