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哪种结构更好,将事件处理程序作为arg传递,还是侦听事件触发?

event-handling events c#

user4134476 · 技术社区 · 7 年前

我有年龄类,当年龄值更改时,它会导致操作。我有一个Person类,它的成员变量是Age对象。

class Age
{
    private readonly EventHandler _valueChanged;

    private int _value;

    public int Value
    {
        get { return _value; }
        private set
        {
            _value = value;
            RaiseValueChangedEvent();
        }
    }

    public Age(EventHandler handler)
    {
        _valueChanged = handler;
    }

    protected void RaiseValueChangedEvent()
    {
        var handler = _valueChanged;
        if (handler != null)
        {
            handler(this, EventArgs.Empty);
        }
    }
}

class Person
{
    private readonly Age _age;

    public Person()
    {
        _age = new Age(OnAgeChanged);
    }

    protected void OnAgeChanged(object sender, EventArgs e)
    {
        // Do what is necessary.
    }
}

在我的第二个场景中,Age类有一个事件,Person类监听它的事件触发。

class Age
{
    public event EventHandler ValueChanged;

    private int _value;

    public int Value
    {
        get { return _value; }
        private set
        {
            _value = value;
            RaiseValueChangedEvent();
        }
    }

    protected void RaiseValueChangedEvent()
    {
        var handler = ValueChanged;
        if (handler != null)
        {
            handler(this, EventArgs.Empty);
        }
    }
}

class Person
{
    private readonly Age _age = new Age();

    public Person()
    {
        _age.ValueChanged += OnAgeChanged;
    }

    protected void OnAgeChanged(object sender, EventArgs e)
    {
        // Do what is necessary.
    }
}