I am trying to draw on top of a CHtmlView. I tried overriding OnDraw() but I end up with either some Unhandled exception or nothing being drawn. Any tips or recommendations? Our documents contain a .bmp zipped inside the document and I am trying to display those images on to the CHtmlView.
Here's what I started on (reference: http://forums.codeguru.com/showthread.php?255739-Bitmaps-in-CHtmlView), just trying to use the pen to see if anything comes up:
void CMyHtmlView::OnDraw(CDC* pDC)
{
CDocument* pDoc = GetDocument();
ASSERT_VALID(pDoc);
IOleWindow* InterfacePtr;
HWND hwnd;
// long pointer to Idispatch interface
LPDISPATCH DispatchPtr;
// receives pointer to Idispatch
DispatchPtr = GetHtmlDocument();
// InterfacePtr now contains IOleWindow*
DispatchPtr->QueryInterface(IID_IOleWindow, (void**)&InterfacePtr);
// get the window handle
InterfacePtr->GetWindow(&hwnd);
// get dc from hwnd
CClientDC dc((CWnd*)hwnd);
CPen* Pen = new CPen;
Pen->CreatePen(PS_SOLID, 3 ,RGB(0, 0, 0));
dc.SelectObject(Pen);
dc.MoveTo(100,100);
dc.LineTo(300,300);
}
Setting the CClientDC may be part of the issue
Related
I need your help for a project at my job.
The main software, using 4D language, works as a MDI, it creates many windows included in the main window. The main issue is that we have a lot of windows and we need an easy way to switch from a window to another.
We decided to create a little c++ plugin which is a dll to resolve this issue.
This plugin will create a tab on the taskbar for each window opened like Windows Explorer. The creation and the deletion of tabs already works.
But the current problem is that no thumbnail is set on the Tab.
The parameter given is the ID of the window from the main software. The method called PA_GetHWND is the method given by 4D to obtain the handle of the window using the windowID.
I have already check where is the problem. The bitmap created from the window already exists and is good. For this test, i put the bitmap in the clipboard and paste it on Paint and the Bitmap was good.
Here is the code introducing the method to refresh the bitmap on the tab.
bool CManageTaskBar::UpdateWindow(long WindowID)
{
HRESULT res;
HDC hdcScreen;
HDC hdcWindow;
HDC hdcMemDC = NULL;
HBITMAP hbmScreen = NULL;
//Get the Handle from 4D
HWND nHandle = (HWND)(PA_GetHWND((PA_WindowRef)(WindowID)));
// Retrieve the handle to a display device context for the client
// area of the window.
hdcScreen = GetDC(NULL);
hdcWindow = GetDC(nHandle);
// Create a compatible DC which is used in a BitBlt from the window DC
hdcMemDC = CreateCompatibleDC(hdcWindow);
// Get the client area for size calculation
RECT rcClient;
GetClientRect(nHandle, &rcClient);
// Create a compatible bitmap from the Window DC
hbmScreen = CreateCompatibleBitmap(hdcWindow,rcClient.right - rcClient.left, rcClient.bottom - rcClient.top);
// Select the compatible bitmap into the compatible memory DC.
SelectObject(hdcMemDC, hbmScreen);
// Bit block transfer into our compatible memory DC.
if (!BitBlt(hdcMemDC,
0, 0,
rcClient.right - rcClient.left, rcClient.bottom - rcClient.top,
hdcWindow,
0, 0,
SRCCOPY))
{
MessageBox(nHandle, L"BitBlt has failed", L"Failed", MB_OK);
//goto done;
}
ITaskbarList3* ptbl = NULL;
HRESULT hr = CoCreateInstance(my_CLSID_TaskbarList, NULL, CLSCTX_ALL, my_IID_ITaskbarList3, (LPVOID*)&ptbl);
BOOL fForceIconic = TRUE;
BOOL fHasIconic = TRUE;
res = DwmSetWindowAttribute(nHandle, DWMWA_FORCE_ICONIC_REPRESENTATION, &fForceIconic, sizeof(fForceIconic));
res = DwmSetWindowAttribute(nHandle, DWMWA_HAS_ICONIC_BITMAP, &fHasIconic, sizeof(fHasIconic));
if (hbmScreen)
{
res = DwmSetIconicThumbnail(nHandle, hbmScreen,0);//DWM_SIT_DISPLAYFRAME);
}
DeleteObject(hbmScreen);
DeleteObject(hdcMemDC);
ReleaseDC(NULL, hdcScreen);
ReleaseDC(nHandle, hdcWindow);
return true;
}
The calls to DwmSetWindowAttribute return Invalid Handle. This handle works to get a bitmap but not to set an attribute.
And the call to DwmSetIconicThumbnail returns E_INVALIDARG maybe because the handle given is wrong.
