visual C++ Crect InflateRect Example

In this visual c++ CRect InflateRect example We build simple application that enlarge a rectangle and changing color
To initiate the move you press inside the small rectangle to get irregular enlargement or out side the rectangle to get regular inflation and multiple colors

To the Executable file click here InflatidREct_exe and the complete project theproject

Start Building the project

1- Start new MFC exe single document and name it like inflated_rect
2 - Add the following data members to your derived View class
CRect m_rect_red ,m_rect_blue ;
CBrush m_bar_red ,m_br_green ,m_brush_blue ,m_br_orange ;

and initiliza them in Cview constructor as follows

CInflated_rectangleView::CInflated_rectangleView(): m_rect_red(40,40,120,400),m_rect_blue(70,210,90,230),m_bar_red(RGB(99,0,0)),m_br_green(RGB(0,99,0)),m_brush_blue(RGB(0,0,99)),m_br_orange(RGB(0xCC,0x99,33))


3- Add the following messege handlers to your derived View class WM_RBUTTONDOWN ,WM_LBUTTONDOWN ,WM_TIMER

and edit the functions they generate as follows

void CInflated_rectangleView::OnLButtonDown(UINT nFlags, CPoint point)

m_rect_blue.InflateRect(2,5,1,12) ; // irregular inflation
SetTimer(1, 300,NULL) ; CView::OnLButtonDown(nFlags, point);

void CInflated_rectangleView::OnRButtonDown(UINT nFlags, CPoint point)
CView::OnRButtonDown(nFlags, point);

and finaly

void CInflated_rectangleView::OnTimer(UINT nIDEvent)
if( m_rect_blue.left>50)
m_rect_blue.InflateRect(4,1) ;

m_rect_blue.SetRect(70,210,90,230); // return to first siza



Finally edit t the ondraw function to as follows \

void CInflated_rectangleView::OnDraw(CDC* pDC)

pDC->TextOut(40,15," Press the left key to see the effect amd try to press inside the blue");

pDC->SelectObject( m_bar_red) ;
pDC->Rectangle( m_rect_red);
pDC->SelectObject(m_brush_blue) ;
pDC->SelectObject ( m_br_green);
if(m_rect_blue.top <=120)
pDC->SelectObject( m_br_orange);

pDC->Rectangle( m_rect_blue) ;


and then build the applications and enjoy it


Visual c++ IntersectRect example tutorial

In this visual c++ IntersectRect Example we will learn how to use the mfc intersection function

The intersected rectangle hatched in Red

to get the exefile click here and download the file and get the complete project and thinks of additions you can make

To start

1- Start a new project and let us name it IntersectRectangle

2- chose single document and deselect printing and print view no need for them

3- Add the following members to the view class


BOOL m_b_IsIntersected; // weather there is intersection or not

CRect m_Gray_Rectangle , m_Moving_Rectangle ,m_RectIntersection ;

// constant REct and moving and the rectangle of intersection

make your data members public to avoid using getters and setters

4-Initilize the values of the two rectangles in the constructor as follows



Add the following messege handler to the derived view class


and edit them as follows

start with Wm timer

void CIntersectrectangleView::OnTimer(UINT nIDEvent) {

if(m_Moving_Rectangle.right> 300) m_Moving_Rectangle.OffsetRect(-280,0) ;

m_Moving_Rectangle.OffsetRect(20,0);InvalidateRect(NULL,TRUE); CView::OnTimer(nIDEvent);}


void CIntersectrectangleView::OnRButtonDown(UINT nFlags, CPoint point) { KillTimer(1);

CView::OnRButtonDown(nFlags, point);}


void CIntersectrectangleView::OnLButtonDown(UINT nFlags, CPoint point) {

SetTimer(1, 450,NULL) ;

CView::OnLButtonDown(nFlags, point);



edit the ondraw member functions as follows

void CIntersectrectangleView::OnDraw(CDC* pDC){

pDC->TextOut(60,13,"Press the right button to start moving the black rectangle and the right to stop it and notice the intersection");





LPRECT lp_move = m_Moving_Rectangle.operator LPRECT() ;

// cast the moving rect to LPRECT

LPRECT lp_gray = m_Gray_Rectangle.operator LPRECT() ;

// and so as to the grayrect

m_b_IsIntersected = m_RectIntersection.IntersectRect( lp_move ,lp_gray);
// find whethere there is intersection and draw the intersection rect with hatchbrush
if( m_b_IsIntersected){

CBrush brushHatch(HS_DIAGCROSS, RGB(255, 90, 0));

pDC->SelectObject(brushHatch) ;

//I used getstockobject because it is easier to use


8- finally build the application and see how it works

Do not forget to use casting when using intersictRect it only accept arguments of type LPRECT

for more example see the rest of the blog

I hope that you enjoyed this tutorial