Now I have a CImage img, and I wanted to copy the bitmap to the OLE clipboard.
What I did is the following
HBITMAP hImage = img.Detach();
CBitmap *pBitmap = CBitmap::FromHandle(hImage);
BITMAP bm;
pBitmap->GetObject(sizeof(bm), &bm);
HBITMAP hImage = Detach();
// the bitmap src
CBitmap *pBitmap = CBitmap::FromHandle(hImage);
BITMAP bm;
pBitmap->GetObject(sizeof(bm), &bm);
// the copy (dest)
CBitmap bitmap;
bitmap.CreateBitmapIndirect(&bm);
// create mem dc and select src and dest bitmaps
CDC dcMemSrc, dcMemDest;
dcMemSrc.CreateCompatibleDC(NULL);
CBitmap* pOldBitmapSrc = dcMemSrc.SelectObject(pBitmap);
dcMemDest.CreateCompatibleDC(NULL);
CBitmap* pOldBitmapDest = dcMemDest.SelectObject(&bitmap);
// bit-blt
dcMemDest.BitBlt(0, 0, bm.bmWidth, bm.bmHeight, &dcMemSrc,
0, 0, SRCCOPY);
HBITMAP hBitmap = (HBITMAP)bitmap.Detach();
// restore mem dc
dcMemDest.SelectObject(pOldBitmapDest);
dcMemSrc.SelectObject(pOldBitmapSrc);
// Place the copy on the clipboard.
AfxOleInit();
CoInitialize(NULL);
COleDataSource* pods = new COleDataSource;
pods->CacheGlobalData(CF_BITMAP, hBitmap);
pods->SetClipboard();
CoUninitialize();
I tested the program, it just doesn't work, I tried to CTRL+V to the Windows Paint program, but it complained the data cannot be pasted in it. If I use the Legacy Clipboard(just replace the last 6 lines with ::OpenClipboard(hWnd), ::EmptyClipboard(), ::SetClipboardData(CF_BITMAP, hBitmap), ::CloseClipboard() ), it works fine. I have no experience working with COM and OLE, can anyone help? Many thanks.
Related
I have some difficulties trying to copy a HBITMAP to the clipboard. My HBITMAP is created from a COLORREF array and I am able to display it correctly. Here is how it is created:
COLORREF* colors = new COLORREF[imageSize[0] * imageSize[1]];
for (int i = 0; i < imageSize[1]; i++) {
for (int j = 0; j < imageSize[0]; j++) {
colors[imageSize[0] * i + j] = RGB(/* ... */);
}
}
// Create bitmap
HBITMAP hBitmap = CreateBitmap(imageSize[0], imageSize[1], 1, 32, (void*)colors);
delete[] colors;
In order to copy my bitmap to the clipboard, I use this small piece of code:
OpenClipboard(hWnd);
EmptyClipboard();
SetClipboardData(CF_BITMAP, hBitmap);
CloseClipboard();
When I execute my app, I am able to copy the bitmap and paste it somewhere, for example in MS Paint. But if I try to copy it a second time, the clipboard content can't be pasted anymore unless the first piece of code above is executed again.
In the MSDN documentation, it is said that
If SetClipboardData succeeds, the system owns the object identified by the hMem parameter.
I don't understand exactly what this means, but I guess it is the source of my problem. I found an example of a function which does what I want here, but it does not seem to use the same kind of variables. Another example, using strings this time, can be found here.
I am not too sure how to translate this last example to my case. Could you point me in the right direction?
A comment that was deleted helped me find the answer. I actually have to copy my HBITMAP to another HBITMAP before calling SetClipboardData. This way, the copied bitmap can be sent to the clipboard, and the original bitmap is kept for later.
To copy the bitmap, I used the code that can be found in Copying a Bitmap to another Bitmap. In my code, it looks like this:
// Create a new bitmap
HBITMAP hBitmap_copy = CreateBitmap(imageSize[0], imageSize[1], 1, 32, NULL);
// Copy the source bitmap to the new one
HDC srcDC = CreateCompatibleDC(GetDC(NULL));
HDC newDC = CreateCompatibleDC(GetDC(NULL));
HBITMAP srcBitmap = (HBITMAP)SelectObject(srcDC, hBitmap);
HBITMAP newBitmap = (HBITMAP)SelectObject(newDC, hBitmap_copy);
BitBlt(newDC, 0, 0, imageSize[0], imageSize[1], srcDC, 0, 0, SRCCOPY);
SelectObject(srcDC, srcBitmap);
SelectObject(newDC, newBitmap);
DeleteDC(srcDC);
DeleteDC(newDC);
// hBitmap_copy can now be copied to the clipboard
OpenClipboard(hWnd);
EmptyClipboard();
SetClipboardData(CF_BITMAP, hBitmap_copy);
CloseClipboard();
I can now copy the displayed bitmap as many times as I want!
