C语言仅使用Win32保存HBITMAP为*.bmp文件

我在纯Win32项目中有一个HBITMAP(没有使用外部库)。我可以只使用Winapi和/或CRT函数将其导出到*.bmp文件，这样我就不必为项目添加依赖关系了吗?

没有API可以直接保存到文件中，因为通常，拥有位图句柄并不意味着您可以直接访问位图数据。您的解决方案是通过数据访问(DIB)将位图复制到另一个位图中，然后使用它将数据写入文件。

您通常要么使用CreateDIBSection创建另一个位图，要么使用GetDIBits获得位图数据。

CreateFile, WriteFile写入文件

你写:BITMAPFILEHEADER，然后BITMAPINFOHEADER，然后调色板(当比特/像素超过8时你通常没有)，然后是数据本身。

参见:

c++: Hbitmap/BITMAP into .bmp文件(这个答案)
使用hBitmap = CreateDIBSection()在C Win32中保存。bmp文件
在MSDN上存储图像

这是来自MSDN文章的代码(注意您需要定义errhandler()函数):

PBITMAPINFO CreateBitmapInfoStruct(HWND hwnd, HBITMAP hBmp)
{ 
    BITMAP bmp; 
    PBITMAPINFO pbmi; 
    WORD    cClrBits; 
    // Retrieve the bitmap color format, width, and height.  
    if (!GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp)) 
        errhandler("GetObject", hwnd); 
    // Convert the color format to a count of bits.  
    cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel); 
    if (cClrBits == 1) 
        cClrBits = 1; 
    else if (cClrBits <= 4) 
        cClrBits = 4; 
    else if (cClrBits <= 8) 
        cClrBits = 8; 
    else if (cClrBits <= 16) 
        cClrBits = 16; 
    else if (cClrBits <= 24) 
        cClrBits = 24; 
    else cClrBits = 32; 
    // Allocate memory for the BITMAPINFO structure. (This structure  
    // contains a BITMAPINFOHEADER structure and an array of RGBQUAD  
    // data structures.)  
    if (cClrBits < 24) 
        pbmi = (PBITMAPINFO) LocalAlloc(LPTR, 
        sizeof(BITMAPINFOHEADER) + 
        sizeof(RGBQUAD) * (1<< cClrBits)); 
    // There is no RGBQUAD array for these formats: 24-bit-per-pixel or 32-bit-per-pixel 
    else 
        pbmi = (PBITMAPINFO) LocalAlloc(LPTR, 
        sizeof(BITMAPINFOHEADER)); 
    // Initialize the fields in the BITMAPINFO structure.  
    pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER); 
    pbmi->bmiHeader.biWidth = bmp.bmWidth; 
    pbmi->bmiHeader.biHeight = bmp.bmHeight; 
    pbmi->bmiHeader.biPlanes = bmp.bmPlanes; 
    pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel; 
    if (cClrBits < 24) 
        pbmi->bmiHeader.biClrUsed = (1<<cClrBits); 
    // If the bitmap is not compressed, set the BI_RGB flag.  
    pbmi->bmiHeader.biCompression = BI_RGB; 
    // Compute the number of bytes in the array of color  
    // indices and store the result in biSizeImage.  
    // The width must be DWORD aligned unless the bitmap is RLE 
    // compressed. 
    pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8
        * pbmi->bmiHeader.biHeight; 
    // Set biClrImportant to 0, indicating that all of the  
    // device colors are important.  
    pbmi->bmiHeader.biClrImportant = 0; 
    return pbmi; 
} 
void CreateBMPFile(HWND hwnd, LPTSTR pszFile, PBITMAPINFO pbi, 
                   HBITMAP hBMP, HDC hDC) 
{ 
    HANDLE hf;                 // file handle  
    BITMAPFILEHEADER hdr;       // bitmap file-header  
    PBITMAPINFOHEADER pbih;     // bitmap info-header  
    LPBYTE lpBits;              // memory pointer  
    DWORD dwTotal;              // total count of bytes  
    DWORD cb;                   // incremental count of bytes  
    BYTE *hp;                   // byte pointer  
    DWORD dwTmp; 
    pbih = (PBITMAPINFOHEADER) pbi; 
    lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);
    if (!lpBits) 
        errhandler("GlobalAlloc", hwnd); 
    // Retrieve the color table (RGBQUAD array) and the bits  
    // (array of palette indices) from the DIB.  
    if (!GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi, 
        DIB_RGB_COLORS)) 
    {
        errhandler("GetDIBits", hwnd); 
    }
    // Create the .BMP file.  
    hf = CreateFile(pszFile, 
        GENERIC_READ | GENERIC_WRITE, 
        (DWORD) 0, 
        NULL, 
        CREATE_ALWAYS, 
        FILE_ATTRIBUTE_NORMAL, 
        (HANDLE) NULL); 
    if (hf == INVALID_HANDLE_VALUE) 
        errhandler("CreateFile", hwnd); 
    hdr.bfType = 0x4d42;        // 0x42 = "B" 0x4d = "M"  
    // Compute the size of the entire file.  
    hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + 
        pbih->biSize + pbih->biClrUsed 
        * sizeof(RGBQUAD) + pbih->biSizeImage); 
    hdr.bfReserved1 = 0; 
    hdr.bfReserved2 = 0; 
    // Compute the offset to the array of color indices.  
    hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + 
        pbih->biSize + pbih->biClrUsed 
        * sizeof (RGBQUAD); 
    // Copy the BITMAPFILEHEADER into the .BMP file.  
    if (!WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), 
        (LPDWORD) &dwTmp,  NULL)) 
    {
        errhandler("WriteFile", hwnd); 
    }
    // Copy the BITMAPINFOHEADER and RGBQUAD array into the file.  
    if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) 
        + pbih->biClrUsed * sizeof (RGBQUAD), 
        (LPDWORD) &dwTmp, ( NULL)))
        errhandler("WriteFile", hwnd); 
    // Copy the array of color indices into the .BMP file.  
    dwTotal = cb = pbih->biSizeImage; 
    hp = lpBits; 
    if (!WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL)) 
        errhandler("WriteFile", hwnd); 
    // Close the .BMP file.  
    if (!CloseHandle(hf)) 
        errhandler("CloseHandle", hwnd); 
    // Free memory.  
    GlobalFree((HGLOBAL)lpBits);
}

