I can't seem to find the answer to this anywhere. What default editors/converters are building into 3.5 Framework PropertyGrid control. Otherwise what object types can I throw at it and it be able to reliably show and edit? I've found a lot of tutorials on using custom editors (which I may do at some point). But right now in my program I'm allowing the user to create their own custom properties and I want to know what object types I should allow assuming they will be editing them in a PropertyGrid.
You can actually throw any object at the PropertyGrid. It will do a lot of things automatically. You only need to create custom UI type editors if you want to have a special edit experience, which is not natively provided. And even in that case you do it per property and not for a whole object.
You might want to take a look at classes that derive from UITypeEditor (in the System.Drawing.Design namespace). These types will be passed as parameters to the Editor attribute (in the System.ComponentModel namespace).
You can also look at the metadata for the type to see where the Editor attribute is applied. However, DO NOT use Reflection here, as that is not what the PropertyGrid uses.
Rather use the TypeDescriptor class to get property descriptors for the properties on the type (call the static GetProperties method). Then, with the PropertyDescriptor instance, call the GetEditor class to get an instance of the editor for that property.
The PropertyGrid uses TypeConverters and there are TypeConverters for every primitive type (as well as collections of primitive types).
As long as you're using one of the primitive types or a collection of primitive types the property grid should be able to take care of providing an editing UI.
Besides UITypeEditors, the PropertyGrid is able to display any object with a TypeConverter that returns true for CanConvertFrom(String). You can implement your own TypeConverters for specific object types in order to accomplish this.
Bear in mind that there some non-public classes.
System.Object
System.Drawing.Design.UITypeEditor
System.ComponentModel.Design.CollectionEditor
System.ComponentModel.Design.ArrayEditor
System.Web.UI.Design.CollectionEditorBase
System.Web.UI.Design.WebControls.WizardStepCollectionEditor
System.Web.UI.Design.WebControls.EmbeddedMailObjectCollectionEditor
System.Web.UI.Design.WebControls.HotSpotCollectionEditor
System.Web.UI.Design.WebControls.ListItemsCollectionEditor
System.Web.UI.Design.WebControls.MenuItemStyleCollectionEditor
System.Web.UI.Design.WebControls.RoleGroupCollectionEditor
System.Web.UI.Design.WebControls.StyleCollectionEditor
System.Web.UI.Design.WebControls.SubMenuStyleCollectionEditor
System.Web.UI.Design.WebControls.TableCellsCollectionEditor
System.Web.UI.Design.WebControls.TableRowsCollectionEditor
System.ComponentModel.Design.BinaryEditor
System.ComponentModel.Design.DateTimeEditor
System.ComponentModel.Design.MultilineStringEditor
System.ComponentModel.Design.ObjectSelectorEditor
System.Windows.Forms.Design.AnchorEditor
System.Windows.Forms.Design.BorderSidesEditor
System.Windows.Forms.Design.DockEditor
System.Windows.Forms.Design.FileNameEditor
System.Windows.Forms.Design.FolderNameEditor
System.Windows.Forms.Design.ShortcutKeysEditor
System.Web.UI.Design.ConnectionStringEditor
System.Web.UI.Design.DataBindingCollectionEditor
System.Web.UI.Design.ExpressionsCollectionEditor
System.Web.UI.Design.UrlEditor
System.Web.UI.Design.XmlFileEditor
System.Web.UI.Design.WebControls.DataGridColumnCollectionEditor
System.Web.UI.Design.WebControls.DataControlFieldTypeEditor
System.Web.UI.Design.WebControls.MenuBindingsEditor
System.Web.UI.Design.WebControls.MenuItemCollectionEditor
System.Web.UI.Design.WebControls.ParameterCollectionEditor
System.Web.UI.Design.WebControls.RegexTypeEditor
System.Web.UI.Design.WebControls.TreeNodeCollectionEditor
System.Web.UI.Design.WebControls.TreeViewBindingsEditor
System.Web.UI.Design.WebControls.DataPagerFieldTypeEditor
System.Messaging.Design.QueuePathEditor
System.Drawing.Design.ImageEditor
System.Drawing.Design.ColorEditor
System.Drawing.Design.ContentAlignmentEditor
System.Drawing.Design.CursorEditor
System.Drawing.Design.FontEditor
System.Drawing.Design.FontNameEditor
System.Drawing.Design.IconEditor
System.Workflow.ComponentModel.Design.TypeBrowserEditor
System.Workflow.ComponentModel.Design.BindUITypeEditor