// You can't pass hBitmap to SetClipboardData directly
OpenClipboard(NULL)
HBITMAP hBitmap = getBit(); // From somewhere
DIBSECTION ds;
::GetObject(hBitmap, sizeof(DIBSECTION), &ds);
//make sure compression is BI_RGB
ds.dsBmih.biCompression = BI_RGB;
HDC hdc = ::GetDC(NULL);
HBITMAP hbitmap_ddb = ::CreateDIBitmap(
hdc, &ds.dsBmih, CBM_INIT, ds.dsBm.bmBits, (BITMAPINFO*)&ds.dsBmih, DIB_RGB_COLORS);
::ReleaseDC(NULL, hdc);
EmptyClipboard();
SetClipboardData(CF_BITMAP, hbitmap_ddb);
CloseClipboard();
Working in mingw, having a terrible time creating a color DC in memory. For instance, in the following code snippet, as written, "foo_scratch.bmp" is a monochrome version of the
image (from an EMR_STRETCHDIBITS record). If instead aDC is omitted and srcDC uses the CreateDC directly, then that file has a color image.
Gdiplus::Bitmap *pbmp = NULL;
BITMAPINFO *pbitmapinfo = (BITMAPINFO *)((char *)lpEMFR + pEmr->offBmiSrc);
void *pBitsInMem = (char *)lpEMFR + pEmr->offBitsSrc;
HBITMAP hbmsrc;
HDC aDC = CreateDC("DISPLAY", "", NULL, NULL);
HDC srcDC = CreateCompatibleDC(aDC);
hbmsrc = CreateDIBitmap(
srcDC,
&(pbitmapinfo->bmiHeader),
CBM_INIT,
pBitsInMem,
pbitmapinfo,
DIB_RGB_COLORS);
if(hbmsrc){
CLSID pngClsid;
GetEncoderClsid(L"image/bmp", &pngClsid);
pbmp = Gdiplus::Bitmap::FromHBITMAP(hbmsrc,NULL);
pbmp->Save(L"C:\\Temp\\foo_scratch.bmp",&pngClsid, NULL);
This all comes to a head later when two images (hbmdst, hbmsrc) need to be put together with a bitblt operation. At present the best I have managed is monochrome. At worst the image is solid black. In this snippet the ROP has been hard coded to SRCCOPY, and I still have not succeeded in just copying the image from one HBITMAP to another. Very frustrating!
HDC dstDC = CreateCompatibleDC(aDC);
HBITMAP hbmdOld = (HBITMAP) SelectObject(dstDC, hbmdst);
HBITMAP hbmsOld = (HBITMAP) SelectObject(srcDC, hbmsrc);
GetObject(hbmsrc, sizeof(bm), &bm);
BitBlt(dstDC, 0, 0, bm.bmWidth, bm.bmHeight, srcDC, 0, 0, SRCCOPY);
SelectObject(srcDC, hbmsOld);
SelectObject(dstDC, hbmdOld);
(void) DeleteDC(dstDC);
pbmp = Gdiplus::Bitmap::FromHBITMAP(hbmdst,NULL);
pbmp->Save(L"C:\\Temp\\scratch.bmp",&pngClsid, NULL);
What am I doing wrong?
Thanks
Figured it out - wherever a bitmap is created have to use the DC directly associated with the display (or other device), not the "compatible" DC derived from the first DC.
How to convert HICON to HBITMAP in VC++?
I know this is an FAQ but all the solutions I've found on Google don't work. What I need is a function which takes a parameter HICON and returns HBITMAP.
Greatest if possible to make conversion to 32-bit bitmap even the icon is 24-bit, 16-bit or 8-bit.
