Question

public class Activity
{
    public games _Games {get;set;}
    public sports _Sports {get;set;}
}

public class games : PropertyChangedBase
{
    public int player
    { 
        get;
        set; //have if- else statement
    }
}

public class sports : PropertyChangedBase
{
     public int sub{get;set;}
}

目标：当游戏玩家超过2时，我想将体育子变量更新为10.

问题：如何访问父类并更新体育类变量？

Answer 1

您需要创建Activity的实例。您还需要在其中初始化_Sports

Activity activity = new Activity();
activity._Sports = new sports();
activity._Sports.sub = 10;

或使用object tantalizer

Activity activity = new Activity
{
    _Sports = new sports()
};

activity._Sports.sub = 10;

顺便说一下，Activity不是sports的父类。 Activity将sports个对象作为成员。在您的示例中，PropertyChangedBase是games的父类。

Answer 2

您可以使用一个事件来向Activity班级发出更新时间。

public class games
{
    public event UpdatePlayerSubDelegate UpdatePlayerSub;

    public delegate void UpdatePlayerSubDelegate();
    private int _player;

    public int player
    {
        get { return _player; }
        set
        {
            _player = value;
            if (_player > 2)
            {
                // Fire the Event that it is time to update
                UpdatePlayerSub();
            }                
        }
    }          
}

在Activity类中，您可以在构造函数中注册事件，并将事件处理程序写入必要的更新。在您的情况下，分到10：

public class Activity
{
    public games _Games { get; set; }
    public sports _Sports { get; set; }

    public Activity()
    {
        this._Games = new games();
        this._Games.UpdatePlayerSub += _Games_UpdatePlayerSub;
        this._Sports = new sports();
    }

    private void _Games_UpdatePlayerSub()
    {
        if (_Sports != null)
        {
            _Sports.sub = 10;
        }
    }
}

修改我刚刚看到标记INotifyPropertyChanged。当然，您也可以使用此界面和提供的事件。按以下方式实现接口：

public class games : INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged; private int _player; public int player { get { return _player; } set { _player = value; if (_player > 2) { // Fire the Event that it is time to update PropertyChanged(this, new PropertyChangedEventArgs("player")); } } } }

并在Activity类中再次注册构造函数中的事件：

public Activity() { this._Games = new games(); this._Games.PropertyChanged += _Games_PropertyChanged; this._Sports = new sports(); }

并声明事件处理程序的主体：

private void _Games_PropertyChanged(object sender, PropertyChangedEventArgs e) { if (_Sports != null) { _Sports.sub = 10; } }

_Sports.sub会自动更新。希望能帮助到你。当然还有其他方法可以完成此更新。这是我想到的第一个

访问父级对象

2 个答案: