写出程序的输出结果 class Class1 { private string str = 'Class1.str' private int i = 0 static void StringConvert(string str) { str = 'string being converted.' } static void StringConvert(Class1 c) { c.str = 'string being converted.' } static void Add(int i) { i++ } static void AddWithRef(ref int i) { i++ } static void Main() { int i1 = 10 int i2 = 20 string str = 'str' Class1 c = new Class1() Add(i1) AddWithRef(ref i2) Add(c.i) StringConvert(str) StringConvert(c) Console.WriteLine(i1) Console.WriteLine(i2) Console.WriteLine(c.i) Console.WriteLine(str) Console.WriteLine(c.str) } }