This is the code, I don't know where it goes wrong:
HBITMAP icon_to_bitmap(HICON Icon_Handle) {
HDC Screen_Handle = GetDC(NULL);
HDC Device_Handle = CreateCompatibleDC(Screen_Handle);
HBITMAP Bitmap_Handle =
CreateCompatibleBitmap(Device_Handle,GetSystemMetrics(SM_CXICON),
GetSystemMetrics(SM_CYICON));
HBITMAP Old_Bitmap = (HBITMAP)SelectObject(Device_Handle,Bitmap_Handle);
DrawIcon(Device_Handle, 0,0, Icon_Handle);
SelectObject(Device_Handle,Old_Bitmap);
DeleteDC(Device_Handle);
ReleaseDC(NULL,Screen_Handle);
return Bitmap_Handle;
}
this code do it:
HICON hIcon = (HICON)LoadImage(instance, MAKEINTRESOURCEW(IDI_ICON), IMAGE_ICON, width, height, 0);
ICONINFO iconinfo;
GetIconInfo(hIcon, &iconinfo);
HBITMAP hBitmap = iconinfo.hbmColor;
and this is the code in the *.rc file:
IDI_ICON ICON "example.ico"
and this is the code in the *.h file:
#define IDI_ICON 4000
HDC hDC = GetDC(NULL);
HDC hMemDC = CreateCompatibleDC(hDC);
HBITMAP hMemBmp = CreateCompatibleBitmap(hDC, x, y);
HBITMAP hResultBmp = NULL;
HGDIOBJ hOrgBMP = SelectObject(hMemDC, hMemBmp);
DrawIconEx(hMemDC, 0, 0, hIcon, x, y, 0, NULL, DI_NORMAL);
hResultBmp = hMemBmp;
hMemBmp = NULL;
SelectObject(hMemDC, hOrgBMP);
DeleteDC(hMemDC);
ReleaseDC(NULL, hDC);
DestroyIcon(hIcon);
return hResultBmp;
I don't have code readily available to share, but I think this is pretty easy. You have to create the HBITMAP, create a device context, select the bitmap into the DC (this will make the bitmap the drawing area for this DC). Finally call the DrawIcon() function to draw your icon on this DC. After that detach the bitmap from the DC and destroy the DC. Your bitmap now should be ready to go.
Update after looking at your code:
I believe the problem is in the createCompatibleBitmap call. You are asking for a bitmap compatible with the memory DC, but memory DCs start with a 1 bit/pixel bitmap selected into them. Try asking for a bitmap compatible with the screen DC instead.
Update 2: you may want to look at this question as it seems related to your problem.
I found this(similar code works for me - 32x32 icons with or without alpha data):
used CopyImage (msdn link)
HICON hICON = /*your code here*/
HBITMAP hBITMAPcopy;
ICONINFOEX IconInfo;
BITMAP BM_32_bit_color;
BITMAP BM_1_bit_mask;
// 1. From HICON to HBITMAP for color and mask separately
//.cbSize required
//memset((void*)&IconInfo, 0, sizeof(ICONINFOEX));
IconInfo.cbSize = sizeof(ICONINFOEX);
GetIconInfoEx( hICON , &IconInfo);
//HBITMAP IconInfo.hbmColor is 32bit per pxl, however alpha bytes can be zeroed or can be not.
//HBITMAP IconInfo.hbmMask is 1bit per pxl
// 2. From HBITMAP to BITMAP for color
// (HBITMAP without raw data -> HBITMAP with raw data)
// LR_CREATEDIBSECTION - DIB section will be created,
// so .bmBits pointer will not be null
hBITMAPcopy = (HBITMAP)CopyImage(IconInfo.hbmColor, IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION);
// (HBITMAP to BITMAP)
GetObject(hBITMAPcopy, sizeof(BITMAP), &BM_32_bit_color);
//Now: BM_32_bit_color.bmBits pointing to BGRA data.(.bmWidth * .bmHeight * (.bmBitsPixel/8))
// 3. From HBITMAP to BITMAP for mask
hBITMAPcopy = (HBITMAP)CopyImage(IconInfo.hbmMask, IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION);
GetObject(hBITMAPcopy, sizeof(BITMAP), &BM_1_bit_mask);
//Now: BM_1_bit_mask.bmBits pointing to mask data (.bmWidth * .bmHeight Bits!)
BM_32_bit_color bitmap may be have Alpha *channel*(each 4th byte) already set! So - check for it before u add mask bit to color data.
I'm trying to write a class to wrap bitmap functionality in my program.
