I have a MFC Application with Dialog Based. I created a GDI+ Object from resource by using this.
MyDlg.cpp:
BOOL CSetupDlg::OnInitDialog()
{
Gdiplus::GdiplusStartupInput gdiplusStartupInput;
Gdiplus::GdiplusStartup(&m_gdiplusToken, &gdiplusStartupInput, NULL);
...
}
void MyFunction():
CGdiPlusBitmapResource* pBitmap = new CGdiPlusBitmapResource;
if (pBitmap->Load(ID_SPL_LG))
{
CPaintDC dc(this);
Gdiplus::Graphics graphics(dc);
graphics.DrawImage(*pBitmap, 0, 0);
//It is loaded . I checked with messagebox and its in here.
}
Invalidate(); //Not sure if necessary.
Now, Form/Dialog shows nothing. No image inserted nor attached.
Now, i tried few things to add this image to the dialog but i am unable to do it.
What i tried is GDIObject.Create(), CStatic.Create() and PictureControl.Create()
All i want to do is insert this image to the dialog.
Any idea or showing path is appreciated.
You will need to override the OnPaint method that responds to the WM_PAINT message in your dialog. Normally you don't need to do this because the dialog doesn't need to paint anything, it just lets the controls that are contained on it paint themselves.
Move the code you show into the OnPaint handler.
Do not call the default OnPaint from your own handler.
Do not call Invalidate from within the OnPaint handler or you will get an infinite loop.
Related
We have a requirement to change the color of pushbutton/control. I have controls defined in resource file.
We have tried multiple ways
1)Using CMFCButton Object I got defination ambiguity errors
2)
Using CBUtton CDC* pdcWindow1 = m_Button.GetWindowDC(); CRect rect1; GetClientRect(&rect1); pdcWindow1->FillSolidRect(&rect1, (RGB(0, 0, 255)));
No effect on Button color no error as well.
Inputs which i have got so far : we have used ATLcontrols and to color Button we need MFC Functions, here ATL and MFC libs can't coexist they are causing ambiguity errors as both have same functional definitions.
Is it even possible to color ATL controls without MFC functions.?
only solution is --https://jeffpar.github.io/kbarchive/kb/173/Q173974/??
Look of standard Windows GDI buttons is customized according to Button Color Messages:
The system sends a WM_CTLCOLORBTN message to a button's parent window before drawing a button. This message contains a handle to the button's device context and a handle to the child window. The parent window can use these handles to change the button's text and background colors. However, only owner-drawn buttons respond to the parent window processing the message.
In ATL project, you would either handle this notification message in parent window class or use more sophisticated message forwarding (reflection) to reflect this message to button class.
Either way you don't really paint (FillSolidRect), you can just update colors in the message handler. And also pay attention that only owner-drawn buttons expose this functionality.
See also: Owner-drawn button, WM_CTLCOLORBTN and WM_DRAWITEM (clearing an HDC)
This is how I was able to achieve :
HINSTANCE hInstance = GetModuleHandle(NULL);
HANDLE hBitmap = LoadImage(hInstance, MAKEINTRESOURCE(IDB_CURCANCEL_LOGO), IMAGE_BITMAP, 0, 0, LR_DEFAULTCOLOR);
HANDLE hBitmap1 = LoadImage(hInstance, MAKEINTRESOURCE(IDB_CURLOGIN_LOGO), IMAGE_BITMAP, 0, 0, LR_DEFAULTCOLOR);
const HWND hOriginalLoginButton = GetDlgItem(IDOK);
const HWND hOriginalCancelButton = GetDlgItem(IDCANCEL);
SendMessage(hOriginalLoginButton, BM_SETIMAGE, (WPARAM)IMAGE_BITMAP, (LPARAM)hBitmap1);
SendMessage(hOriginalCancelButton, BM_SETIMAGE, (WPARAM)IMAGE_BITMAP, (LPARAM)hBitmap);
Now i am trying to make corners rounded.
I'm currently trying to draw something outside OnPaint function. I know there are many duplicate questions on the internet, however, I failed to get any of them to work. This is entirely because of my lack of understanding of MFC.
