//FlyGrid initialization procedure
private void InitGrid(FlyGrid flyGrid)
{
  //....
  //connect to the NodeExpandChange event handler
  flyGrid.NodeExpandChange += new NodeHandler(flyGrid_NodeExpandChange);
}
// NodeExpandChange event handler
private void flyGrid_NodeExpandChange(object sender, NodeBase node)
{
   INestedGridNode nested = node as INestedGridNode;
   if (nested != null && node.Expanded)
   {
     FlyGridViewPort port = nested.NestedInternal;
     port.VScrollBarEnabled = false;
   }
}

[C#]
public class ButtonColumnWithBoundImages : ButtonColumn
{
   public ButtonColumnWithBoundImages() : base(){}
   public ButtonColumnWithBoundImages(string name) : base(name){}
   public ButtonColumnWithBoundImages(string name, string fieldName) : base(name, fieldName){}
   private string imageField = string.Empty;
   [DefaultValue("")]
   public string ImageField
   {
     get {return imageField;}
     set
     {
       if (imageField != value)
       {
         imageField = value;
         base.OnChanged(InvalidationMode.ColumnWithoutHeader, false);
       }
     }
   }
   protected override Image GetButtonImage(NodeBase node)
   {
     if (ImageField != null && ImageField != string.Empty)
     {
       DataRowView dr = node.Value as DataRowView;
       if (dr != null)
       {
         byte[] arr = dr[ImageField] as byte[];
         if (arr != null)
         {
           Image img = Image.FromStream(new System.IO.MemoryStream(arr));
           if (img != null)
             return img;
         }
       }
     }
     return base.GetButtonImage(node);
   }
}

[c#]
public static NodeBase[] GetCheckedNodes(NodeCollection nodes, bool includeChildren)
{
   ArrayList al = new ArrayList();
   foreach(NodeBase node in nodes)
   {
     if (node.Checked)
       al.Add(node);
     if (includeChildren && node.HasChildren)
       al.AddRange(GetCheckedNodes(node.Items, includeChildren));
   }
   return al.ToArray(typeof(NodeBase)) as NodeBase[];
}

[c#]
public NodeBase[] GetCheckedNodes(FlyGrid flyGrid)
{
   return GetCheckedNodes(flyGrid.Rows.Items, true);
}

[c#]
using NineRays.Windows.Forms;
using NineRays.Windows.Forms.Data;
using NineRays.Windows.Forms.Grids;
using NineRays.Windows.Drawing;
//....
private void Form1_Load(object sender, System.EventArgs e)
{
  InitFlyGrid(flyGrid);
}

public class BoundCheckBoxColumn : HierachyColumn
{
  public BoundCheckBoxColumn(string name) : base(name){}          
  public BoundCheckBoxColumn(string name, string fieldName) : base(name, fieldName){}
  private string checkBoxFieldName = string.Empty;
  [DefaultValue(\"\")]
  public string CheckBoxFieldName
  {
    get
    {
      return checkBoxFieldName;
    }
    set
    {
      if (checkBoxFieldName != value)
      {
        checkBoxFieldName = value;
        base.OnChanged(InvalidationMode.FullColumn, false);
      }
    }
  }
  
  public override void OnCheckBoxClick(FlyGrid flyGrid, NodeBase node)
  {
    if (CheckBoxesReadOnly && CheckBoxFieldName != string.Empty)
    {
      CheckBoxState cbs = GetCheckBoxstate(node);
      DataRowView drv = node.Value as DataRowView;
      if (drv != null)
      {
        if ((cbs & CheckBoxState.Checked) != 0)
          cbs &= ~CheckBoxState.Checked;
        else
          cbs |= CheckBoxState.Checked;
      
        if ((cbs & CheckBoxState.Grayed) != 0)
          cbs &= ~CheckBoxState.Grayed;

        drv[CheckBoxFieldName] = cbs;
      }
    }
    else
    {
      base.OnCheckBoxClick(flyGrid, node);
    }
  }

  protected override CheckBoxState GetCheckBoxstate(NodeBase node)
  {
    if (CheckBoxFieldName != string.Empty)
    {
      DataRowView drv = node.Value as DataRowView;
      if (drv != null)
      {
        object cellvalue = drv[CheckBoxFieldName];
        return cellvalue != null && cellvalue != DBNull.Value ?
          (CheckBoxState)cellvalue :
          CheckBoxState.None;            
      }
    }
    return base.GetCheckBoxstate (node);
  }      
}

private void InitFlyGrid(FlyGrid flyGrid)
{
  flyGrid.BeginInit();
  try
  {
    BoundCheckBoxColumn boundCheckBoxColumn = new BoundCheckBoxColumn(\"Value\");
    //setup column
    boundCheckBoxColumn.CheckBoxFieldName = \"CheckBoxValue\";
    boundCheckBoxColumn.ShowCheckBoxes = true;
    //fit to width
    boundCheckBoxColumn.FitMode = ColumnFitMode.Spring;        
    flyGrid.Columns.Options |= ColumnsOptions.FitToWidth;
    //hide AddNewRow row
    flyGrid.Rows.Options &= ~ RowsOptions.ShowAddNewRow;
    //add column
    flyGrid.Columns.Items.Add(boundCheckBoxColumn);
    //create and setup datatable
    DataTable dt = new DataTable(\"Data\");
    DataColumn dc = new DataColumn(\"Value\", typeof(string));
    DataColumn dcb = new DataColumn(\"CheckBoxValue\", typeof(ButtonState));
    dt.Columns.Add(dc);
    dt.Columns.Add(dcb);
    //fill data
    for(int i=0; i < 10; i++)
    {
      object[] rowdata =
          {
            \"new row\" + i,
            i % 2 == 0 ? CheckBoxState.Checked : CheckBoxState.Checked | CheckBoxState.Grayed
          };
      dt.Rows.Add(rowdata);
    }
    flyGrid.Rows.DataSource = dt;
  }
  finally
  {
    flyGrid.EndInit();
  }
}