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Inicializador de objeto de C#

C#3.0 (.NET 3.5)introdujoSintaxis del inicializador de objetos,Esta es una nueva forma de inicializar clases o objetos de conjuntos. El programa de inicialización de objetos permite asignar valores a campos o propiedades al crear el objeto, sin necesidad de llamar al constructor.

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,没有任何构造函数的情况下定义了 Student 类。在 Main() 方法中,我们创建了Student对象,并同时为大括号中的所有或某些属性分配了值。这称为对象初始化器语法。

编译器将上述初始化程序编译为如下所示的内容。

Student __student = new Student();
__student.StudentID = 1;
__student.StudentName = "Bill";
__student.Age = 20;
__student.StandardID = 10;
__student.Address = "Test";
Student std = __student;

集合初始化器语法

可以使用集合初始化器语法以与类对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 
                                                };

还可以同时初始化集合和对象。

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" } 
                };

También puede especificar null como elemento:

IList<Student> studentList = new List<Student>() { 
                                    new Student() { StudentID = 1, StudentName = "John"} ,
                                    null
                                };

Ventajas del inicializador

  • La sintaxis de inicializador hace que el código sea más legible y fácil de agregar elementos a la colección.

  • Muy útil en multihilo.