HBITMAP到*.bmp文件的一个函数代码

BOOL SaveHBITMAPToFile(HBITMAP hBitmap, LPCTSTR lpszFileName)
{
    HDC hDC;
    int iBits;
    WORD wBitCount;
    DWORD dwPaletteSize = 0, dwBmBitsSize = 0, dwDIBSize = 0, dwWritten = 0;
    BITMAP Bitmap0;
    BITMAPFILEHEADER bmfHdr;
    BITMAPINFOHEADER bi;
    LPBITMAPINFOHEADER lpbi;
    HANDLE fh, hDib, hPal, hOldPal2 = NULL;
    hDC = CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);
    iBits = GetDeviceCaps(hDC, BITSPIXEL) * GetDeviceCaps(hDC, PLANES);
    DeleteDC(hDC);
    if (iBits <= 1)
        wBitCount = 1;
    else if (iBits <= 4)
        wBitCount = 4;
    else if (iBits <= 8)
        wBitCount = 8;
    else
        wBitCount = 24;
    GetObject(hBitmap, sizeof(Bitmap0), (LPSTR)&Bitmap0);
    bi.biSize = sizeof(BITMAPINFOHEADER);
    bi.biWidth = Bitmap0.bmWidth;
    bi.biHeight = -Bitmap0.bmHeight;
    bi.biPlanes = 1;
    bi.biBitCount = wBitCount;
    bi.biCompression = BI_RGB;
    bi.biSizeImage = 0;
    bi.biXPelsPerMeter = 0;
    bi.biYPelsPerMeter = 0;
    bi.biClrImportant = 0;
    bi.biClrUsed = 256;
    dwBmBitsSize = ((Bitmap0.bmWidth * wBitCount + 31) & ~31) / 8
        * Bitmap0.bmHeight;
    hDib = GlobalAlloc(GHND, dwBmBitsSize + dwPaletteSize + sizeof(BITMAPINFOHEADER));
    lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib);
    *lpbi = bi;
    hPal = GetStockObject(DEFAULT_PALETTE);
    if (hPal)
    {
        hDC = GetDC(NULL);
        hOldPal2 = SelectPalette(hDC, (HPALETTE)hPal, FALSE);
        RealizePalette(hDC);
    }

    GetDIBits(hDC, hBitmap, 0, (UINT)Bitmap0.bmHeight, (LPSTR)lpbi + sizeof(BITMAPINFOHEADER)
        + dwPaletteSize, (BITMAPINFO *)lpbi, DIB_RGB_COLORS);
    if (hOldPal2)
    {
        SelectPalette(hDC, (HPALETTE)hOldPal2, TRUE);
        RealizePalette(hDC);
        ReleaseDC(NULL, hDC);
    }
    fh = CreateFile(lpszFileName, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS,
        FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);
    if (fh == INVALID_HANDLE_VALUE)
        return FALSE;
    bmfHdr.bfType = 0x4D42; // "BM"
    dwDIBSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + dwPaletteSize + dwBmBitsSize;
    bmfHdr.bfSize = dwDIBSize;
    bmfHdr.bfReserved1 = 0;
    bmfHdr.bfReserved2 = 0;
    bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER) + (DWORD)sizeof(BITMAPINFOHEADER) + dwPaletteSize;
    WriteFile(fh, (LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER), &dwWritten, NULL);
    WriteFile(fh, (LPSTR)lpbi, dwDIBSize, &dwWritten, NULL);
    GlobalUnlock(hDib);
    GlobalFree(hDib);
    CloseHandle(fh);
    return TRUE;
}

另一个极简的选择是使用OLE的IPicture。它一直存在，仍然是Win32 API的一部分:

