ref、out 关键字

    class ParameterTest
    {
        static void Main(string[] args)
        {
            int i = 0;
            int[] ints = { 0, 1, 2, 4, 8 };

            Console.WriteLine("i = " + i);
            Console.WriteLine("ints[0] = " + ints[0]);

            SomeFunction(ints,i);
            Console.WriteLine("i = " + i);
            Console.WriteLine("ints[0] = " + ints[0]);

            Console.ReadKey();
        }

        static void SomeFunction(int[] ints,int i)
        {
            ints[0] = 100;
            i = 100;
        }
    }

    class ParameterTest
    {
        static void Main(string[] args)
        {
            int i = 0;
            int[] ints = { 0, 1, 2, 4, 8 };

            Console.WriteLine("i = " + i);
            Console.WriteLine("ints[0] = " + ints[0]);

            SomeFunction(ints,ref i);
            Console.WriteLine("i = " + i);
            Console.WriteLine("ints[0] = " + ints[0]);

            Console.ReadKey();
        }

        static void SomeFunction(int[] ints,ref int i)
        {
            ints[0] = 100;
            i = 100;
        }
    }

如果把一个参数传递给方法，且这个方法的输入参数钱带有ref关键字，则改方法对变量所做的任何改变都会影响原始对象的值。

    class OutTest
    {
        static void Main(string[] args)
        {
            int i;
            SomeFunction(out i);
            Console.WriteLine(i);

            Console.ReadKey();
        }

        static void SomeFunction(out int i)
        {
            i = 100;
        }
    }

变量如果未赋初始值而是用肯定会报错，而是用Out关键字之后可以解决这一问题