One useful feature would be to copy a bitmap from another bitmap handle. I'm a bit stuck:
void operator=( MyBitmapType & bmp )
{
HDC dcMem;
HDC dcSource;
if( m_hBitmap != bmp.Handle() )
{
if( m_hBitmap )
this->DisposeOf();
// copy the bitmap header from the source bitmap
GetObject( bmp.Handle(), sizeof(BITMAP), (LPVOID)&m_bmpHeader );
// Create a compatible bitmap
dcMem = CreateCompatibleDC( NULL );
m_hBitmap = CreateCompatibleBitmap( dcMem, m_bmpHeader.bmWidth, m_bmpHeader.bmHeight );
// copy bitmap data
BitBlt( dcMem, 0, 0, bmp.Header().bmWidth, bmp.Header().bmHeight, dcSource, 0, 0, SRCCOPY );
}
}
This code is missing one thing: How can I get an HDC to the source bitmap if all I have of the source bitmap is a handle (e.g. an HBITMAP?)
You can see in the code above, I've used "dcSource" in the BitBlt() call. But I don't know how to get this dcSource from the source bitmap's handle (bmp.Handle() returns the source bitmaps handle)
You can't -- the source bitmap may not be selected into a DC at all, and even if it is you have no way to find out what DC.
To do your copy, you probably want to use something like:
dcSrc = CreateCompatibleDC(NULL);
SelectObject(dcSrc, bmp);
Then you can blit from the source to destination DC.
Worked for me:
// hBmp is a HBITMAP
HBITMAP hBmpCopy= (HBITMAP) CopyImage(hBmp, IMAGE_BITMAP, 0, 0, LR_DEFAULTSIZE);
I want to create a crop function in an existing engine. This is what I already have:
bool Bitmap::Crop(RECT cropArea)
{
BITMAP bm;
GetObject(m_Handle, sizeof(bm), &bm);
HDC hSrc = CreateCompatibleDC(NULL);
SelectObject(hSrc, m_Handle);
HDC hNew = CreateCompatibleDC(NULL);
HBITMAP hBmp = CreateCompatibleBitmap(hNew, bm.bmWidth, bm.bmHeight);
HBITMAP hOld = (HBITMAP)SelectObject(hNew, hBmp);
BitBlt(hNew, 0, 0, bm.bmWidth, bm.bmHeight, hSrc, 0, 0, SRCCOPY);
SelectObject(hNew, hOld);
DeleteDC(hSrc);
DeleteDC(hNew);
DeleteObject(m_Handle);
m_Handle = hBmp;
}
I want it to just copy the whole image to a new HBITMAP and replace the old with it. So I know that it works. After that it is just playing with the BitBlt parameters.
m_Handle is a HBITMAP of the class Bitmap.
The result of this code is just a black screen.
Thanks for helping me.
The function works perfectly now.
bool Bitmap::Crop(RECT cropArea)
{
HDC hSrc = CreateCompatibleDC(NULL);
SelectObject(hSrc, m_Handle);
HDC hNew = CreateCompatibleDC(hSrc);
HBITMAP hBmp = CreateCompatibleBitmap(hSrc, cropArea.right - cropArea.left, cropArea.bottom - cropArea.top);
HBITMAP hOld = (HBITMAP)SelectObject(hNew, hBmp);
bool retVal = (BitBlt(hNew, 0, 0, cropArea.right - cropArea.left, cropArea.bottom - cropArea.top, hSrc, cropArea.left, cropArea.top, SRCCOPY))?true:false;
SelectObject(hNew, hOld);
DeleteDC(hSrc);
DeleteDC(hNew);
DeleteObject(m_Handle);
m_Handle = hBmp;
return retVal;
}
Never create a compatible bitmap from a 'fresh' memory DC.
Unless that is you WANT to create a 1bpp bitmap - the default bitmap selected in a new memory DC is a 1x1 1bpp bitmap - so any compatible bitmap you create will match that.
Which does tend to result in all black output.
Your color bitmap in in hSrc, so use that dc to make the new bitmap.
Two small changes:
HBITMAP hBmp = CreateCompatibleBitmap(hNew, cropArea.right - cropArea.left, cropArea.bottom - cropArea.top);
BitBlt(hNew, 0, 0, cropArea.right - cropArea.left, cropArea.bottom - cropArea.top, hSrc, cropArea.left, cropArea.top, SRCCOPY);
You might want a little more checking to make sure the requested area falls within the size of the original bitmap.