Il semblerait qu'il y ait eu un bug donc je reposte la solution:
using System;
using System.Drawing;
using System.Windows.Forms;
privatevoidDG_MouseUp(object sender, MouseEventArgs e)
{
Point p =newPoint(e.X, e.Y);
DataGrid.HitTestInfo HTI = DG.HitTest(p);
if(HTI.Type == DataGrid.HitTestType.Cell)
{
DG.CurrentCell =newDataGridCell(HTI.Row, HTI.Column);
DG.Select(HTI.Row);
}
}