Background of the control is becoming dark on minimising and maximizing the window

Question

Control background is getting changed after minimizing and maximizing the window. I want the background to be same and transparent.

This is an ActiveX control. which can be used in multiple projects. CEdit is the base class for this control on which I have added some extra feature. I tried setting Bkmode in OnCtlColor and OnCtlColor but it is not working out.

Could you provide more details ? What kind of control it is there ? Doesn't look as standard. — Flaviu_, Dec 14 '16 at 09:21
And, please provide any appropriate code that might help illustrate your problem. — rrirower, Dec 14 '16 at 14:44
I have edited the question. please let me know if you need more information. — Anoop Kumar, Dec 15 '16 at 04:40

score 0 · Answer 1 · answered Dec 22 '16 at 05:01

0

I resolved this by fetching the background color and filling the rec of the control

BOOL CComboBoxCtrl::OnEraseBkgnd(CDC* pDC) 
{
COleControl::OnEraseBkgnd(pDC);
RECT rc,rc1;
GetClientRect(&rc);
// Get the color from the parent window
COLORREF crBkgnd = COleControl::AmbientBackColor();

//Fill the rect to overcome the black background issue
pDC->FillSolidRect(&rc,crBkgnd);

if(inputbox != NULL)
    inputbox->Invalidate(TRUE);
return S_OK;

}

answered Dec 22 '16 at 05:01

Anoop Kumar

137
10

`S_OK` is a COM `HRESULT` (that evaluates to 0). Since you did erase the background, [OnEraseBkgnd](https://msdn.microsoft.com/en-us/library/a0a52fkz.aspx) should return a non-zero value. Besides, you aren't using `rc1`. Why is it there? And why do you ignore compiler warnings? – IInspectable Dec 22 '16 at 18:58

Background of the control is becoming dark on minimising and maximizing the window

1 Answers1