.net 使用ObservableCollection订阅CollectionChanged事件

当我创建一个

可观察集合

时，如何在添加或删除项目时运行附加逻辑

Public Property Employees As ObservableCollection(Of employee)
    Get
        If _employees Is Nothing Then
            _employees = New ObservableCollection(Of employee)
            AddHandler _employees.CollectionChanged, AddressOf OnEmployeesChanged
        End If
        Return _employees 
    End Get
    Set(ByVal value As ObservableCollection(Of employee))
        _employees = value
    End Set
End Property

Private _employees As ObservableCollection(Of employee)

Protected Sub OnEmployeesChanged()
   'addtional logic...
End Sub

当我打电话时

Employees.Add

或

-->一个被解雇的员工不会被解雇，塞特也不会

员工必须通知集合已更改（WPF UI绑定到该集合），但我不想使用两行代码触发事件

_employees.Add
RaisePropertyChanged("Employees")

---

属性的结构应该如何处理这个问题？

我不知道VB，但这里是c#，我相信您可以翻译它

TheList.CollectionChanged += TheList_CollectionChanged;

private void TheList_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (e.NewItems != null)
        {
            foreach (string model in e.NewItems)
            {
              //do something when an item is added to the collection
            }
        }
        if (e.OldItems != null)
        {
            foreach (string model in e.OldItems)
            {
               //do something when an item is removed here
            }
        }
    }

---

在将任何项目添加到集合之前，请确保注册CollectionChanged事件。您的代码应该有效；您是否正确实施了方法

OnEmployeesChanged

？我的意思是该方法的签名应该是

受保护的Sub-OnEmployeesChanged（发送者作为对象，e作为NotifyCollectionChangedEventArgs）

TheList.CollectionChanged += TheList_CollectionChanged;

private void TheList_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (e.NewItems != null)
        {
            foreach (string model in e.NewItems)
            {
              //do something when an item is added to the collection
            }
        }
        if (e.OldItems != null)
        {
            foreach (string model in e.OldItems)
            {
               //do something when an item is removed here
            }
        }
    }