/// <summary>
/// the main difference with a Group row and a regular row is the way it is painted on the control.
/// the Paint method is therefore overridden and specifies how the Group row is painted.
/// Note: this method is not implemented optimally. It is merely used for demonstration purposes
/// </summary>
/// <param name="graphics"></param>
/// <param name="clipBounds"></param>
/// <param name="rowBounds"></param>
/// <param name="rowIndex"></param>
/// <param name="rowState"></param>
/// <param name="isFirstDisplayedRow"></param>
/// <param name="isLastVisibleRow"></param>
protected override void Paint(System.Drawing.Graphics graphics, System.Drawing.Rectangle clipBounds, System.Drawing.Rectangle rowBounds, int rowIndex, DataGridViewElementStates rowState, bool isFirstDisplayedRow, bool isLastVisibleRow)
{
if (IsGroupRow)
{
DataGridViewGroup group = Tag as DataGridViewGroup;
TreeDataGridView grid = (TreeDataGridView)this.DataGridView;
int rowHeadersWidth = grid.RowHeadersVisible ? grid.RowHeadersWidth : 0;
// this can be optimized
Brush brush = new SolidBrush(grid.DefaultCellStyle.BackColor);
Brush brush2 = new SolidBrush(Color.FromKnownColor(KnownColor.GradientActiveCaption));
int gridwidth = grid.Columns.GetColumnsWidth(DataGridViewElementStates.Displayed);
Rectangle rowBounds2 = grid.GetRowDisplayRectangle(this.Index, true);
// draw the background
graphics.FillRectangle(brush, rowBounds.Left + rowHeadersWidth - grid.HorizontalScrollingOffset, rowBounds.Top, gridwidth, rowBounds.Height - 1);
// draw text, using the current grid font
graphics.DrawString(group != null ? group.Header : "", grid.Font, Brushes.Black, rowHeadersWidth - grid.HorizontalScrollingOffset + 23, rowBounds.Bottom - 18);
//draw bottom line
graphics.FillRectangle(brush2, rowBounds.Left + rowHeadersWidth - grid.HorizontalScrollingOffset, rowBounds.Bottom - 2, gridwidth - 1, 2);
// draw right vertical bar
if (grid.CellBorderStyle == DataGridViewCellBorderStyle.SingleVertical || grid.CellBorderStyle == DataGridViewCellBorderStyle.Single)
{
graphics.FillRectangle(brush2, rowBounds.Left + rowHeadersWidth - grid.HorizontalScrollingOffset + gridwidth - 1, rowBounds.Top, 1, rowBounds.Height);
}
if (!IsExpanded)
{
if (grid.CollapseIcon != null)
{
graphics.DrawImage(grid.ExpandIcon, rowBounds.Left + rowHeadersWidth - grid.HorizontalScrollingOffset + 4, rowBounds.Bottom - 18, 11, 11);
}
}
else
{
if (grid.CollapseIcon != null)
{
graphics.DrawImage(grid.CollapseIcon, rowBounds.Left + rowHeadersWidth - grid.HorizontalScrollingOffset + 4, rowBounds.Bottom - 18, 11, 11);
}
}
brush.Dispose();
brush2.Dispose();
}
base.Paint(graphics, clipBounds, rowBounds, rowIndex, rowState, isFirstDisplayedRow, isLastVisibleRow);
}
internal TreeDataGridViewRow(TreeDataGridView owner) : this()
{
Grid = owner;
IsExpanded = true;
}