Why cannot I set an attribute to this handle and why the call to set the thumbnail returns E_INVALIDARG ?
Thanks to everyone who will take care of my problem.
It's my first question, be friendly please :)
I use the following code to get the size of the bitmap bound with Windows MFC View window's client area DC:
void CView::OnDraw(CDC* )
{
CDC *pDc = GetDC();
BITMAP bmpHeader;
memset( &bmpHeader, 0, sizeof(BITMAP));
HGDIOBJ hbmp = GetCurrentObject(pDc->m_hDC, OBJ_BITMAP);
GetObject(hbmp,sizeof(BITMAP), &bmpHeader);
int bmpWidth = bmpHeader.bmWidth;
int bmpHeight = bmpHeader.bmHeight;
...
}
According to MSDN GetDC() gets the client area dc:
Retrieves a pointer to a common, class, or private device context for the client area depending on the class style specified for the CWnd
So I suppose the bmpWidth and bmpHeight should be the same size as client area rect. But it isn't. It appears to be the size of entire window including toolbar area and menu area. Am I doing something wrong here?
Use GetClientRect to find with and height of client area. This is the area which does not include the titlebar and borders. Instead of calling GetDC(), use the CDC* parameter which is already provided, or else use CClientDC dc(this) which has automatic cleanup. In this case drawing should be something like this:
void CMyView::OnDraw(CDC* dc)
{
CRect rc;
GetClientRect(&rc);
dc->FillSolidRect(rc, RGB(0, 0, 255));
}
Use Window Functions to get information about Windows.
Most Window functions have equivalent in MFC. For example,
In WinApi: GetClientRect(HWND hwnd, LPRECT rc);
In MFC: CWnd::GetClientRect(LPRECT rc);
I am trying to display a bitmap image using MFC application.
I am using a browse button to select file which is working properly. But when I try to load an image by double clicking on the file, the application is launched, but the image is not displayed.
Here is my code for browse button and function to open a double clicked image.
void COpenImageDlg::OnBnClickedButton1()
{
// TODO: Add your control notification handler code here
CString path;
CFileDialog dlg(TRUE);
int result=dlg.DoModal();
if(result==IDOK)
{
path=dlg.GetPathName();
UpdateData(FALSE);
}
HBITMAP hBmp = (HBITMAP)::LoadImage(NULL, path, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE|LR_CREATEDIBSECTION);
CBitmap bmp;
bmp.Attach(hBmp);
CClientDC dc(this);
CDC bmDC;
bmDC.CreateCompatibleDC(&dc);
CBitmap *pOldbmp = bmDC.SelectObject(&bmp);
BITMAP bi;
bmp.GetBitmap(&bi);
dc.BitBlt(0,0,bi.bmWidth,bi.bmHeight,&bmDC,0,0,SRCCOPY);
bmDC.SelectObject(pOldbmp);
}
void COpenImageDlg::OpenImage1(CString path)
{
//CString path;
CFileDialog dlg(TRUE);
int result=dlg.DoModal();
if(result==IDOK)
{
path=dlg.GetPathName();
UpdateData(FALSE);
}
HBITMAP hBmp = (HBITMAP)::LoadImage(NULL, path, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE|LR_CREATEDIBSECTION);
CBitmap bmp;
bmp.Attach(hBmp);
CClientDC dc(this);
CDC bmDC;
bmDC.CreateCompatibleDC(&dc);
CBitmap *pOldbmp = bmDC.SelectObject(&bmp);
BITMAP bi;
bmp.GetBitmap(&bi);
dc.BitBlt(0,0,bi.bmWidth,bi.bmHeight,&bmDC,0,0,SRCCOPY);
}
Init class :
`BOOL COpenImageApp::InitInstance()
{
// InitCommonControlsEx() is required on Windows XP if an application
// manifest specifies use of ComCtl32.dll version 6 or later to enable
// visual styles. Otherwise, any window creation will fail.
INITCOMMONCONTROLSEX InitCtrls;
InitCtrls.dwSize = sizeof(InitCtrls);
// Set this to include all the common control classes you want to use
// in your application.
InitCtrls.dwICC = ICC_WIN95_CLASSES;
InitCommonControlsEx(&InitCtrls);
CWinApp::InitInstance();
AfxEnableControlContainer();
// Create the shell manager, in case the dialog contains
// any shell tree view or shell list view controls.
