public void TypeConvert()

        {

            int a = 12;

            double b = 35.5;

            Console.WriteLine((int)b);//显示类型转换

            //使用convert、parse强制类型转换

            String s = "123";

            int i = int.Parse(s);

            int j = Convert.ToInt32(s);

            Console.WriteLine("{0} {1}",i,j);

            //该方式也是将数字内容的字符串转换为int类型，但是该方式比int.Parse(string s) 好一些，它不会出现异常。最后一个参数result是输出值，如果转换成功则输出相应的值，转换失败则输出0。

            string s1 = "abcd";

            string s2 = "1234";

            int c, d;

            bool bo1 = int.TryParse(s1, out c);

            Console.WriteLine(s1 + " " + bo1 + " " + c);

            bool bo2 = int.TryParse(s2, out d);

            Console.WriteLine(s2 + " " + bo2 + " " + d);

            String str = "abc";

            char ch = 'a';

            Console.WriteLine(str.ToUpper());

            Console.WriteLine(b.ToString());

            Console.WriteLine(ch.CompareTo('d'));

        }