public abstract class VirtualGrid : Control
    {
        public VirtualGrid() {}

        private bool _RowsHeightConst = true;
        public bool RowsHeightConst
        {
            get { return _RowsHeightConst; }
            set { _RowsHeightConst = value; }
        }

        private bool _ColumnsHeightConst = false;
        public bool ColumnsHeightConst
        {
            get { return _ColumnsHeightConst; }
            set { _ColumnsHeightConst = value; }
        }

        private VGColumnCollection _Columns = new VGColumnCollection();
        public VGColumnCollection Columns
        {
            get { return _Columns; }
            set { _Columns = value; }
        }

        private IVGDataSource _DataSource = null;
        public IVGDataSource DataSource
        {
            get { return _DataSource; }
            set { _DataSource = value; }
        }
    
        private VGHorScroller _HorScroller;
        public HorScroller HorScroller
        {
            get { return _HorScroller; }
            set { _HorScroller = value; }
        }

        private VGVertScroller _VertScroller;
        public VGVertScroller VertScroller
        {
            get { return _VertScroller; }
            set { _VertScroller = value; }
        }
    
    }

    public interface IVGDataSource
    {
        int RowsCount { get; }
        object GetData(int Row);
        event EventHandler DataChanged;
    }

    public class VGColumn
    {
        public VGColumn()
        {
        }

        private string _Name;
        public string Name
        {
            get {return _Name; }
            set { _Name = value; }
        }

        private string _Title;
        public string Title
        {
            get { return _Title; }
            set { _Title = value; }
        }
    }
    
    public class VGColumnCollection : CollectionBase
    {
        public VGColumnCollection()
        {
        }

        public VGColumn this[int index]
        {
            get { return (VGColumn)List[index]; }
            set { List[index] = value; }                                        
        }

        public VGColumn this[string Name]
        {
            get { return null; }
            set { }
        }
    }

    public abstract class VGScroller
    {
        public VGScroller()
        {
        }

        protected int _MaxSize;
        public int MaxSize
        {
            get { return _MaxSize; }
            set { _MaxSize = value; }
        }

        protected int _MinSize;
        public int MinSize
        {
            get { return _MinSize; }
            set { _MinSize = value; }
        }

        protected int _Value;
        public int Value
        {
            get { return _Value; }
            set
            {
                _Value = value;
                OnValueChanged();
            }
        }

        public event EventHandler ValueChanged;
        protected void OnValueChanged()
        {
            if (ValueChanged != null)
                ValueChanged(this, new EventArgs());
        }
    }

public class VGGorScroller : VGScroller { /*...*/ }
public class VGVerScroller : VGScroller { /*...*/ }

    interface IVirtualGrid
    {
        int RowsCount
        {
            get;
            set;
        }

        int TopRow
        {
            get;
            set;
        }

        bool CacheRowsHeight
        {
            get;
            set;
        }

        int GetBottomRow();

    }

SAV>    public interface IVGDataSource
SAV>    {
SAV>        int RowsCount { get; }
SAV>        object GetData(int Row);
SAV>        event EventHandler DataChanged;
SAV>    }
SAV>

// удобнее писать 
clmName.ForeColor = Color.Red;
// чем 
grid.Columns["Name"].ForeColor = Color.Red;

clmHeader1|clmHeader2|clmHeader3...
--------------------------------[^]
--------------------------------[|]
--------------------------------[|]
--------------------------------[|]
--------------------------------[v]
[<----------------------------->...

clmHeader1|clmHeader2|clmHeader3...
--------------------------------[^]
--------------------------------[|]
--------------------------------[|]
--------------------------------[|]
--------------------------------[v]
[<----------------------------->...

clmHeader1|clmHeader2|clmHeader3[^]
--------------------------------[|]
--------------------------------[|]
--------------------------------[|]
--------------------------------[|]
--------------------------------[v]
[<----------------------------->...

int GetRowAt(int x, int y); // для хит-тестов разных, например для драг-дропа
int GetRowBottom(int index); // для выпадающего меню, чтобы строку не загораживало
void ScrollRowIntoView(int index); // для программного показа строки, например свежедобавленой