refer : 

http://www.cnblogs.com/yinrq/p/5600530.html

http://www.cnblogs.com/wolf-sun/p/5168217.html

http://www.cnblogs.com/wolf-sun/p/5172914.html

 

使用 vs2015 .net 4.6.1

 

1. nameof

public class Demo{    public string name { get; set; }}string value = nameof(Demo.name); //"name"

好处 : 类似 enum 的作用, 当要批量替换属性名字时, 有智能提示, 这样就不怕漏换了.

 

2.null 处理

public class Demo{    public string name { get; set; } 　　 public int age { get; set; }    public void doSomeThing()    {    }}Demo demo = null;//before       if (demo != null) demo.doSomeThing();           //afterdemo?.doSomeThing();                                         //before                       string valuex = (demo != null) ? demo.name : "defaultValue";//afterstring valuey = demo?.name ?? "defaultValue"; // for int int? age = demo?.age; int age = (demo?age).GetValueOrDefault();

是 null 的话后面就不会继续跑, 会直接返回 null 值,

如果是 int 也会变成 nullable 哦，看上面的例子. 

 

3. using static 

namespace Project{    public class Demo    {        public static void method()        {        }    }}using static Project.Demo;//beforeDemo.method();//aftermethod();

好处 : 不需要写 ClassName 

 

4. string interpolation

string value1 = "kelly";string value2 = "penny";//beforestring value4 = string.Format("i love {0}, i have {1}", value1, value2); //afterstring value3 = $"i love {value1}, i hate {value2}"; //i love kelly, i hate penny

好处 : 早就好这样了, string.Format 和 "+ +" 一样乱丫, 不过还是 js 的 `` 更好 

 

5. lambda in class method and properties

public class Demo{     //before    public string getString1(string value)    {        return $"i love {value}";    }    //after    public string getString2(string value) => $"i love {value}";    //before    public string fullname1 {        get {            return getString1("kelly");        }    }    //after    public string fullname => getString1("kelly"); //this feature only support get }

好处 : 好看一些吧

 

6. default value in class properties

//beforepublic class Demo1{    public Demo1()    {        this.name = "value";    }    public string name { get; set; }}//afterpublic class Demo2{    public string name { get; set; } = "value";}

好处 : 美 

 

7. 字典

//beforeDictionary
     
       data1 = new Dictionary
      
       {    { "key1" , "value" },    { "key2" , "value" }};//afterDictionary
       
         data2 = new Dictionary
        
         {    ["key1"] = "value",    ["key2"] = "value",};
        
       
      
     

好处 : 比较贴近正常的赋值 data2["ket1"] = "value";