.netvisual-studiodesigner

Turn on Description panel in the standard CollectionEditor


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?


Solution

  • 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()
                    }
                }
            });
        }
    }