C#

sususan wrote:

Is the following grid layout possible with DataGridView in VB.net?

bool InsideMergedRowOfCells(e.ColumnIndex, e.RowIndex)
bool IsFirstOfMergedRowOfCells(e.ColumnIndex, e.RowIndex)
bool IsLastOfMergedRowOfCells(e.ColumnIndex, e.RowIndex)

private Rectangle accumulatedMerge = Rectangle.Empty;
private void grid_CellPainting(object sender, DataGridViewCellPaintingEventArgs e)
{
	// Default painting all other places than the merged cells
	if (!InsideMergedRowOfCells(e.ColumnIndex, e.RowIndex)) return;

	// Rows come x-first, then y. Utterly dependant on this we sample the
	// first cell in a set of merged cells and patiently wait for the last in the range
	if (IsFirstOfMergedRowOfCells(e.ColumnIndex, e.RowIndex))
	{
		accumulatedMerge = e.CellBounds;	// Save the first rectangle
		e.Handled = true;	// Tell caller not to call the cell's paint method override
		return;				// Return, i.e. wait for the last merged cell in the row
	}

	// If we are asked to paint the last of a horizontal range of merged cells, the we need to do some work
	if (IsLastOfMergedRowOfCells(e.ColumnIndex, e.RowIndex))
	{
		// First, calculate the entire rectangle of the merged cells
		accumulatedMerge.Width = (e.CellBounds.X + e.CellBounds.Width) - _accumulatedMerge.X;

		// Dirty hack to inject the CellBounds rectangle (which is read-only), by accessing the field directly through reflection
		FieldInfo cellBoundsField = e.GetType().GetField("cellBounds", BindingFlags.NonPublic | BindingFlags.Instance);
		cellBoundsField.SetValue(e, accumulatedMerge);

		// Call the standard paint with the hacked rectangle injected
		e.Paint(accumulatedMerge, DataGridViewPaintParts.All);
	}

	// Tell caller not to call the cell's paint method override
	e.Handled = true;
}