xtraScrollableControlスクロールバーをマウスでスクロール

コードは次のとおりです.

//



using System;

using System.Windows.Forms;

using DevExpress.XtraEditors;



namespace WindowsFormsApplication1 {

    public class ScrollHelper {



        readonly XtraScrollableControl _scrollableControl;



        public ScrollHelper(XtraScrollableControl scrollableControl) { _scrollableControl = scrollableControl; }



        public void EnableScrollOnMouseWheel() { _scrollableControl.VisibleChanged += OnVisibleChanged; }



        void OnVisibleChanged(object sender, EventArgs e) {

            _scrollableControl.Select();

            UnsubscribeFromMouseWheel(_scrollableControl.Controls);

            SubscribeToMouseWheel(_scrollableControl.Controls);

        }



        public void SubscribeToMouseWheel(Control.ControlCollection controls) {

            foreach (Control ctrl in controls) {

                ctrl.MouseWheel += OnMouseWheel;

                SubscribeToMouseWheel(ctrl.Controls);

            }

        }



        public void UnsubscribeFromMouseWheel(Control.ControlCollection controls)

        {

            foreach (Control ctrl in controls) {

                ctrl.MouseWheel -= OnMouseWheel;

                UnsubscribeFromMouseWheel(ctrl.Controls);

            }

        }



        void OnMouseWheel(object sender, MouseEventArgs e) {

            DevExpress.Utils.DXMouseEventArgs.GetMouseArgs(e).Handled = true;

            var scrollValue = _scrollableControl.VerticalScroll.Value;

            var largeChange = _scrollableControl.VerticalScroll.LargeChange;

            if (e.Delta < 0)

                _scrollableControl.VerticalScroll.Value += _scrollableControl.VerticalScroll.LargeChange;

            else

                if (scrollValue < largeChange) { _scrollableControl.VerticalScroll.Value = 0; }

                else { _scrollableControl.VerticalScroll.Value -= largeChange; }

        }



        public void DisableScrollOnMouseWheel() {

            _scrollableControl.VisibleChanged -= OnVisibleChanged;

            UnsubscribeFromMouseWheel(_scrollableControl.Controls);

        }



    }

}

実行コード
 

private ScrollHelper _scrollHelper;





        public  ()

        {

            InitializeComponent();



            _scrollHelper = new ScrollHelper(xtraScrollableControl1);

            _scrollHelper.EnableScrollOnMouseWheel();

        }

ただし、コントロールがフォーカスを取得していないと機能しません.