What works inside OnPaint:
CDC* pDC = GetDC();
HDC hDC = pDC->GetSafeHdc();
CRect lDisplayRect;
GetDlgItem(IDC_DISPLAYPOS)->GetClientRect(&lDisplayRect);
GetDlgItem(IDC_DISPLAYPOS)->ClientToScreen(&lDisplayRect);
ScreenToClient(&lDisplayRect);
pDC->FillSolidRect(&lDisplayRect, GetSysColor(COLOR_3DDKSHADOW));
pDC->TextOutW(300, 300, TEXT("test"));
It fills the area of the button control I have with a defined colour.
And it prints out the "test" string without any issue.
But it won't work outside OnPaint.
I've seen numerous suggestions such as using CmemDC,CPaintDC, etc
But none of them worked outside OnPaint.
For example,
CClientDC dc(this);
dc.rectangle( ....);
does not work.
Please note that this is a temporary test code and what I am eventually trying to do is draw incoming frames from a frame grabber within my display thread (a separate thread from the main UI thread) on the DisplayPos area and my dlg object(the dialog) owns an instance of the DisplayThread class. And I'm passing HWND and displayrect upon creating the member mDisplayThread so I can draw stuff within the display thread and that's the reason why I need to be able to draw to DC outside OnPaint (DisplayThread class does not have OnPaint or inherit any class that has it).
I'm in dire need of help...Please help!
Added: I have overridden PreTranslateMessage(MSG* pMsg) and made it return without calling the default function just in case WM_ERASE msg is erasing everything, but this approach didn't work either.
For example:
void CMFCApplicationDlg::OnLButtonDown(UINT nFlags, CPoint point)
{
// TODO: Add your message handler code here and/or call default
HDC hdc = ::GetDC(m_hWnd);
Ellipse(hdc, point.x - 10, point.y - 10, point.x + 10, point.y + 10);
::ReleaseDC(m_hWnd, hdc);
CDialogEx::OnLButtonDown(nFlags, point);
}
Two important suggestions:
Do not draw outside of OnPaint. The content may be erased or painted over at the direction of OS.
Do not draw on the dialog surface. First, it is not designed for that. It may be affected by other controls or by theming, skinning, etc. Just create a window with your own window procedure, so you are in control.
I would store the information needed for drawing in you frame grabber, and cause an immediate window painting by calling RedrawWindow
I have a dialog based application written in c++ and MFC. The dialog has a CStatic picture control. I am drawing a BITMAP in the OnPaint() function of the PictureCtrl. The relevant code is as follows:
void PictureCtrl::OnPaint()
{
CDC* pDC = this->GetDC();
pDC->SelectStockObject(PS_SOLID);
pDC->Rectangle(CRect(0, 0, 400, 400));
ReleaseDC(pDC);
CStatic::OnPaint();
}
When the application runs, the rectangle is drawn right on the top-left corner of the dialog, and not the picture control.
Secondly, if I minimize and maximize the dialog window, the image shows up, but the rectangle doesn't.
However, if I hover the mouse in the windows taskbar and a tooltip appears on the icon of the dialog application, the rectangle shows up.
I want to show the rectangle over the image no matter what the user does to the window (minimize, maximize, move, etc.).
CStatic::OnPaint handles BeginPaint/EndPaint (main WinAPI functions) in response to WM_PAINT message. Therefore it should be called first. Moreover, you can use CClientDC which has automatic clean up:
void PictureCtrl::OnPaint()
{
CStatic::OnPaint();
CClientDC dc(this); //<- uses GetDC
dc.SelectStockObject(BLACK_PEN);
dc.Rectangle(CRect(0, 0, 400, 400));
} //<- ReleaseDC is automatically called
Better yet, use CPaintDC directly in response to WM_PAINT message:
void PictureCtrl::OnPaint()
{
CPaintDC dc(this); //<- calls `BeginPaint`
dc.SelectStockObject(BLACK_PEN);
dc.Rectangle(CRect(0, 0, 400, 400));
} //<- EndPaint is automatically called
Unrelated, use BLACK_PEN as parameter for SelectStockObject. Use PS_SOLID as parameter for CPen:
CPen pen(PS_SOLID, 1, RGB(0,0,0));
I understand that the onDraw() function is virtual void which is called automatically via OnPaint(), which is itself triggered by the WM_PAINT message.
