I am working on one MFC/SDI project Where I am using CListView as a default View.
But the thing is, I have applied ImageList to the CListCtrl
but these Images are not clearly displayed.
As shown in the picture below.
Below is the code for creating new image List.
Creating ImageList where m_ImgList is a member of CImageList.
if(m_ImgList->m_hImageList == NULL || m_ImgList->DeleteImageList() == TRUE)
{
m_ImgList->Create(16,16, ILC_COLOR,0, 1);
}
Then I am creating images by using BLOB data from database.
Here, pByte is BYTE* to hold BLOB Data.
HGLOBAL hGlobal = ::GlobalAlloc(GMEM_MOVEABLE, nbytes+5);
LPVOID pV = GlobalLock(hGlobal);
memcpy(pV, pByte, nbytes);
GlobalUnlock(hGlobal);
LPSTREAM pstm = NULL;
HRESULT hr = CreateStreamOnHGlobal(hGlobal, TRUE, &pstm);
CImage image;
image.Load(pstm);
if (image == NULL)
{
image.Load(NILIMAGE);
}
CPaintDC dc(this);
CDC pMDC;
pMDC.CreateCompatibleDC(&dc);
CBitmap pb;
pb.CreateCompatibleBitmap(&dc, iNewWidth, iNewHeight);
CBitmap *pob = (CBitmap*)pMDC.SelectObject(&pb);
image.StretchBlt(pMDC.m_hDC,0, 0, iNewWidth, iNewHeight,
0, 0, image.GetWidth(), image.GetHeight(), SRCCOPY);
pMDC.SelectObject(pob);
Adding images to the image list
if((m_ImgList->Add(&pb, RGB(0,0,0)))== -1)
{
_T("undone");
}
if(hGlobal != NULL)
::GlobalFree(hGlobal);
Can anyone tell me how can I do that?
Thank you in Advance.
and Sorry for bad English.
Related
I loaded PNG file using GDI+.
My source use HBITMAP so I convert PNG to HBITMAP.
PNG file has a transparent background but HBITMAP has a background.
I want to remove backround from HBITMAP.
I don't really have enough information. This is how I load transparent PNG files:
// Based on afxbutton.cpp's static function ButtonLoadBitmap
HBITMAP __stdcall CMeetingScheduleAssistantApp::ButtonLoadBitmap(UINT uiBmpResId)
{
if (uiBmpResId == 0)
{
return nullptr;
}
LPCTSTR lpszResourceName = MAKEINTRESOURCE(uiBmpResId);
ENSURE(lpszResourceName != nullptr);
HBITMAP hbmp = nullptr;
// Try to load PNG image first:
CPngImage pngImage;
if (pngImage.Load(lpszResourceName))
{
hbmp = (HBITMAP)pngImage.Detach();
}
else
{
HINSTANCE hinstRes = AfxFindResourceHandle(lpszResourceName, RT_BITMAP);
if (hinstRes == nullptr)
{
return nullptr;
}
UINT uiLoadImageFlags = LR_CREATEDIBSECTION | LR_LOADMAP3DCOLORS;
hbmp = (HBITMAP) ::LoadImage(hinstRes, lpszResourceName, IMAGE_BITMAP, 0, 0, uiLoadImageFlags);
}
return hbmp;
}
My code is designed to load a resource but you can adjust it to work with external files.
I have a bitmap class that has a load function for loading the bitmap from either file path or resource ID. This part works fine.
