自动属性，对象初始化器，集合初始化器和lambda表达式

C#在2.0以后进入了一些新特性，如 自动属性，对象初始化器，集合初始化器和lambda表达式，另外还包括匿名方法、可空类型和扩展方法等。
详细见我2007年的文章，现测试几个初始化器在语法层面和reflector以后对比，可发现哪些是语法甜点，那些是CLR内置的改进。

1.自动属性：AutoProperty
           直接给出类内属性field的名称，后面跟{}，并在内部简单写get; set;即可。 编译器将自动创建私有属性字段，并实现get_属性名称和 set_属性名称method，属于编译器语法甜头。

public string FirstName{get;set;}

2.对象初始化器：Object Initilizer
            简单讲就是可以在对象初始化的时候直接完成其属性的赋值。语法是在new 对象后紧跟{}，并在{}内部设置属性的名称并赋值。
new Student{FirstName="Sophie", LastName="UX",Corperation="ibm"}
3.集合初始化器：Collection Initilizer
           语法上在集合类型实例化语句New后面紧跟{}，并在{}内填写元素.

double[] score = {98.5, 93.5, 99, 65.5}; float[] mesure = new float[]{98.5f, 93.5f, 99f, 65.5f};

4.lambda表达式: lambda expression

详细见下面的代码吧

//csc Initializer.cs /r:System.Linq.dll
using System;
using System.Linq;
using System.Collections.Generic;

public class Student
{//auto property
    public string FirstName{get;set;}
    public string LastName{get;set;}
    public string Corperation{get;set;}
}


public class MyClass
{
    public static void Main()
    {    //List    Generic
        List<Student> students = new List<Student>{//Collection Initializer
            new Student{FirstName="xu", LastName="Minghui", Corperation="LYPOWER"},
            new Student{FirstName="Sophie", LastName="UX",Corperation="ibm"},
            new Student{FirstName="xu", LastName="zisheng", Corperation="Home"}
            //Object Initializer: give property value directly in a {} scope
        };
        
        var result1 = students.Where( p => p.FirstName.StartsWith("xu") );
        var result2 = from  stu in students where stu.FirstName.StartsWith("xu") select stu;
        foreach(var v in result1)
            Console.WriteLine("{0} {1} work at {2}.", v.FirstName, v.LastName, v.Corperation);
        foreach(var v in result2)
            Console.WriteLine("{0} {1} work at {2}.", v.FirstName, v.LastName, v.Corperation);
        Console.ReadKey();
    }
}
/*
public static void Main()
{
    List<Student> list2 = new List<Student>();
    Student item = new Student {
        FirstName = "xu",
        LastName = "Minghui",
        Corperation = "LYPOWER"
    };
    list2.Add(item);
    Student student3 = new Student {
        FirstName = "Sophie",
        LastName = "UX",
        Corperation = "ibm"
    };
    list2.Add(student3);
    Student student4 = new Student {
        FirstName = "xu",
        LastName = "zisheng",
        Corperation = "Home"
    };
    list2.Add(student4);
    List<Student> list = list2;
    IEnumerable<Student> enumerable = from p in list
        where p.FirstName.StartsWith("xu")
        select p;
    IEnumerable<Student> enumerable2 = from stu in list
        where stu.FirstName.StartsWith("xu")
        select stu;
    foreach (Student student in enumerable)
    {
        Console.WriteLine("{0} {1} work at {2}.", student.FirstName, student.LastName, student.Corperation);
    }
    foreach (Student student in enumerable2)
    {
        Console.WriteLine("{0} {1} work at {2}.", student.FirstName, student.LastName, student.Corperation);
    }
    Console.ReadKey();
}
*/