之前属性为如下所示，属性赋值需在构造函数对其初始化
1 public int Id { get; set; }
2 public string Name { get; set; }
更新后
public string Name { get; set; } = "summit";
public int Age { get; set; } = 22;
public DateTime BirthDay { get; set; } = DateTime.Now.AddYears(-20);
public IList<int> AgeList
{
get;
set;
} = new List<int> { 10, 20, 30, 40, 50 };
2、直接引用静态类
如果之前调用静态类中的方法，如下书写：
Math.Abs(20d);
更新后：
using static System.Math;
private void Form1_Load(object sender, EventArgs e)
{
Abs(20d);
}
3、Null 条件运算符
之前在使用对象时，需要先进性判断是否为null
if (student!=null)
{
string fullName = student.FullName;
}
else
{
//……
}
更新后：
string fullName = student?.FullName; //如果student为空则返回Null,不为空则返回.FullNaem,注意！得到的结果一定是要支持null
4、字符串内插
string str = $"{firstName}和{lastName}"
5、异常筛选器
try
{
}
catch(Exception e) when(e.Message.Contains("异常过滤，把符合条件的异常捕获")
{
}
6、nameof 表达式可生成变量、类型或成员的名称作为字符串常量
Console.WriteLine(nameof(System.Collections.Generic)); // output: Generic Console.WriteLine(nameof(List<int>)); // output: List
7、使用索引器初始化对字典进行赋值
Dictionary<int, string> messages = new Dictionary<int, string>
{
{ 404, "Page not Found"},
{ 302, "Page moved, but left a forwarding address."},
{ 500, "The web server can't come out to play today."}
};
同时也可以这样通过索引的方式进行赋值
Dictionary<int, string> webErrors = new Dictionary<int, string>
{
[404] = "Page not Found",
[302] = "Page moved, but left a forwarding address.",
[500] = "The web server can't come out to play today."
};
8、在属性/方法里面使用Lambda表达式
public string NameFormat => string.Format("姓名: {0}", "summit");
public void Print() => Console.WriteLine(Name);