void GtBitmap::Load()
{
LPTSTR szFileName;
szFileName = (LPTSTR)m_strPath.c_str();
// Check for valid .BMP file path
if (m_strPath.size() > 0)
{
// Open .BMP file
m_pFile = fopen(m_strPath.c_str(), ("rb"));
if (m_pFile != NULL)
{
m_hBitmap = (HBITMAP)LoadImage (GetModuleHandle(NULL), szFileName, IMAGE_BITMAP, 0, 0, LR_SHARED | LR_LOADFROMFILE);
GetObject(m_hBitmap, sizeof(m_bmap), &m_bmap);
int i = 1;
}
}
else if (m_intResourceID != 0)
{
m_hBitmap = (HBITMAP)LoadImage(GetModuleHandle(NULL), MAKEINTRESOURCE(m_intResourceID), IMAGE_BITMAP, 0, 0, LR_SHARED);
GetObject(m_hBitmap, sizeof(m_bmap), &m_bmap);
int i = 1;
}
}
However, when I try to render it in my code block, the SelectObject returns null. Here is the code for that section of the painter class.
void GtPainterGDI::GtDrawBitmap(GtRectI & target, GtBitmap & bitmap, bool blnOffset)
{
GtCanvas topCv = m_arrCanvas.back();
HDC hdcMem = CreateCompatibleDC(topCv.m_hdcParent);
HBITMAP hbmOld = (HBITMAP)SelectObject(hdcMem, bitmap.m_hBitmap);
DWORD lastError = GetLastError();
bool success = BitBlt(hdcMem, target.GetLeft(), target.GetTop(),
target.Width(), target.Height(), hdcMem, 0, 0, SRCCOPY);
SelectObject(hdcMem, bitmap.m_hBitmap);
DeleteDC(hdcMem);
};
The SelectObject() returns null and the image is not drawn. I can only get the image to show up if I use a LoadImage() in that paint function. However I don't want to load the image every time I want to paint. I should be able to load the image once in the Load function or constructor of the bitmap, then use the handle in the paint function.
If anyone could please provide an example of loading an image in a constructor and then painting it elsewhere in the codes WM_PAINT or equivalent painting function I would appreciate it. The code is a new version of the GT graphical user interface library. I plan on posting a new version on codeproject in the next few days or so. I have to do some cleanup first...
Thanks in advance.
HINSTANCE parameter in LoadImage should be NULL when loading the image from file. Use GetModuleHandle(NULL) only when loading from resource.
m_hBitmap = (HBITMAP)LoadImage(NULL, m_strPath.c_str(),
IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
if (!m_hBitmap)
{
//report error
}
Also LR_SHARED is not necessary here.
When testing for file's exist, you can use std::ifstream. Example:
#include <fstream>
...
bool test = std::ifstream(m_strPath).good();
This will test for file and close the file handle right away.
Make sure to select hbmOld before deleting hdcMem:
HBITMAP hbmOld = (HBITMAP)SelectObject(hdcMem, bitmap.m_hBitmap);
BitBlt(...)
//SelectObject(hdcMem, bitmap.m_hBitmap); <<= remove this
SelectObject(hdcMem, hbmOld);
DeleteDC(hdcMem);
I try to load a bmp to my MFC Picture Control.
void CMFCAppDlg::OnBnClickedButtonload()
{
CFileDialog dlg(TRUE);
int result=dlg.DoModal();
if(result==IDOK)
{
MyBmpFile::Instance() -> setPath (dlg.GetPathName());
UpdateData(FALSE);
}
HANDLE hBitmap = LoadImage(0, MyBmpFile::Instance() -> getPath(), IMAGE_BITMAP,0,0,LR_LOADFROMFILE);
CBitmap m_bitmap;
m_bitmap.Attach((HBITMAP)hBitmap);
CDC dc, *pDC;
BITMAP bmp;
m_bitmap.LoadBitmapW(IDB_BITMAP);
m_bitmap.GetBitmap(&bmp);
pDC = this->GetDC();
dc.CreateCompatibleDC(pDC);
dc.SelectObject(m_bitmap);
pDC->BitBlt(200, 200, bmp.bmWidth, bmp.bmHeight, &dc,0 , 0, SRCCOPY);
m_bitmap.DeleteObject();
m_bitmap.Detach();
}
This code returns me an error after I select an item in dialog box. Problem is with LoadImage() it returns NULL. But actually I dont know what im doing wrong with that.
