C#6 的一些新语法

    public class People     {         public int Id { get; set; }         public string Name { get; set; }         public int Age { get; set; }         /// <summary>         ///C#6新语法. :8.自动实现的属性初始化器         /// </summary>         public DateTime BirthDay { get; set; } = DateTime.Now.AddYears(-22);          /// <summary>         /// C#6新语法:在属性/方法里使用Lambda表达式(Expression bodies on property-like function members)         /// </summary>         public string NameFormat => string.Format("姓名：{0}", "NameFormat");         /// <summary>         /// C#6新语法:在属性/方法里使用Lambda表达式(Expression bodies on property-like function members)         /// </summary>         public void Print() => WriteLine(NameFormat);     }

            {                 Console.WriteLine("Hello!");

                Console.WriteLine($"之前的使用方式[静态类.]：{Math.Max(2, 3)}"); 
            }

            //引入命名空间             using static System.Math;             using static System.Console;

            WriteLine("Hello!");             WriteLine($"现在的使用方式引入命名空间，这边直接调用：{ Max(2, 3)}");

            #region 2.字符串嵌入值(String interpolation)             {                 WriteLine($"Id：{people.Id}  姓名：{people.Name} 生日：{people.BirthDay.ToString("yyyy-MM-dd")}");                                  WriteLine($"{(people.Age >= 25 ? "腊肉" : "鲜肉")}");                  WriteLine($"Id：{{{people.Id}}} 姓名：{{{people.Name}}}");             }             #endregion

            #region 3.空值运算符(Null-conditional operators) 可空判断             {                 int? iValue = null;                 string sValue = iValue?.ToString();//string sValue = iValue.ToString();不判断会报错                 iValue = Convert.ToInt32(sValue);                 WriteLine($"iValue：{iValue}");                 string sName = "";                 WriteLine($"sName：{sName?.ToString()}");             }             #endregion

            #region 4.对象初始化器(Index Initializers)             {                 //之前通过add方法，add keyvalue进去                 {                     IDictionary<int, string> dictOld = new Dictionary<int, string>() { };                     dictOld.Add(1, "M");                     dictOld.Add(2, "A");                     dictOld.Add(3, "X");                     foreach (var keyValue in dictOld)                     {                         Console.WriteLine($"key:{keyValue.Key},value:{keyValue.Value}");                     }                 }                  {                     IDictionary<int, string> dictOld1 = new Dictionary<int, string>()                     {                         { 1,"M"},{ 2,"A"},{ 3,"X"}                     };                 }                  {                     //通过索引的方式给字段进行初始化                     IDictionary<int, DateTime> dictNew = new Dictionary<int, DateTime>()                     {                         [1] = DateTime.Now,                         [2] = DateTime.Now.AddDays(-1),                         [3] = DateTime.Now.AddDays(-2)                     };                     foreach (var keyValue in dictNew)                     {                         Console.WriteLine($"key:{keyValue.Key},value:{keyValue.Value}");                     }                 }             }             #endregion

            #region 5.异常过滤器(Exception filters)             {                 int iExceptionValue = 2;                 try                 {                     Int32.Parse("S");//Parse类型强制转换                 }                 catch (Exception e) when (iExceptionValue > 1)                 {                     WriteLine(e.Message);                 }             }             #endregion

            #region 6.nameof表达式 (nameof expressions)             {                 /*比如我们平时喜欢写字符串的形式，如果项目越来越大，后期突然哪个不用了，              * 使用字符串的形式维护起来就会很麻烦，用nameof就可以很好的解决，最重要的是不会影响性能！*/                 WriteLine(nameof(people));                 WriteLine(nameof(people.Name));             }             #endregion

        /// <summary>         /// C#6新语法:在属性/方法里使用Lambda表达式(Expression bodies on property-like function members)         /// </summary>         public string NameFormat => string.Format("姓名：{0}", "NameFormat");         /// <summary>         /// C#6新语法:在属性/方法里使用Lambda表达式(Expression bodies on property-like function members)         /// </summary>         public void Print() => WriteLine(NameFormat);

            #region 7.在属性/方法里使用Lambda表达式(Expression bodies on property-like function members)             {                 people.Print();             }             #endregion