详解C#中使用对象或集合的初始值设定项初始化的操作

public class Program{  public static void Main()  {    // Declare a StudentName by using the constructor that has two parameters.    StudentName student1 = new StudentName("Craig", "Playstead");    // Make the same declaration by using an object initializer and sending     // arguments for the first and last names. The default constructor is     // invoked in processing this declaration, not the constructor that has    // two parameters.    StudentName student2 = new StudentName    {      FirstName = "Craig",      LastName = "Playstead",    };    // Declare a StudentName by using an object initializer and sending     // an argument for only the ID property. No corresponding constructor is    // necessary. Only the default constructor is used to process object     // initializers.    StudentName student3 = new StudentName    {      ID = 183    };    // Declare a StudentName by using an object initializer and sending    // arguments for all three properties. No corresponding constructor is     // defined in the class.    StudentName student4 = new StudentName    {      FirstName = "Craig",      LastName = "Playstead",      ID = 116    };    System.Console.WriteLine(student1.ToString());    System.Console.WriteLine(student2.ToString());    System.Console.WriteLine(student3.ToString());    System.Console.WriteLine(student4.ToString());  }}

Craig 0Craig 0183Craig 116

public class StudentName{  // The default constructor has no parameters. The default constructor   // is invoked in the processing of object initializers.   // You can test this by changing the access modifier from public to   // private. The declarations in Main that use object initializers will   // fail.  public StudentName() { }  // The following constructor has parameters for two of the three   // properties.   public StudentName(string first, string last)  {    FirstName = first;    LastName = last;  }  // Properties.  public string FirstName { get; set; }  public string LastName { get; set; }  public int ID { get; set; }  public override string ToString()  {    return FirstName + " " + ID;  }}

List<StudentName> students = new List<StudentName>(){ new StudentName {FirstName="Craig", LastName="Playstead", ID=116}, new StudentName {FirstName="Shu", LastName="Ito", ID=112}, new StudentName {FirstName="Gretchen", LastName="Rivas", ID=113}, new StudentName {FirstName="Rajesh", LastName="Rotti", ID=114}};

class StudentName{  public string FirstName { get; set; }  public string LastName { get; set; }  public int ID { get; set; }}class CollInit{  Dictionary<int, StudentName> students = new Dictionary<int, StudentName>()  {    { 111, new StudentName {FirstName="Sachin", LastName="Karnik", ID=211}},    { 112, new StudentName {FirstName="Dina", LastName="Salimzianova", ID=317}},    { 113, new StudentName {FirstName="Andy", LastName="Ruth", ID=198}}  };}