Ok, I used CImage to draw this bmp, anyway i did not solve the problem with LoadImage(). I try to make it in static way like: L"D:\\e.bmp" or _T("D:\\e.bmp") but even there problem is the same as before.
void CMFCAppDlg::OnBnClickedButtonload()
{
CFileDialog dlg(TRUE);
int result=dlg.DoModal();
if(result==IDOK)
{
MyBmpFile::Instance() -> setPath (dlg.GetPathName());
UpdateData(FALSE);
}
CImage image;
image.Load( MyBmpFile::Instance() ->getPath() );
CDC dc, *pDC;
pDC = this->GetDC();
dc.CreateCompatibleDC(pDC);
image.Draw(pDC -> GetSafeHdc(),0,0);
}
Following may be of help:
INSTANCE hInst = AfxGetInstanceHandle();
HBITMAP hBmp = (HBITMAP)LoadImage(hInst, L"path\to\file.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
Couple of things to check:
Are you using 1-byte or 2-byte characters. Use the L macro for the latter.
Is the path to your file correctly specified (e.g. could be relative to where the program happens to run from)
Can you load the file manually as a bitmap as in the example below?
Code to load a file manually as a bitmap:
CFile file;
if (file.Open(L"C:\\Tmp\\Example.bmp", CFile::modeRead))
{
// Read file header
BITMAPFILEHEADER bmfHeader;
if (file.Read((LPSTR) &bmfHeader, sizeof(bmfHeader)) == sizeof(bmfHeader))
{
// File type should be 'BM'
if (bmfHeader.bfType == ((WORD)('M' << 8)| 'B'))
{
BITMAPINFOHEADER bmiHeader;
if (file.Read((LPSTR) &bmiHeader, sizeof(bmiHeader)) == sizeof(bmiHeader))
{
int width = bmiHeader.biWidth;
int height = bmiHeader.biHeight;
}
}
}
file.Close();
}
I want to load the icon of an .exe in a CImage object, in order to easily display and save it in a database. My problem is that I have an HICON and I seem to only be able to load/attach an HBITMAP to a CImage object.
SHFILEINFO sfi;
Cimage icon;
DWORD ret = SHGetFileInfo(path, 0, &sfi, sizeof(SHFILEINFO), SHGFI_ICON | SHGFI_SMALLICON | SHGFI_DISPLAYNAME);
if(ret != 0) {
// copy info
hIcon = sfi.hIcon;
if(hIcon != lastHIcon && hIcon != 0) {
// This does not work, needs a HBITMAP instead of a HICON
icon.Attach(hIcon);
}
}
Is there any easy method of doing this, or do I need to render the HICON to a DC first? It just seems to me that there should be a solution that does not require me to be a GDI expert.
I have a bitmap of large dimension (2000 x 2000) i need to shrink that bitmap to a small dimension (150 x 150). i have written a code for it, but its not working. Can anybody help in finding the problem? The problem is the destination bitmap is just blank. I am selecting wrong DC's? I have made sure that both the source and destinations are correct. After doing bitblt do i need to do some more thing to destination bitmap?
BOOL ReSizeBitmap(CBitmap *pBitmap, CBitmap *pNewBitmap)
{
// Get new bitmap size
BITMAP bmOld;
if( !pBitmap->GetBitmap(&bmOld) )
{
return FALSE;
}
CRect rcPrev(0, 0, bmOld.bmWidth, bmOld.bmHeight);
int newWidth = 150;
int newHeight = 150;
if( newWidth < 1 || newHeight < 1 )
{
::SetLastError(ERROR_INVALID_PARAMETER);
return FALSE;
}
BOOL bResult = FALSE;
try
{
CDC dcDest;
CDC dcSource;
dcSource.CreateCompatibleDC(NULL);
dcDest.CreateCompatibleDC(NULL);
CBitmap* pSourceOld = dcSource.SelectObject(pBitmap);
CBitmap* pDestold = dcDest.SelectObject(pNewBitmap);
if( !pNewBitmap->CreateCompatibleBitmap(
&dcDest, newWidth, newHeight) )
{
return FALSE;
}
int oldStretchMode = dcDest.SetStretchBltMode(HALFTONE);
bResult = dcDest.StretchBlt(
0, 0, 150, 150,
&dcSource, 0, 0, bmOld.bmWidth, bmOld.bmHeight,
SRCCOPY);
dcDest.SetStretchBltMode(oldStretchMode);
dcSource.SelectObject(pSourceOld);
dcDest.SelectObject(pDestold);
bResult = TRUE;
}
catch(CResourceException* /*e*/)
{
}
return bResult;
}
Well even if the code works there is some cleaniing up to do.
