Prevent editing items within dropdown element of propertygrid

Question

I have the following code which displays a dropdown list of selectable items in a propertygrid which generally works fine. However, the dropdown allows the items within the dropdown to be edited which causes an error on 'System.ComponentModel.EnumConverter.ConvertFrom' as its not a valid enum. For example, Option1 can be changed to OptionABC1 which I want to prevent.

There is a flag on PropertyStoreItem to set it to read only but this prevents the whole property being changed rather than preventing editing of the dropdown items.

How do I make the dropdown non-editable but still allow the fixed list to be selected? It might be a property on the propertygrid I need to change but cannot find it.

[Flags]
Public Enum SomePropertyTypes
{
    Option1 = 1,
    Option2 = 2,
    Option3 = 4,
    Option4 = 8,
    Option5 = 16,
    Option6 = 32
}

public partial class AddSomePropertyForm : RadForm
{
    private RadPropertyStore store;

    Public AddSomePropertyForm()
    {
        InitializeComponent();
        this.store = this.CreatePropertyStore();
        this.radPropertyGrid1.SelectedObject = store;
    }

    private RadPropertyStore CreatePropertyStore()
    {
        RadPropertyStore somePropertyStore = new RadPropertyStore();
        PropertyStoreItem somePropertyType = new PropertyStoreItem(typeof(SomePropertyTypes), "PropertyName", SomePropertyTypes.Option1, "Property Info", "Group1", false);
        somePropertyStore.Add(somePropertyType);
        return somePropertyStore;
    }
}

Answer 1

You should customize the drop down editor behavior by using the EditorInitialized event.

   void radPropertyGrid1_EditorInitialized(object sender, PropertyGridItemEditorInitializedEventArgs e)
    {
        PropertyGridDropDownListEditor editor = e.Editor as PropertyGridDropDownListEditor;
        if (editor != null)
        {
            editor.DropDownStyle = RadDropDownStyle.DropDownList;
        }
    }

Here is an article on the matter: link