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// 从文件加载图片,不独占文件,失败返回NULL
Bitmap* LoadBitmapFromFile(const TCHAR* file_name)
{
Bitmap* bmp = NULL;
HANDLE file_handle = CreateFile(file_name, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if (file_handle != INVALID_HANDLE_VALUE)
{
DWORD temp = 0;
DWORD file_size = GetFileSize(file_handle, &temp);
if (file_size && !temp) // 不处理大于4G的文件
{
// 将图片文件读到内存后,再从内存创建Bitmap
unsigned char* buffer = new unsigned char[file_size];
if (ReadFile(file_handle, buffer, file_size, &temp, NULL))
bmp = LoadBitmapFromMemory(buffer, temp);
delete [] buffer;
}
CloseHandle(file_handle);
}
return bmp;
}
// 从内存加载图片,失败返回NULL
Bitmap* LoadBitmapFromMemory(const void* memory, DWORD size)
{
Bitmap* bmp = NULL;
IStream* stream = NULL;
if (CreateStreamOnHGlobal(NULL, TRUE, &stream) == S_OK)
{
ULARGE_INTEGER uli;
uli.QuadPart = size;
stream->SetSize(uli);
if (stream->Write(memory, size, NULL) == S_OK)
bmp = new Bitmap(stream);
stream->Release();
}
return bmp;
}
IStream* pStream = NULL;
CreateStreamOnHGlobal(NULL, TRUE, &pStream);//在堆中创建流对象
pStream->Write(pPuf, nBufSize, NULL);
Bitmap *pSrcBmp = Bitmap::FromStream(pStream);
//...操作bmp
delete pSrcBmp;
pStream->Release();