Line Drawing

[maverick786us]

I want to draw vertical and horizontal straight lines in WM_PAINT, How can I do it useing CDC?

[olivthill2]

CDC is for MFC if I am not wrong, and WM_PAINT is for programs that don't use MFC, if I am not wrong.

Here is a solution, not for MFC:

int paint_line(HWND hwnd, HDC hdc, int x0, int y0, int x9, int y9, int thickness, COLORREF rgb)
{
   HBRUSH hbr; HPEN hpen, hpen_sav;

   // int rop2_sav;
   // rop2_sav = SetROP2(hdc, R2_NOTXORPEN);

   hpen = CreatePen(PS_SOLID, thickness, rgb);
   hpen_sav = (HPEN) SelectObject(hdc, hpen);
   hbr = (HBRUSH)SelectObject(hdc, GetStockObject(NULL_BRUSH));

   MoveToEx(hdc, x0, y0, NULL);
   LineTo(hdc, x9, y9);
   DeleteObject(SelectObject(hdc, hbr));
   SelectObject(hdc, hpen_sav);
   DeleteObject(hpen);

   return 0;
}

[maverick786us]

Sorry I ean OnDraw. The way you can draw Rectangle and Ellipse, I want to draw lines

[joe_stoll]

MoveTo(x,y) moves the pen to position and LineTo(x,y) draws the line from MoveTo position to LineTo position

[joe_stoll]

this code draws grey lines,horizontal and vertical in center of screen

OnDraw()
{ 
       CRect rect;
	GetClientRect(rect);
	CPen penGrey;  // Construct it, then initialize
		if( penGrey.CreatePen( PS_SOLID, 0, RGB(200,200,200) ) )
		{
			// Select it into the device context
			// Save the old pen at the same time
			CPen* pOldPen = pDC->SelectObject( &penGrey );

			// Draw with the pen
			//draws axis
			pDC->MoveTo(rect.right/2,rect.top);
			pDC->LineTo(rect.right/2,rect.bottom);
			pDC->MoveTo(rect.right,rect.bottom/2);	
			pDC->LineTo(rect.left,rect.bottom/2);

			// Restore the old pen to the device context
			pDC->SelectObject( pOldPen );
		}
		else
		{
			MessageBox("Resources are running low\nPlease close one or more                     applications");		
		}
}

[Skizmo]

MSDN knows everything about the CDC object.