... switch(p->m_Draw ) { case 0: pDC -& gt;MoveTo (p->m_Old ); pDC -& gt;LineTo (p->m_Cur ); break; case 1: pDC -& gt;Rectangle (p->m_Old.x,p->m_Old.y,p->m_Cur.x,p->m_Cur.y); ... %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Bài 7: IDC_STATIC_CHUCHAYIDC_CHECK1 chọn BN_CLICKED Viết trong BOOL CBai1_3Dlg::OnInitDialog() UpdateData (true); m_chuchay=" ;- DOC LAP - TU DO - HANH PHUC "; i =1; UpdateData ... pDC -& gt;Ellipse (p->m_Old.x,p->m_Old.y,p->m_Cur.x,p->m_Cur.y); break; } pDC -& gt;SelectObject (p); } //ve hinh moi****************************** CBrush* pBrush=pDC -& gt;SelectObject...