CShellManager *pShellManager = new CShellManager;
// Standard initialization
// If you are not using these features and wish to reduce the size
// of your final executable, you should remove from the following
// the specific initialization routines you do not need
// Change the registry key under which our settings are stored
// TODO: You should modify this string to be something appropriate
// such as the name of your company or organization
SetRegistryKey(_T("Local AppWizard-Generated Applications"));
COpenImageDlg dlg;
m_pMainWnd = &dlg;
INT_PTR nResponse = dlg.DoModal();
char* buff;
char* command_line = GetCommandLine();
buff = strchr(command_line, ' ');
buff++;
buff = strchr(buff, ' ');
buff++;
buff = strchr(buff, ' ');
buff++;
if (buff != NULL)
{
HBITMAP hBmp = (HBITMAP)::LoadImage(NULL, "C:\Users\Raguvaran\Desktop\tiger.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE|LR_CREATEDIBSECTION);
CBitmap bmp;
bmp.Attach(hBmp);
dlg.RedrawWindow();
CClientDC dc(m_pMainWnd);
CDC bmDC;
bmDC.CreateCompatibleDC(&dc);
CBitmap *pOldbmp = bmDC.SelectObject(&bmp);
BITMAP bi;
bmp.GetBitmap(&bi);
dc.BitBlt(0,0,bi.bmWidth,bi.bmHeight,&bmDC,0,0,SRCCOPY);
}
//RedrawWindow(dlg, NULL, NULL, RDW_INVALIDATE);
//UpdateWindow(dlg);
if (nResponse == IDOK)
{
// TODO: Place code here to handle when the dialog is
// dismissed with OK
}
else if (nResponse == IDCANCEL)
{
// TODO: Place code here to handle when the dialog is
// dismissed with Cancel
}
// Delete the shell manager created above.
if (pShellManager != NULL)
{
delete pShellManager;
}
// Since the dialog has been closed, return FALSE so that we exit the
// application, rather than start the application's message pump.
return FALSE;
}`
I used the same code for browse button and it displays the image. But when I double click the file, the image is not displayed. Please tell me what I am doing wrong.
If you have associated your application with a particular file extension, it will be launched automatically when you double-click such a file (as you have said).
When this happens, your application is launched with the file name (actually the full path) supplied as a command line argument to your application.
In SDI MFC applications, this is handled automatically by the framework as long as you haven't overridden the default File/Open handling mechanism, but if you have a dialog-based application you will need to add code for this yourself.
Your dialog COpenImageDlg is created and displayed inside the call to DoModal before the command line has a chance to be processed. When the DoModal returns, the dialog is already destroyed, so there is no dialog for the code to draw upon.
I understand that when you double click the file to choose a image on file dialog, the image doesn't show. I just tried your code of function OnBnClickedButton1 and OpenImage1. And it turns out that the image is displayed when double click to choose a image. I use VS2010 on win7. I hope this will help you though i donot find the error of your code.
I found the answer to my question.
It was actually a very stupid mistake.
When I read the file address using Commandline, the address has single slash, whereas I need to pass the address using double slash.
Such a silly bug. Sorry to waste your time.
I'd like to create a CWnd based class that will introduce a control with transparent background.
There is no big deal for me to create a control and draw its content with transparent background as long as the content is static.
The problem is when I want to create a control with changing content. It's becaue I don't know how to erase content of control with parent's background (which in general case may not be just a solid color).
So the goal I want to achieve is to erase control before painting its conent as the control was never there (parent, and maybe other controls may appear), and than paint control in this place.
Roel answer is fine if you want to create a top-level window. If you need to crate a child window (which must be the case if you are creating a control) you cannot use WS_EX_LAYERED (I think this has changed from Windows 8 on).
The easy trick is to draw parent as the control backgroud. So in the OnEraseBkgnd you can add this code:
BOOL uiBarcodeButton::OnEraseBkgnd(CDC* pDC)
{
CRect rect;
GetClientRect(rect);
return afxGlobalData.DrawParentBackground( this, pDC, rect);
}
Not sure if afxGlobalData global variable is just for MFC 2008 Feature Pack. If you are using a previous version of MFCs then you can use the code from DrawParentBackground:
ASSERT_VALID(pDC);
ASSERT_VALID(pWnd);
BOOL bRes = FALSE;
CRgn rgn;
if (rectClip != NULL)
{
rgn.CreateRectRgnIndirect(rectClip);
pDC->SelectClipRgn(&rgn);
}
CWnd* pParent = pWnd->GetParent();
ASSERT_VALID(pParent);
// In Windows XP, we need to call DrawThemeParentBackground function to implement
// transparent controls
if (m_pfDrawThemeBackground != NULL)
{
bRes = (*m_pfDrawThemeBackground)(pWnd->GetSafeHwnd(), pDC->GetSafeHdc(), rectClip) == S_OK;
}
if (!bRes)
{
CPoint pt(0, 0);
pWnd->MapWindowPoints(pParent, &pt, 1);
pt = pDC->OffsetWindowOrg(pt.x, pt.y);
bRes = (BOOL) pParent->SendMessage(WM_ERASEBKGND, (WPARAM)pDC->m_hDC);
pDC->SetWindowOrg(pt.x, pt.y);
}
pDC->SelectClipRgn(NULL);
return bRes;
You use WS_EX_LAYERED and the UpdateLayeredWindow() API to draw your window. See http://msdn.microsoft.com/en-us/library/ms997507.aspx .
