尽管定义了事件，但为什么我的类没有实现该接口？

Question

我目前正在了解具有以下代码的事件：

public interface INotifyMessageChanged
{
    public event EventHandler MessageChanged;
}

public class Academy : Organization, INotifyMessageChanged
{
    public event EventHandler? NotifySubScriber;

    private string message = "";
    public string Message
    {
        get { return message; }
        set { message = value; MessageChanged(); }
    }
    public Academy(string name, string address) : base(name)
    {
        Address = address;
    }

    void MessageChanged()
    {
        NotifySubScriber?.Invoke(this, nul);
    }
}

代码产生以下错误：

CS0535  'Academy' does not implement interface member 'INotifyMessageChanged.MessageChanged'

接口中的MessageChanged事件不应该和类中的事件一一对应吗？

Answer 1

您的活动签名不同：

EventHandler MessageChanged

和

EventHandler? NotifySubscriber

public interface INotifyMessageChanged
{
    public event EventHandler MessageChanged;
}

public class Academy : Organization, INotifyMessageChanged
{
    public event EventHandler MessageChanged;

    private string message = "";
    public string Message
    {
        get { return message; }
        set { message = value; this.OnMessageChanged(); }
    }
    public Academy(string name, string address) : base(name)
    {
        Address = address;
    }

    void OnMessageChanged()
    {
        this.MessageChanged?.Invoke(this, null);
    }
}