My declaration goes something like this:
myDialog.cpp
void myDialog::OnDraw(CDC* dc)
{
CCustomMemDC pDC(dc);
CExampleDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);
}
myDialog.h
afx_msg void OnDraw(CDC* dc);
and in my OnPaint()
CDialog::OnPaint();
However I could not get OnDraw to be triggered at all... Could anyone enlighten if this method is correct?
Thanks!
A dialog has no OnDraw. This is a virtual function in views to allow printing and drawing to a screen.
In a dialog just use OnPaint. There isno redirection to a virtual OnDraw function in a dialog.
It is not correct. As others have pointed out, OnDraw() is a virtual method of CView and not CDialog. Therefore, your OnDraw() method will never be called.
I don't know why your dialog would have a flicker problem that you would need to mitigate it. If you have a custom control on the dialog that is causing flicker, then you probably need to fix the drawing code in it and possibly add WS_CLIPCHILDREN as a Window Style to your dialog. That will make sure that the background of the custom control is not erased when the dialog executes its WM_ERASEBKGND message.
It makes no sense to override the WM_PAINT of the dialog unless you are really planning to do custom drawing on it. Unless you have a very good reason, don't do it.
If you choose to ignore the advice then add an ON_WM_PAINT() to your message handler to the dialog, and then draw the dialog yourself:
void myDialog::OnPaint()
{
CPaintDC dc(this);
CCustomMemDC pDC(&dc);
// do your specialized code knowing you are responsible for drawing the whole dialog
}
If you really want to use your OnDraw() method, then you could also write OnPaint() like this:
void myDialog::OnPaint()
{
CPaintDC dc(this);
OnDraw(&dc);
}
But, the first thing I would do in your situation is try adding the style WS_CLIPCHILDREN to your dialog style.
I'd like to be able to do some drawing to the right of the menu bar, in the nonclient area of a window.
Is this possible, using C++ / MFC?
Charlie hit on the answer with WM_NCPAINT. If you're using MFC, the code would look something like this:
// in the message map
ON_WM_NCPAINT()
// ...
void CMainFrame::OnNcPaint()
{
// still want the menu to be drawn, so trigger default handler first
Default();
// get menu bar bounds
MENUBARINFO menuInfo = {sizeof(MENUBARINFO)};
if ( GetMenuBarInfo(OBJID_MENU, 0, &menuInfo) )
{
CRect windowBounds;
GetWindowRect(&windowBounds);
CRect menuBounds(menuInfo.rcBar);
menuBounds.OffsetRect(-windowBounds.TopLeft());
// horrible, horrible icon-drawing code. Don't use this. Seriously.
CWindowDC dc(this);
HICON appIcon = (HICON)::LoadImage(AfxGetResourceHandle(), MAKEINTRESOURCE(IDR_MAINFRAME), IMAGE_ICON, 16, 16, LR_DEFAULTCOLOR);
::DrawIconEx(dc, menuBounds.right-18, menuBounds.top+2, appIcon, 0,0, 0, NULL, DI_NORMAL);
::DestroyIcon(appIcon);
}
}
In order to draw in the non-client area, you need to get the "window" DC (rather than "client" DC), and draw in the "window" DC.
You should try handling WM_NCPAINT. This is similar to a normal WM_PAINT message, but deals with the entire window, rather than just the client area. The MSDN documents on WM_NCPAINT provide the following sample code:
case WM_NCPAINT:
{
HDC hdc;
hdc = GetDCEx(hwnd, (HRGN)wParam, DCX_WINDOW|DCX_INTERSECTRGN);
// Paint into this DC
ReleaseDC(hwnd, hdc);
}
This code is intended to be used in the message loop of your applicaton, which is canonically organized using a large 'switch' statement.
As noted in the MFC example from Shog, make sure to call the default version, which in this example would mean a call to DefWindowProc.
If you just want something in the menu bar, maybe it is easier/cleaner to add it as a right-aligned menu item. This way it'll also work with different Windows themes, etc.