C# OUT 传参问题

错误 CS0177  控制离开当前方法之前必须对OUT参数赋值 
我明明赋值了  为何出错? (本人新学C#等待高手指教)public class ooo
    {
        public static void yubao(string xuanze, out string sun, out double max, out double min, out string wind, out string play)
        {
            #region            switch (xuanze)
            {
                case "1":                    sun = "晴";
                    max = 10.5;
                    min = 25.6;
                    wind = "5 6 级";
                    play = "适合外出游玩";                    break;
                case "2":                    sun = "阴";
                    max = 8.5;
                    min = 20.6;
                    wind = "3 4 级";
                    play = "不适合外出游玩";
                    break;
                case "3":                    sun = "多云";
                    max = 35.6;
                    min = 22.3;
                    wind = "1 2 级";
                    play = "......";
                    break;
                case "4":                    sun = "晴转多云";
                    max = 33.5;
                    min = 21.5;
                    wind = "2 3 级";
                    play = "......";
                    break;
                default:
                    Console.WriteLine("1------4");
                    break;
            }            #endregion        }
    }