我写了一些代码,可以通过GDI+从自定义的C++ IStream中加载PNG文件。它在其他机器上都很好用,但在Vista机器上运行时总是崩溃。
在使用VS 2008编译时,我发现在
我将程序简化到了最基本的程度。我直接从Microsoft的文档中复制了一个FileStream。当使用
简而言之,在Vista上,通过
跟踪和调试显示它确实对IStream类进行了一些调用。它在
除了引用计数之外,它调用的唯一IStream方法是
调用堆栈如下:
- ntdll.dll!_DbgBreakPoint @ 0() + 0x1字节 - ntdll.dll!_RtlpBreakPointHeap@4() + 0x28字节 - ntdll.dll!_RtlpValidateHeapEntry@12() + 0x70a3c字节 - ntdll.dll!_RtlDebugFreeHeap@12() + 0x9a字节 - ntdll.dll!@ RtlpFreeHeap@16() + 0x13cdd字节 - ntdll.dll!_RtlFreeHeap@12() + 0x2e49字节 - kernel32.dll!_HeapFree@12() + 0x14字节 - ole32.dll!CRetailMalloc_Free() + 0x1c字节 - ole32.dll!_CoTaskMemFree@4() + 0x13字节 - GdiPlus.dll!GpPngDecoder :: GetImageInfo() + 0x68字节 - GdiPlus.dll!GpDecodedImage :: InternalGetImageInfo() + 0x3c字节 - GdiPlus.dll!GpDecodedImage :: GetImageInfo() + 0x18字节 - GdiPlus.dll!CopyOnWriteBitmap :: CopyOnWriteBitmap() + 0x49字节 - GdiPlus.dll!CopyOnWriteBitmap :: Create() + 0x1d字节 - GdiPlus.dll!GpBitmap :: GpBitmap() + 0x2c字节
我无法找到其他人有同样的问题,所以我认为我的实现有问题...
在使用VS 2008编译时,我发现在
IStream::AddRef
方法中插入一些代码,比如cout
,可以解决这个问题。但在使用VS 2010编译时,无论是否插入代码,它仍然会崩溃。我将程序简化到了最基本的程度。我直接从Microsoft的文档中复制了一个FileStream。当使用
Bitmap::FromFile
时,它可以加载PNG文件。当使用FromFile
或FromStream
时,它可以加载JPEG、GIF和BMP文件。简而言之,在Vista上,通过
Bitmap::FromStream
加载PNG文件会导致崩溃。#pragma comment(lib, "gdiplus.lib")
#include <iostream>
#include <objidl.h>
#include <gdiplus.h>
class FileStream : public IStream
{
public:
FileStream(HANDLE hFile)
{
_refcount = 1;
_hFile = hFile;
}
~FileStream()
{
if (_hFile != INVALID_HANDLE_VALUE)
{
::CloseHandle(_hFile);
}
}
public:
HRESULT static OpenFile(LPCWSTR pName, IStream ** ppStream, bool fWrite)
{
HANDLE hFile = ::CreateFileW(pName, fWrite ? GENERIC_WRITE : GENERIC_READ, FILE_SHARE_READ,
NULL, fWrite ? CREATE_ALWAYS : OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if (hFile == INVALID_HANDLE_VALUE)
return HRESULT_FROM_WIN32(GetLastError());
*ppStream = new FileStream(hFile);
if(*ppStream == NULL)
CloseHandle(hFile);
return S_OK;
}
virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, void ** ppvObject)
{
if (iid == __uuidof(IUnknown)
|| iid == __uuidof(IStream)
|| iid == __uuidof(ISequentialStream))
{
*ppvObject = static_cast<IStream*>(this);
AddRef();
return S_OK;
} else
return E_NOINTERFACE;
}
virtual ULONG STDMETHODCALLTYPE AddRef(void)
{
return (ULONG)InterlockedIncrement(&_refcount);
}
virtual ULONG STDMETHODCALLTYPE Release(void)
{
ULONG res = (ULONG) InterlockedDecrement(&_refcount);
if (res == 0)
delete this;
return res;
}
// ISequentialStream Interface
public:
virtual HRESULT STDMETHODCALLTYPE Read(void* pv, ULONG cb, ULONG* pcbRead)
{
ULONG local_pcbRead;
BOOL rc = ReadFile(_hFile, pv, cb, &local_pcbRead, NULL);
if (pcbRead) *pcbRead = local_pcbRead;
return (rc) ? S_OK : HRESULT_FROM_WIN32(GetLastError());
}
virtual HRESULT STDMETHODCALLTYPE Write(void const* pv, ULONG cb, ULONG* pcbWritten)
{
BOOL rc = WriteFile(_hFile, pv, cb, pcbWritten, NULL);
return rc ? S_OK : HRESULT_FROM_WIN32(GetLastError());
}
// IStream Interface
public:
virtual HRESULT STDMETHODCALLTYPE SetSize(ULARGE_INTEGER)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE CopyTo(IStream*, ULARGE_INTEGER, ULARGE_INTEGER*,
