C＃3.0（.NET 3.5）引入了對(duì)象初始化器語(yǔ)法，這是一種初始化類或集合對(duì)象的新方法。對(duì)象初始化程序允許您在創(chuàng)建對(duì)象時(shí)將值分配給字段或?qū)傩裕鵁o(wú)需調(diào)用構(gòu)造函數(shù)。
public class Student
{
public int StudentID { get; set; }
public string StudentName { get; set; }
public int Age { get; set; }
public string Address { get; set; }
}
class Program
{
static void Main(string[] args)
{
Student std = new Student() { StudentID = 1,
StudentName = "Bill",
Age = 20,
Address = "New York"
};
}
}在上面的示例中，沒(méi)有任何構(gòu)造函數(shù)的情況下定義了 Student 類。在 Main() 方法中，我們創(chuàng)建了Student對(duì)象，并同時(shí)為大括號(hào)中的所有或某些屬性分配了值。這稱為對(duì)象初始化器語(yǔ)法。
編譯器將上述初始化程序編譯為如下所示的內(nèi)容。
Student __student = new Student(); __student.StudentID = 1; __student.StudentName = "Bill"; __student.Age = 20; __student.StandardID = 10; __student.Address = "Test"; Student std = __student;
可以使用集合初始化器語(yǔ)法以與類對(duì)象相同的方式初始化集合。
var student1 = new Student() { StudentID = 1, StudentName = "John" };
var student2 = new Student() { StudentID = 2, StudentName = "Steve" };
var student3 = new Student() { StudentID = 3, StudentName = "Bill" } ;
var student4 = new Student() { StudentID = 3, StudentName = "Bill" };
var student5 = new Student() { StudentID = 5, StudentName = "Ron" };
IList<Student> studentList = new List<Student>() {
student1,
student2,
student3,
student4,
student5
};您還可以同時(shí)初始化集合和對(duì)象。
IList<Student> studentList = new List<Student>() {
new Student() { StudentID = 1, StudentName = "John"} ,
new Student() { StudentID = 2, StudentName = "Steve"} ,
new Student() { StudentID = 3, StudentName = "Bill"} ,
new Student() { StudentID = 3, StudentName = "Bill"} ,
new Student() { StudentID = 4, StudentName = "Ram" } ,
new Student() { StudentID = 5, StudentName = "Ron" }
};您還可以將null指定為元素：
IList<Student> studentList = new List<Student>() {
new Student() { StudentID = 1, StudentName = "John"} ,
null
};初始化程序語(yǔ)法使代碼更具可讀性，易于將元素添加到集合中。
在多線程中很有用。