List<PClass> P = new List<PClass> { new PClass() {programme="PROG 1" , idP = 1, LibP = "P1-AA" },
                                                new PClass() {programme="PROG 1", idP = 2, LibP = "P1-BB" },
                                                new PClass() {programme="PROG 2", idP = 3, LibP = "P2-CC" },
                                                new PClass() {programme="PROG 2", idP = 4, LibP = "P2-DD" },
                                                new PClass() {programme="PROG 2", idP = 5, LibP = "P2-EE" }
                                              };



            List<Cclass> C = new List<Cclass> { new Cclass() { idC = 1, idP = 1, LibC = "a" },
                                                new Cclass() { idC = 2, idP = 1, LibC = "aa" },
                                                new Cclass() { idC = 3, idP = 1, LibC = "aaa" },
                                                new Cclass() { idC = 4, idP = 2, LibC = "p1-b" },
                                                new Cclass() { idC = 5, idP = 2, LibC = "p1-bb" },
                                                new Cclass() { idC = 6, idP = 3, LibC = "p2-c" },
                                                new Cclass() { idC = 7, idP = 4, LibC = "p2-d" },
                                                new Cclass() { idC = 8, idP = 4, LibC = "p2-dd" },
                                                new Cclass() { idC = 9, idP = 4, LibC = "p2-ddd" },
                                                new Cclass() { idC = 10, idP = 5, LibC = "p2-e" },
                                                new Cclass() { idC = 11, idP = 5, LibC = "p2-ee" }
                                                };

rg.DataSource = P;
gridViewTemplate1.DataSource = C;

            
            this.FSaveAs.Name = "FSaveAs";
            this.FSaveAs.Text = "Save As";
            this.FSaveAs.Click += new System.EventHandler(this.FSaveAs_Click);
            this.FSaveAs.Shortcuts.Add(new RadShortcut(Keys.Control, Keys.Shift, Keys.S));

private static void FixTheme(Theme theme)
{
    // try to add registration
    var sg = theme.FindStyleGroup(typeof(RadPropertyGrid).FullName);
    sg.Registrations.Add(new MyStyleRegistration
    {
        RegistrationType = "ElementTypeControlType",
        ElementType      = "Telerik.WinControls.RootRadElement",
        ControlType      = typeof(ExRadPanel).FullName
    });
    sg.Registrations.Add(new MyStyleRegistration
    {
        RegistrationType = "ElementTypeControlType",
        ElementType      = typeof(RadPanelElement).FullName,
        ControlType      = typeof(ExRadPanel).FullName
    });

    var copy = sg.PropertySettingGroups.ToArray();
    foreach (var settingGroup in copy)
    {
        if (settingGroup.Selector is null)
            continue;
        if (settingGroup.Selector.Value != nameof(PropertyGridHelpElement))
            continue;
        {
            // trying this ... 
            var newSg = new PropertySettingGroup
            {
                Selector = new ElementSelector(settingGroup.Selector.Type, nameof(RadPanelElement)),
                BasedOn  = settingGroup.BasedOn
            };
            newSg.Repositories.AddRange(settingGroup.Repositories);
            newSg.PropertySettings.AddRange(settingGroup.PropertySettings);
            sg.PropertySettingGroups.Add(newSg);
        }
        {
            // ... and this    
            var newIi = new PropertySettingGroup
            {
                Selector = new ElementSelector(ElementSelectorTypes.TypeSelector, typeof(FillPrimitive).FullName),
                BasedOn  = settingGroup.BasedOn
            };
            newIi.Repositories.AddRange(settingGroup.Repositories);
            newIi.PropertySettings.AddRange(settingGroup.PropertySettings);
            sg.PropertySettingGroups.Add(newIi);
        }
    }
}

 public class MyTypeConverter : TypeConverter
    {
        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
        {
            if (destinationType.Equals(typeof(Image)))
                return true;

            return base.CanConvertTo(context, destinationType);
        }

        public override object ConvertTo(ITypeDescriptorContext context,
            System.Globalization.CultureInfo culture, object value, Type destinationType)
        {
            if (destinationType.Equals(typeof(Image)))
            {
                WebRequest request = System.Net.WebRequest.Create(value + "");

                using (var response = request.GetResponse())
                {
                    using (var stream = response.GetResponseStream())
                    {
                        return Bitmap.FromStream(stream);
                    }
                }
            }
            return base.ConvertTo(context, culture, value, destinationType);
        }
    }