ULARGE_INTEGER*)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE Commit(DWORD)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE Revert(void)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE LockRegion(ULARGE_INTEGER, ULARGE_INTEGER, DWORD)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE UnlockRegion(ULARGE_INTEGER, ULARGE_INTEGER, DWORD)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE Clone(IStream **)
{
return E_NOTIMPL;
}
virtual HRESULT STDMETHODCALLTYPE Seek(LARGE_INTEGER liDistanceToMove, DWORD dwOrigin,
ULARGE_INTEGER* lpNewFilePointer)
{
DWORD dwMoveMethod;
switch(dwOrigin)
{
case STREAM_SEEK_SET:
dwMoveMethod = FILE_BEGIN;
break;
case STREAM_SEEK_CUR:
dwMoveMethod = FILE_CURRENT;
break;
case STREAM_SEEK_END:
dwMoveMethod = FILE_END;
break;
default:
return STG_E_INVALIDFUNCTION;
break;
}
if (SetFilePointerEx(_hFile, liDistanceToMove, (PLARGE_INTEGER) lpNewFilePointer,
dwMoveMethod) == 0)
return HRESULT_FROM_WIN32(GetLastError());
return S_OK;
}
virtual HRESULT STDMETHODCALLTYPE Stat(STATSTG* pStatstg, DWORD grfStatFlag)
{
if (GetFileSizeEx(_hFile, (PLARGE_INTEGER) &pStatstg->cbSize) == 0)
return HRESULT_FROM_WIN32(GetLastError());
return S_OK;
}
private:
volatile HANDLE _hFile;
volatile LONG _refcount;
};
#define USE_STREAM
int main()
{
Gdiplus::GdiplusStartupInput gdiplusStartupInput;
ULONG_PTR gdiplusToken;
Gdiplus::GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
Gdiplus::Bitmap *bmp;
#ifndef USE_STREAM
bmp = Gdiplus::Bitmap::FromFile(L"test.png", false);
if (!bmp)
{
std::cerr << " Unable to open image file." << std::endl;
return 1;
}
#else
IStream *s;
if (FileStream::OpenFile(L"test.png", &s, false) != S_OK)
{
std::cerr << "Unable to open image file." << std::endl;
return 1;
}
bmp = Gdiplus::Bitmap::FromStream(s, false);
#endif
std::cout << "Image is " << bmp->GetWidth() << " by " << bmp->GetHeight() << std::endl;
Gdiplus::GdiplusShutdown(gdiplusToken);
#ifdef USE_STREAM
s->Release();
#endif
return 0;
}
跟踪和调试显示它确实对IStream类进行了一些调用。它在
GdiPlusBitmap.h
中的lastResult = DllExports::GdipCreateBitmapFromStream(stream, &bitmap);
内部崩溃,这是对扁平API的静态内联包装器。除了引用计数之外,它调用的唯一IStream方法是
stat
(用于文件大小),read
和seek
。调用堆栈如下:
- ntdll.dll!_DbgBreakPoint @ 0() + 0x1字节 - ntdll.dll!_RtlpBreakPointHeap@4() + 0x28字节 - ntdll.dll!_RtlpValidateHeapEntry@12() + 0x70a3c字节 - ntdll.dll!_RtlDebugFreeHeap@12() + 0x9a字节 - ntdll.dll!@ RtlpFreeHeap@16() + 0x13cdd字节 - ntdll.dll!_RtlFreeHeap@12() + 0x2e49字节 - kernel32.dll!_HeapFree@12() + 0x14字节 - ole32.dll!CRetailMalloc_Free() + 0x1c字节 - ole32.dll!_CoTaskMemFree@4() + 0x13字节 - GdiPlus.dll!GpPngDecoder :: GetImageInfo() + 0x68字节 - GdiPlus.dll!GpDecodedImage :: InternalGetImageInfo() + 0x3c字节 - GdiPlus.dll!GpDecodedImage :: GetImageInfo() + 0x18字节 - GdiPlus.dll!CopyOnWriteBitmap :: CopyOnWriteBitmap() + 0x49字节 - GdiPlus.dll!CopyOnWriteBitmap :: Create() + 0x1d字节 - GdiPlus.dll!GpBitmap :: GpBitmap() + 0x2c字节
我无法找到其他人有同样的问题,所以我认为我的实现有问题...
stat
结构体。然而...我认为你是对的。罪魁祸首看起来像是pwcsName
。在我的真实项目代码中,我在图像加载期间没有设置该字段,因为Microsoft传递了STATFLAG_NONAME
字段,这意味着他们不想要名称。然而,如果pwcsName
非空,则似乎它们仍然在PNG加载时使用名称。我猜他们在Vista GDI库上至少有类似于if (s->pwcsName) free(s->pwcsName)
的东西。 - MatthewpwcsName
指针设置为非调试值,我得出结论:在Vista和Windows 7 GDI+库(或相关的某些东西)中存在不同的行为。如果通过STATFLAG_NONAME
传递参数,则Windows 7永远不会释放它,但是Vista总是会释放它。当STATFLAG_NONAME
被设置时,将其设为NULL
可以解决此问题。 - Matthew