I used below code for my custom Static control:
BOOL MyStaticText::OnEraseBkgnd(CDC* pDC)
{
CRect rect;
GetClientRect(&rect);
pDC->SelectObject((HBRUSH)GetStockObject(NULL_BRUSH));
return pDC->PatBlt(0, 0, rect.Width(), rect.Height(), PATCOPY);
}
Has anyone implemented Lightbox style background dimming on a modal dialog box in a MFC/non .net app.
I think the procedure would have to be something like:
steps:
Get dialog parent HWND or CWnd*
Get the rect of the parent window and draw an overlay with a translucency over that window
allow the dialog to do it's modal draw routine, e.g DoModal()
Are there any existing libraries/frameworks to do this, or what's the best way to drop a translucent overlay in MFC?
edit Here's a mockup of what i'm trying to achieve if you don't know what 'lightbox style' means
Some App:
with a lightbox dialog box
Here's what I did* based on Brian's links
First create a dialog resource with the properties:
border FALSE
3D look FALSE
client edge FALSE
Popup style
static edge FALSE
Transparent TRUE
Title bar FALSE
and you should end up with a dialog window with no frame or anything, just a grey box.
override the Create function to look like this:
BOOL LightBoxDlg::Create(UINT nIDTemplate, CWnd* pParentWnd)
{
if(!CDialog::Create(nIDTemplate, pParentWnd))
return false;
RECT rect;
RECT size;
GetParent()->GetWindowRect(&rect);
size.top = 0;
size.left = 0;
size.right = rect.right - rect.left;
size.bottom = rect.bottom - rect.top;
SetWindowPos(m_pParentWnd,rect.left,rect.top,size.right,size.bottom,NULL);
HWND hWnd=m_hWnd;
SetWindowLong (hWnd , GWL_EXSTYLE ,GetWindowLong (hWnd , GWL_EXSTYLE ) | WS_EX_LAYERED ) ;
typedef DWORD (WINAPI *PSLWA)(HWND, DWORD, BYTE, DWORD);
PSLWA pSetLayeredWindowAttributes;
HMODULE hDLL = LoadLibrary (_T("user32"));
pSetLayeredWindowAttributes =
(PSLWA) GetProcAddress(hDLL,"SetLayeredWindowAttributes");
if (pSetLayeredWindowAttributes != NULL)
{
/*
* Second parameter RGB(255,255,255) sets the colorkey
* to white LWA_COLORKEY flag indicates that color key
* is valid LWA_ALPHA indicates that ALphablend parameter
* is valid - here 100 is used
*/
pSetLayeredWindowAttributes (hWnd,
RGB(255,255,255), 100, LWA_COLORKEY|LWA_ALPHA);
}
return true;
}
then create a small black bitmap in an image editor (say 48x48) and import it as a bitmap resource (in this example IDB_BITMAP1)
override the WM_ERASEBKGND message with:
BOOL LightBoxDlg::OnEraseBkgnd(CDC* pDC)
{
BOOL bRet = CDialog::OnEraseBkgnd(pDC);
RECT rect;
RECT size;
m_pParentWnd->GetWindowRect(&rect);
size.top = 0;
size.left = 0;
size.right = rect.right - rect.left;
size.bottom = rect.bottom - rect.top;
CBitmap cbmp;
cbmp.LoadBitmapW(IDB_BITMAP1);
BITMAP bmp;
cbmp.GetBitmap(&bmp);
CDC memDc;
memDc.CreateCompatibleDC(pDC);
memDc.SelectObject(&cbmp);
pDC->StretchBlt(0,0,size.right,size.bottom,&memDc,0,0,bmp.bmWidth,bmp.bmHeight,SRCCOPY);
return bRet;
}
Instantiate it in the DoModal of the desired dialog, Create it like a Modal Dialog i.e. on the stack(or heap if desired), call it's Create manually, show it then create your actual modal dialog over the top of it:
INT_PTR CAboutDlg::DoModal()
{
LightBoxDlg Dlg(m_pParentWnd);//make sure to pass in the parent of the new dialog
Dlg.Create(LightBoxDlg::IDD);
Dlg.ShowWindow(SW_SHOW);
BOOL ret = CDialog::DoModal();
Dlg.ShowWindow(SW_HIDE);
return ret;
}
and this results in something exactly like my mock up above
*there are still places for improvment, like doing it without making a dialog box to begin with and some other general tidyups.
I think you just need to create a window and set the transparency. There is an MFC CGlassDialog sample on CodeProject that might help you. There is also an article on how to do this with the Win32 APIs.