RAII is one of the idiom you realy need when you are working in MFC!
if( !pNewBitmap->CreateCompatibleBitmap(&dcDest, newWidth, newHeight) )
{
return FALSE;
}
When you return FALSE or there is an exception you haven't called
cSource.SelectObject(pSourceOld);
dcDest.SelectObject(pDestold);
to cleanup before you left the function.
Create a small helper class to cleanup all the time, you don't have to worry about return or throw statements.
class SelectObjectAndCleanUp
{
CDC& deviceContext;
CBitmap *const oldSource;
public:
SelectObjectCleanUp( CDC& deviceContext, CBitmap* source )
: deviceContext(deviceContext),
oldSource( deviceContext.SelectObject(source) ) {
}
~SelectObjectCleanUp() {
deviceContext.SelectObject(oldSource)
}
};
// use of the helper
SelectObjectCleanUp sourceSelectionAndCleanup(dcSource, pBitmap );
SelectObjectCleanUp destionationSelectionAndCleanup(dcDest, pNewBitmap );
I'm not too familiar with C++, but are you selecting the new bitmap into your new DC before it's created? Also, when you call CreateCompatibleBitmap, I think you want to use your screen DC (the one you used to create the destination DC), not your compatible memory DC. So, get the screen DC with GetDC, and pass that into both CreateCompatibleDC AND CreateCompatibleBitmap.
There is a great free C++ image library called CxImage that is open source under the zlib license.
No need to reinvent the wheel.
Download http://www.gdiwatch.com/, it may show you where the error is (it can be made to work with vs 2008, too - just copy the registry keys manually from the vs2005 to vs2008 directories)
Have you tried doing the CreateCompatibleBitmap() before the SelectObject() call?
Does GetBitmap() of the new bitmap return the correct size, i.e. is the new bitmap valid?
The rest seem ok, it should work like this I believe. Does it work with other StretchBltModes?
Thanks to all of the guys who peeped and suggested solutions, any how after some debugging i found the problem. Here is the solution!!!
CBitmap *SrcBmp;
HBITMAP hBmp;
hBmp= (HBITMAP)LoadImage( NULL, L"c:\\source.bmp", IMAGE_BITMAP, 0,0, LR_LOADFROMFILE );
SrcBmp = CBitmap::FromHandle(hBmp);
BITMAP BmpInfo;
SrcBmp->GetBitmap(&BmpInfo);
CDC SrcDC;
SrcDC.CreateCompatibleDC(NULL);
CBitmap DestBmp;
DestBmp.CreateCompatibleBitmap(&SrcDC,150,150);
CDC DestDC;
DestDC.CreateCompatibleDC(NULL);
CBitmap *pOldBmp1 = SrcDC.SelectObject(SrcBmp);
CBitmap *pOldBmp2 = DestDC.SelectObject(&DestBmp);
DestDC.StretchBlt(0,0,150,150,&SrcDC,0,0,BmpInfo.bmWidth,BmpInfo.bmHeight,SRCCOPY);
CImage image;
image.Attach(DestBmp);
image.Save(_T("C:\\test.bmp"), Gdiplus::ImageFormatBMP);
SrcDC.SelectObject(pOldBmp1);
DestDC.SelectObject(pOldBmp2);