可选参数，命名参数

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication3
{
    class Program
    {
        const bool testValue = true;
        static void Main(string[] args)
        {
            testDefault(true);
            testDefault(defaultValue3:4);
            testNormal(normalValue: false);
            Console.Read();
        }

        //static public void testDefault(bool defaultValue = testValue)
        //{
        //    Console.WriteLine("Default value: " + defaultValue.ToString());
        //}

        static public void testDefault(bool defaultValue1 = false, bool defaultValue2 = false, int defaultValue3 = 1)
        {
            Console.WriteLine("Default value1: " + defaultValue1.ToString());
            Console.WriteLine("Default value2: " + defaultValue2.ToString());
            Console.WriteLine("Default value3: " + defaultValue3.ToString());
        }

        static public void testNormal(bool normalValue)
        {
            Console.WriteLine("Normal value: " + normalValue.ToString());
        }

        //static public void testDefault(int defaultValue = 1)
        //{
        //    Console.WriteLine("Default value: " + defaultValue.ToString());
        //}
    }
}