using System;
using System.Globalization;
public class Example
{
public static void Main()
{
double doubleNumber;
doubleNumber = 123456.1234;
Console.WriteLine(doubleNumber.ToString("F", CultureInfo.InvariantCulture));
Console.WriteLine(doubleNumber.ToString("F0", CultureInfo.InvariantCulture));
doubleNumber = -12345678.1234;
Console.WriteLine(doubleNumber.ToString("F1", CultureInfo.InvariantCulture));
Console.WriteLine(doubleNumber.ToString("F3", CultureInfo.CreateSpecificCulture("es-ES")));
}
}
/*
123456.12
123456
-12345678.1
-12345678,123
*/