建造者模式和工廠模式的區別

它們目的都是創建一個復雜的對象

工廠模式注重的是整體對象的創建方法，而建造者模式注重的是對象的創建過程，創建對象的過程方法可以在創建時自由調用。

 

看一下建造者模式的例子就明白了：

public class EmployeeBuilder
{
    private int id = 1;
    private string firstname = "first";
    private string lastname = "last";
    private DateTime birthdate = DateTime.Today;
    private string street = "street";

    public Employee Build()
    {
        return new Employee(id, firstname, lastname, birthdate, street);
    }

    public EmployeeBuilder WithFirstName(string firstname)
    {
        this.firstname = firstname;
        return this;
    }

    public EmployeeBuilder WithLastName(string lastname)
    {
        this.lastname = lastname;
        return this;
    }

    public EmployeeBuilder WithBirthDate(DateTime birthdate)
    {
        this.birthdate = birthdate;
        return this;
    }

    public EmployeeBuilder WithStreet(string street)
    {
        this.street = street;
        return this;
    }

    public static implicit operator Employee(EmployeeBuilder instance)
    {
        return instance.Build();
    }
}

調用：

void main(){
Employee emp1 = new EmployeeBuilder().WithFirstName("Kenneth")
                                            .WithLastName("Truyers");

Employee emp2 = new EmployeeBuilder().WithBirthDate(new DateTime(1983, 1,1));
}