For the position for the context menu, y found the problem that I needed a it to be relative to the DataGridView, and the event I needed to use gives the poistion relative to the cell clicked. I haven't found a better solution so I implemented this function in the commons class, so I call it from wherever I need.
It's quite tested and works well. I Hope you find it useful.
/// <summary>
/// When DataGridView_CellMouseClick ocurs, it gives the position relative to the cell clicked, but for context menus you need the position relative to the DataGridView
/// </summary>
/// <param name="dgv">DataGridView that produces the event</param>
/// <param name="e">Event arguments produced</param>
/// <returns>The Location of the click, relative to the DataGridView</returns>
public static Point PositionRelativeToDataGridViewFromDataGridViewCellMouseEventArgs(DataGridView dgv, DataGridViewCellMouseEventArgs e)
{
int x = e.X;
int y = e.Y;
if (dgv.RowHeadersVisible)
x += dgv.RowHeadersWidth;
if (dgv.ColumnHeadersVisible)
y += dgv.ColumnHeadersHeight;
for (int j = 0; j < e.ColumnIndex; j++)
if (dgv.Columns[j].Visible)
x += dgv.Columns[j].Width;
for (int i = 0; i < e.RowIndex; i++)
if (dgv.Rows[i].Visible)
y += dgv.Rows[i].Height;
return new Point(x, y);
}