重写派生类中的基类方法并激发其事件

我在基类中实现了一个类似的模式,我是这样做的:

底座:

public virtual void OnBeforeSavingRecord(object sender, EntitySavingEventArgs<T> e)
{    }

在派生类中,我正好有您使用的调用:

派生:

public override void OnBeforeSavingRecord(object sender, EntitySavingEventArgs<Bank> e)
{
    //Do something with entity item before saving
    base.OnBeforeSavingRecord(sender, e);
}

就我的情况来说,只要打电话就可以了

OnBeforeSavingRecord(this, new EntitySavingEventArgs<T>() { SavedEntity = item });

整个场景对我来说都很管用。

编辑:

使命感 OnBeforeSavingRecord 如果从派生类的实例调用它,将在派生类的重写方法中执行代码!

如果我没弄错的话,你想在方法中触发事件 Create 但希望执行派生类的事件代码。如果事件像您的情况一样被重写,则会发生这种情况。您可以使用这个简单的Console应用程序测试它:(只需复制粘贴并运行)

public class Service 
{
    public virtual event System.EventHandler<EventArgs> BeforeSavingRecord;

    public virtual void OnBeforeSavingRecord(object sender, EventArgs e)
    {
        Console.WriteLine("Base: OnBeforeSavingRecord method call");
    }

    public virtual void Create(object item)
    {
        Console.WriteLine("Base: Create method call");
        // this will call the method of the derived class! if you call it from an instance of the derived class
        OnBeforeSavingRecord(this, new EventArgs());
    }
}

public partial class BankBusiness : Service
{
    public override void OnBeforeSavingRecord(object sender, EventArgs e)
    {
        //Do something with entity item before saving
        Console.WriteLine("Derived Class OnBeforeSavingRecord CALL");

        base.OnBeforeSavingRecord(sender, e);                
    }
}

static void Main(string[] args)
{        
    BankBusiness bankBiz = new BankBusiness();

    bankBiz.Create(new object());

    Console.ReadKey();
}

@Mong Zhu你的解决方案有效,但不适用于我的方案。我想出了以下解决方案

public class Service<T> : Interface.IService<T> where T : class
{

    Interface.IService<T> implementation;

    public virtual event System.EventHandler<EntitySavingEventArgs<T>> BeforeSavingRecord;

    public virtual event System.EventHandler<EntitySavingEventArgs<T>> SavingRecord;

    public virtual event System.EventHandler<EntitySavingEventArgs<T>> RecordSaved;

    public void PopulateEvents(Interface.IService<T> _implementation)
    {
        implementation = _implementation;

        implementation.BeforeSavingRecord += new System.EventHandler<EntitySavingEventArgs<T>>(this.OnBeforeSavingRecord);
        implementation.SavingRecord += new System.EventHandler<EntitySavingEventArgs<T>>(this.OnSavingRecord);
        implementation.RecordSaved += new System.EventHandler<EntitySavingEventArgs<T>>(this.OnRecordSaved);
    }

    public virtual void OnBeforeSavingRecord(object sender, EntitySavingEventArgs<T> e)
    {

    }

    public virtual void OnSavingRecord(object sender, EntitySavingEventArgs<T> e)
    {

    }
    public virtual void OnRecordSaved(object sender, EntitySavingEventArgs<T> e)
    {

    }

    private readonly DbContext _dbContext;
    public Service(DbContext dbContext)
    {
        _dbContext = dbContext;
    }

    public virtual void Create(T item)
    {

        if (item == null)
            throw new ArgumentNullException("item");

        BeforeSavingRecord?.Invoke(this, new EntitySavingEventArgs<T>() { SavedEntity = item });
        _dbContext.Set(typeof(T)).Add(item);
        SavingRecord?.Invoke(this, new EntitySavingEventArgs<T>() { SavedEntity = item });
        _dbContext.SaveChanges();
        RecordSaved?.Invoke(this, new EntitySavingEventArgs<T>() { SavedEntity = item });

    }
}

    [Service]
public partial class BankBusiness : Service<Bank>, IBankBusiness
{
    public BankBusiness()
        : base(ContainerManager.Container.Resolve<MyContext>())
    {
        base.PopulateEvents(this);
    }


    public override void OnBeforeSavingRecord(object sender, EntitySavingEventArgs<Bank> e)
    {

        base.OnBeforeSavingRecord(sender, e);
    }
}

重点是什么

base.PopulateEvents(this);