Question

I have a component which has a List<T> property. The class in the list has each of its properties decorated with a description attribute but the descriptions do not show up in the Collection Editor

In the IDE designer is there a way to turn on the Description panel in the standard Collection Editor? Will I need to inherit my own type editor from CollectionEditor to achieve this?

Answer 1

Basically, you’d either need to create your own editor, or subclass CollectionEditor and mess with the form. The latter is easier – but not necessarily pretty…

The following uses the regular collection editor form, but simply scans it for PropertyGrid controls, enabling HelpVisible.

/// <summary> /// Allows the description pane of the PropertyGrid to be shown when editing a collection of items within a PropertyGrid. /// </summary> class DescriptiveCollectionEditor : CollectionEditor {     public DescriptiveCollectionEditor(Type type) : base(type) { }     protected override CollectionForm CreateCollectionForm()     {         CollectionForm form = base.CreateCollectionForm();         form.Shown += delegate         {             ShowDescription(form);         };         return form;     }     static void ShowDescription(Control control)     {         PropertyGrid grid = control as PropertyGrid;         if (grid != null) grid.HelpVisible = true;         foreach (Control child in control.Controls)         {             ShowDescription(child);         }     } } 

To show this in use (note the use of EditorAttribute):

class Foo {     public string Name { get; set; }     public Foo() { Bars = new List<Bar>(); }     [Editor(typeof(DescriptiveCollectionEditor), typeof(UITypeEditor))]     public List<Bar> Bars { get; private set; } } class Bar {     [Description('A b c')]     public string Abc { get; set; }     [Description('D e f')]     public string Def{ get; set; } } static class Program {     [STAThread]     static void Main() {         Application.EnableVisualStyles();         Application.Run(new Form {             Controls = {                 new PropertyGrid {                     Dock = DockStyle.Fill,                     SelectedObject = new Foo()                 }             }         });     } }