hi,

thank you for your reply.

i have created the properties for selecteditem and event handler for selectionchanged as shown. But the issue is comboeditortool.selecteditem is always null. Can you please let me know the issue in the following code?

public class XamComboEditorTool : RibbonTool
    {
        private XamComboEditorToolControl _control;

        public XamComboEditorToolControl Control
        {
            get { return _control; }
            set { _control = value; }
        }

        private void UpdateBindings()
        {
            if (this._control != null)
            {
                this._control.OnApplyTemplate();
            }
        }

        protected override RibbonToolBaseControl ResolveToolControl()
        {
            XamComboEditorToolControl control = new XamComboEditorToolControl(this);
            if (this._control == null)
            {
                this._control = control;
            }
            return control;
        }

        public IEnumerable ItemsSource
        {
            get { return (IEnumerable)GetValue(ItemsSourceProperty); }
            set
            {
                SetValue(ItemsSourceProperty, value);
                this.UpdateBindings();
            }
        }

        public static readonly DependencyProperty ItemsSourceProperty =
            DependencyProperty.Register("ItemsSource", typeof(IEnumerable),
            typeof(XamComboEditorTool), null);

        public String DisplayMemberPath { get; set; }

        public object SelectedItem
        {
            get { return (object)GetValue(SelectedItemProperty); }
            set
            {
                SetValue(SelectedItemProperty, value);
                this.UpdateBindings();
            }
        }

        public static readonly DependencyProperty SelectedItemProperty =
            DependencyProperty.Register("SelectedItem", typeof(object), typeof(XamComboEditorTool),
             new PropertyMetadata(null));

        public event EventHandler SelectionChanged;

        public void SelectionChangedEventHandler(object sender, EventArgs e)
        {
            if (SelectionChanged != null) SelectionChanged(sender, e);
        }
    }

    public class XamComboEditorToolControl : RibbonToolBaseControl, IRibbonControl
    {
        private XamComboEditor _combo;

        public XamComboEditor Combo
        {
            get { return _combo; }
            set { _combo = value; }
        }

        public XamComboEditorToolControl()
        {
            this.DefaultStyleKey = typeof(XamComboEditorToolControl);
        }

        public XamComboEditorToolControl(RibbonToolBase tool)
            : base(tool)
        {
            this.DefaultStyleKey = typeof(XamComboEditorToolControl);
        }

        public override void OnApplyTemplate()
        {
            base.OnApplyTemplate();
            this._combo = GetTemplateChild("XamComboEditor") as XamComboEditor;
            if (this._combo != null)
            {
                this._combo.ItemsSource = ((XamComboEditorTool)this.Tool).ItemsSource;
                this._combo.DisplayMemberPath = ((XamComboEditorTool)this.Tool).DisplayMemberPath;
                this._combo.SelectionChanged += new EventHandler(((XamComboEditorTool)this.Tool).SelectionChangedEventHandler);
                this._combo.SelectedItem = ((XamComboEditorTool)this.Tool).SelectedItem;
            }
        }           
        
    }