正确捕获OnCollectionChanged和OnPropertyChanged事件

Question

首先，没有关于使用CollectionBase作为基类的评论。我知道，我知道......

我有以下内容：

using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Diagnostics;
using System.Collections.Specialized;

namespace PropertyGridSample
{
    [TypeConverter(typeof(LayerConverter))]
    public class Layer
    {
        public Image image { get; set; }

        public Layer() { }
    }

    public class Layers
    {
        LayerCollection layercollection { get; set; }

        public Layers()
        {
            layercollection = new LayerCollection();

            Layer[] layz = new Layer[2];

            Layer lay1 = new Layer(); Layer lay2 = new Layer(); //Create two test layers and add them to the layer collection

            layercollection.Add(lay1); layercollection.Add(lay2);
        }

        [TypeConverter(typeof(LayerCollectionConverter))]
        public LayerCollection Layer_Collection { get { return layercollection; } }
    }

    public class LayerCollection : CollectionBase, ICustomTypeDescriptor, INotifyCollectionChanged, INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;
        protected virtual void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
            Debug.Write(propertyName);
        }

        public event NotifyCollectionChangedEventHandler CollectionChanged;

        protected virtual void OnCollectionChanged(NotifyCollectionChangedEventArgs e)
        {
            if (CollectionChanged != null)
            {
                CollectionChanged(this, e);
            }

            Debug.Write("Will Never show, when built in collection editor is used.");
        }

        #region collection impl
        public void Add(Layer lay) { List.Add(lay); OnPropertyChanged("ADDLAYER"); OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, 0));  } //Adds a layer object to the collection
            public void Remove(Layer lay) { List.Remove(lay); OnPropertyChanged("REMOVELAYER"); OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, 0));  } //Removes a layer object from the collection

            public Layer this[int index] { get { return (List.Count > -1 && index < List.Count) ? (Layer)List[index] : null; } } //Return a layer object at index position
        #endregion

        #region ICustomTypeDescriptor impl 
            public AttributeCollection GetAttributes() { return TypeDescriptor.GetAttributes(this, true); }

            public String GetClassName() { return TypeDescriptor.GetClassName(this, true); }
            public String GetComponentName() { return TypeDescriptor.GetComponentName(this, true); }

            public TypeConverter GetConverter() { return TypeDescriptor.GetConverter(this, true); }

            public EventDescriptor GetDefaultEvent() { return TypeDescriptor.GetDefaultEvent(this, true); }
            public PropertyDescriptor GetDefaultProperty() { return TypeDescriptor.GetDefaultProperty(this, true); }

            public EventDescriptorCollection GetEvents(Attribute[] attributes) { return TypeDescriptor.GetEvents(this, attributes, true); }
            public EventDescriptorCollection GetEvents() { return TypeDescriptor.GetEvents(this, true); }

            public object GetEditor(Type editorBaseType) { return TypeDescriptor.GetEditor(this, editorBaseType, true); }
            public object GetPropertyOwner(PropertyDescriptor pd) { return this; }

            //Called to get the properties of this type. Returns properties with certain attributes. this restriction is not implemented here.
            public PropertyDescriptorCollection GetProperties(Attribute[] attributes) { return GetProperties(); }

            //Called to get the properties of this type.
            public PropertyDescriptorCollection GetProperties()
            {            
                PropertyDescriptorCollection pds = new PropertyDescriptorCollection(null); // Create a collection object to hold property descriptors

                // Iterate the list of layers and create a property descriptor for each layer item and add to the property descriptor collection
                for (int i = 0; i < this.List.Count; i++) { LayerCollectionPropertyDescriptor pd = new LayerCollectionPropertyDescriptor(this, i); pds.Add(pd); }

                return pds; // return the descriptor collection
            }
        #endregion
    }

    class LayerConverter : ExpandableObjectConverter
    {
        public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destType)
        {
            return (destType == typeof(string) && value is Layer) ? "Layer Data": base.ConvertTo(context, culture, value, destType);
        }
    }

    class LayerCollectionConverter : ExpandableObjectConverter
    {
        public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destType)
        {
            return  (destType == typeof(string) && value is LayerCollection) ? "Items": base.ConvertTo(context, culture, value, destType);
        }
    }

    public class LayerCollectionPropertyDescriptor : PropertyDescriptor
    {
        private LayerCollection collection = null;
        private int index = -1;

        public LayerCollectionPropertyDescriptor(LayerCollection coll, int idx) : base("#" + idx.ToString(), null)
        {
            collection = coll; index = idx;
        }

        public override AttributeCollection Attributes { get { return new AttributeCollection(null); } }

        public override bool CanResetValue(object component) { return true; }
        public override bool IsReadOnly { get { return false; } }
        public override bool ShouldSerializeValue(object component) { return true; }

        public override string Description { get { return "Layer Description"; } }
        public override string DisplayName { get { return "Layer " + index.ToString(); } }
        public override string Name { get { return "#" + index.ToString(); } }

        public override object GetValue(object component) { return collection[index]; }

        public override Type ComponentType { get { return collection.GetType(); } }
        public override Type PropertyType { get { return collection[index].GetType(); } }

        public override void ResetValue(object component) { }
        public override void SetValue(object component, object value) { } // this.collection[index] = value;
    }
}

在LayerCollection类中，我尝试添加更改通知。在我的主窗体中，我想为OnCollectionChanged和OnPropertyChanged事件分配一个函数。但是......首先，我有一个问题。我只收到了收藏品和财产变更事件，一旦启动。因为，我手动添加两个项目到集合。只是为了测试。无论如何，如果我使用内置的集合编辑器：

如果我使用它添加或删除项目，则不会触发事件。我真的需要，事件。尤其是曝光，以后以我的主要形式捕捉。