SendMessage in win32 project has different result - c++

Question

I have a win32 project that has 2 text windows(inputArea, outputArea) and 2 buttons(sendButton and ResetButton).
My problem is that when I press Reset I want to clear the text from both areas, and the inputArea gets cleared but the outputArea gets colored.
Here is the code I have tried:
case IDC_ResetButton:
{
SendMessage(hwndInputArea, WM_SETTEXT, NULL, NULL);
SendMessage(hwndOutputArea, WM_SETTEXT, NULL, NULL);
break;
}
my intial inputArea:
my initial outputArea:
And here is what happens to outputArea when I press Reset:
Also, I tried each line of code separately and they work, but when I put both of them I get this result of the outputArea and I can't find out why.
Thank you in advance.

Answer 1

I guess that is editcontrol.
There are three options of color for that.
・text color
・background color
・drawing brush
HBRUSH CXxxDlg::OnCtlColor( CDC* pDC, CWnd* pWnd, UINT nCtlColor ) {
HBRUSH hbr = CDialog::OnCtlColor(pDC, pWnd, nCtlColor);
pDC->SetTextColor(RGB(0,0,0));
pDC->SetBkColor(RGB(192,192,192));　// …(1)
HBRUSH hbrOrg = static_cast<HBRUSH>(GetStockObject(GRAY_BRUSH));　// …(2)
return hbrOrg;
}
(1)(2)… make the same color

Answer 2

try to get the handle of you edit control each time on your button case like this (Change IDC_EDIT1 and 2 to your edit control ID):
case IDC_ResetButton:
{
hwndInputArea = GetDlgItem(hwndDlg,IDC_EDIT1);
hwndOutputArea = GetDlgItem(hwndDlg,IDC_EDIT2);
SendMessage(hwndInputArea, WM_SETTEXT, 0, NULL);
SendMessage(hwndOutputArea, WM_SETTEXT, 0, NULL);
break;
}