如何将类实例作为句柄在Matlab中传递

Question

一个假设的场景来问我的问题：

假设我们有两个实体:一个老板和一个雇员。当员工完成一项工作时，他/她想让人们知道。在这种情况下，老板会订阅消息并决定该做什么

我实现了这个接口，它具有任何其他类都可以实现的抽象方法。在这种情况下(因为他/她将决定他/她想做什么)：

classdef (Abstract) Interface < handle

    methods
        getJobsCompleted(n)
    end

end

boss类继承接口并实现方法getJobsCompleted()

classdef Boss < Interface & handle

    properties
        myEmployee
    end

    methods
        function this = Boss()
            this.myEmployee = Employee(this)

            this.myEmployee.doJobs();
        end
        %My boss implements (i.e. decides what to do) the abstract method
        function getJobsCompleted(n)

            %DO SOMETHING with n
        end
    end

end

最后，员工执行工作并通知老板。

classdef Employee < handle

    properties
        numJobsCompleted;
        boss = [];%pointer or reference to Boss instance
    end

    methods
        function this = Employee(myBoss)
            this.boss = myBoss; %reference/pointer to my boss so I know who to notify
        end

        function doJobs()
           %% do something then let boss know
           this.numJobsCompleted = 40;
           this.boss.getJobsCompleted(this.numJobsCompleted);
        end

    end

end

我一直试图做的是传递一个对雇员类的引用，以便他/她知道该通知哪个老板。

即

in Boss
this.myEmployee = Employee(this)

Answer 1

这是可行的，您只需要显式地接受对象实例作为所有方法的输入参数。您需要更新以下两个函数定义：

function doJobs(this)
function getJobsCompleted(this, n)

尽管如此，更好的方法可能是使用事件和听众。然后，您将让员工发出"JobCompleted“事件，并让老板为他们的所有员工收听这些事件。这就避免了员工需要跟踪他们的老板。

classdef Boss < handle

    properties
        Employees
        Listeners
    end

    methods
        function this = Boss(employees)
            this.Employees = employees;

            this.Listeners = addlistener(employees, 'JobCompleted', @this.onJobCompleted);
        end

        function onJobCompleted(this, employee, evnt)
            fprintf('%s completed a job!\n', employee.Name);
        end
    end
end

Employee.m

classdef Employee < handle

    properties
        Name
        CompletedJobs = 0
    end

    events
        JobCompleted
    end

    methods
        function this = Employee(name)
            this.Name = name;
        end

        function doJob(this)
            this.CompletedJobs = this.CompletedJobs + 1;
            notify(this, 'JobCompleted')
        end
    end
end

并把它当作：

employees(1) = Employee('Fred');
employees(2) = Employee('Bill');

boss = Boss(employees);

doJob(employees);
doJob(employees(1));