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POPropertyGrid - Property derived from IList<T>, How do I add to the PropertyGrid so user can Add/Edit/Remove items
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  1. POPropertyGrid - Property derived from IList<T>, How do I add to the PropertyGrid so user can Add/Edit/Remove items
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    copied!<p>Let me provide a bit of a history as to how I've reached this point.</p> <p>I originally had a Property within my class that derived from CollectionsBase and had this collection mapped to the PropertyGrid and the user could Add/Edit/Remove items from the list at will.</p> <p>However, I couldn't map the CollectionsBase with NHibernate, thus I had to scrap my initial implementation and instead of deriving from CollectionsBase, I had the class derive from IList.</p> <p>Now I can map to NHibernate, but I am unable to edit the collection via the PropertyGrid.</p> <p>I need some help getting the 2 to play nice with each other.</p> <p>In my main class I have a property defined as:</p> <pre><code> public virtual ZoneCollection Zones { get { return zones; } set { zones = value; } } </code></pre> <p>My Zone Collection that inherits IList is defined as follows:</p> <pre><code>public class ZoneCollection : IList&lt;Zone&gt;, ICustomTypeDescriptor { private IList&lt;Zone&gt; _list; public IList&lt;Zone&gt; _List { get { return _list; } } public ZoneCollection() { _list = new List&lt;Zone&gt;(); } #region Implementation of IEnumerable public IEnumerator&lt;Zone&gt; GetEnumerator() { return _list.GetEnumerator(); } IEnumerator IEnumerable.GetEnumerator() { return GetEnumerator(); } #endregion #region Implementation of ICollection&lt;Zone&gt; public void Add(Zone item) { _list.Add(item); } public void Clear() { _list.Clear(); } public bool Contains(Zone item) { return _list.Contains(item); } public void CopyTo(Zone[] array, int arrayIndex) { _list.CopyTo(array, arrayIndex); } public bool Remove(Zone item) { return _list.Remove(item); } public int Count { get { return _list.Count; } } public bool IsReadOnly { get { return false; } } #endregion #region Implementation of IList&lt;Zone&gt; public int IndexOf(Zone item) { return _list.IndexOf(item); } public void Insert(int index, Zone item) { _list.Insert(index, item); } public void RemoveAt(int index) { _list.RemoveAt(index); } public Zone this[int index] { get { return (Zone)_list[index]; } set { _list[index] = value; } } #endregion // Implementation of interface ICustomTypeDescriptor #region ICustomTypeDescriptor impl public String GetClassName() { return TypeDescriptor.GetClassName(this, true); } public AttributeCollection GetAttributes() { return TypeDescriptor.GetAttributes(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 object GetEditor(Type editorBaseType) { return TypeDescriptor.GetEditor(this, editorBaseType, true); } public EventDescriptorCollection GetEvents(Attribute[] attributes) { return TypeDescriptor.GetEvents(this, attributes, true); } public EventDescriptorCollection GetEvents() { return TypeDescriptor.GetEvents(this, true); } public object GetPropertyOwner(PropertyDescriptor pd) { return this; } /// &lt;summary&gt; /// Called to get the properties of this type. Returns properties with certain /// attributes. this restriction is not implemented here. /// &lt;/summary&gt; /// &lt;param name="attributes"&gt;&lt;/param&gt; /// &lt;returns&gt;&lt;/returns&gt; public PropertyDescriptorCollection GetProperties(Attribute[] attributes) { return GetProperties(); } /// &lt;summary&gt; /// Called to get the properties of this type. /// &lt;/summary&gt; /// &lt;returns&gt;&lt;/returns&gt; public PropertyDescriptorCollection GetProperties() { // Create a collection object to hold property descriptors PropertyDescriptorCollection pds = new PropertyDescriptorCollection(null); // Iterate the list of zones for (int i = 0; i &lt; this._list.Count; i++) { // Create a property descriptor for the zone item and add to the property descriptor collection ZoneCollectionPropertyDescriptor pd = new ZoneCollectionPropertyDescriptor(this, i); pds.Add(pd); } // return the property descriptor collection return pds; } #endregion } /// &lt;summary&gt; /// Summary description for CollectionPropertyDescriptor. /// &lt;/summary&gt; public class ZoneCollectionPropertyDescriptor : PropertyDescriptor { private ZoneCollection collection = null; private int index = -1; public ZoneCollectionPropertyDescriptor(ZoneCollection coll, int idx) : base("#" + idx.ToString(), null) { this.collection = coll; this.index = idx; } public override AttributeCollection Attributes { get { return new AttributeCollection(null); } } public override bool CanResetValue(object component) { return true; } public override Type ComponentType { get { return this.collection.GetType(); } } public override string DisplayName { get { Zone zone = this.collection[index]; return zone.ID.ToString(); } } public override string Description { get { Zone zone = this.collection[index]; StringBuilder sb = new StringBuilder(); sb.Append(zone.ID.ToString()); if (zone.Streets.Route != String.Empty || zone.Streets.Crossing != String.Empty) sb.Append("::"); if (zone.Streets.Route != String.Empty) sb.Append(zone.Streets.Route); if (zone.Streets.Crossing != String.Empty) { sb.Append(" and "); sb.Append(zone.Streets.Crossing); } return sb.ToString(); } } public override object GetValue(object component) { return this.collection[index]; } public override bool IsReadOnly { get { return false; } } public override string Name { get { return "#" + index.ToString(); } } public override Type PropertyType { get { return this.collection[index].GetType(); } } public override void ResetValue(object component) { } public override bool ShouldSerializeValue(object component) { return true; } public override void SetValue(object component, object value) { // this.collection[index] = value; } } </code></pre> <p>}</p> <p>Now, my ICustomTypeDescriptor and PropertyDescriptor worked fine when this class derived from CollectionsBase, but now it just shows the class name ZoneCollection in the property name without the "..." button to add/edit/remove the items from the list.</p> <p>What am I doing wrong now that it is inherited from IList that this isn't working?</p> <p>If I add:</p> <pre><code>[TypeConverter(typeof(ExpandableObjectConverter))] </code></pre> <p>To the beginning of the ZoneCollection, I get the items in the list listed in an expandable tree, but that's not what I am looking for. Where did the "..." button go that opened up a popup window that enabled me to add/edit/remove the items in the collection when I inherited from IList instead of CollectionBase?</p>
 

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