#define _S(exp) (([](HRESULT hr) { if (FAILED(hr)) _com_raise_error(hr); return hr; })(exp));
PICTDESC pictdesc = {};
pictdesc.cbSizeofstruct = sizeof(pictdesc);
pictdesc.picType = PICTYPE_BITMAP;
pictdesc.bmp.hbitmap = hBitmap;
CComPtr<IPicture> picture;
_S( OleCreatePictureIndirect(&pictdesc, __uuidof(IPicture), FALSE, (LPVOID*)&picture) );
// Save to a stream
CComPtr<IStream> stream;
_S( CreateStreamOnHGlobal(NULL, TRUE, &stream) );
LONG cbSize = 0;
_S( picture->SaveAsFile(stream, TRUE, &cbSize) );
// Or save to a file
CComPtr<IPictureDisp> disp;
_S( picture->QueryInterface(&disp) );
_S( OleSavePictureFile(disp, CComBSTR("C:\Temp\File.bmp")) );

我将把这个自包含的概念证明留在这里，因为我可能需要稍后查找它，因为它不是很明显。它截取桌面窗口的截图，并将其保存为bitmap.bmp:

#include <Windows.h>
#include <stdio.h>
#include <assert.h>
/* forward declarations */
PBITMAPINFO CreateBitmapInfoStruct(HBITMAP);
void CreateBMPFile(LPTSTR pszFile, HBITMAP hBMP); 
int main(int argc, char **argv);
PBITMAPINFO CreateBitmapInfoStruct(HBITMAP hBmp)
{ 
    BITMAP bmp; 
    PBITMAPINFO pbmi; 
    WORD    cClrBits; 
    // Retrieve the bitmap color format, width, and height.  
    assert(GetObject(hBmp, sizeof(BITMAP), (LPSTR)&bmp)); 
    // Convert the color format to a count of bits.  
    cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel); 
    if (cClrBits == 1) 
        cClrBits = 1; 
    else if (cClrBits <= 4) 
        cClrBits = 4; 
    else if (cClrBits <= 8) 
        cClrBits = 8; 
    else if (cClrBits <= 16) 
        cClrBits = 16; 
    else if (cClrBits <= 24) 
        cClrBits = 24; 
    else cClrBits = 32; 
    // Allocate memory for the BITMAPINFO structure. (This structure  
    // contains a BITMAPINFOHEADER structure and an array of RGBQUAD  
    // data structures.)  
     if (cClrBits < 24) 
         pbmi = (PBITMAPINFO) LocalAlloc(LPTR, 
                    sizeof(BITMAPINFOHEADER) + 
                    sizeof(RGBQUAD) * (1<< cClrBits)); 
     // There is no RGBQUAD array for these formats: 24-bit-per-pixel or 32-bit-per-pixel 
     else 
         pbmi = (PBITMAPINFO) LocalAlloc(LPTR, 
                    sizeof(BITMAPINFOHEADER)); 
    // Initialize the fields in the BITMAPINFO structure.  
    pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER); 
    pbmi->bmiHeader.biWidth = bmp.bmWidth; 
    pbmi->bmiHeader.biHeight = bmp.bmHeight; 
    pbmi->bmiHeader.biPlanes = bmp.bmPlanes; 
    pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel; 
    if (cClrBits < 24) 
        pbmi->bmiHeader.biClrUsed = (1<<cClrBits); 
    // If the bitmap is not compressed, set the BI_RGB flag.  
    pbmi->bmiHeader.biCompression = BI_RGB; 
    // Compute the number of bytes in the array of color  
    // indices and store the result in biSizeImage.  
    // The width must be DWORD aligned unless the bitmap is RLE 
    // compressed. 
    pbmi->bmiHeader.biSizeImage = ((pbmi->bmiHeader.biWidth * cClrBits +31) & ~31) /8
                                  * pbmi->bmiHeader.biHeight; 
    // Set biClrImportant to 0, indicating that all of the  
    // device colors are important.  
     pbmi->bmiHeader.biClrImportant = 0; 
     return pbmi; 
 } 
void CreateBMPFile(LPTSTR pszFile, HBITMAP hBMP) 
 { 
     HANDLE hf;                 // file handle  
    BITMAPFILEHEADER hdr;       // bitmap file-header  
    PBITMAPINFOHEADER pbih;     // bitmap info-header  
    LPBYTE lpBits;              // memory pointer  
    DWORD dwTotal;              // total count of bytes  
    DWORD cb;                   // incremental count of bytes  
    BYTE *hp;                   // byte pointer  
    DWORD dwTmp;     
    PBITMAPINFO pbi;
    HDC hDC;
    hDC = CreateCompatibleDC(GetWindowDC(GetDesktopWindow()));
    SelectObject(hDC, hBMP);
    pbi = CreateBitmapInfoStruct(hBMP);
    pbih = (PBITMAPINFOHEADER) pbi; 
    lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);
    assert(lpBits) ;
    // Retrieve the color table (RGBQUAD array) and the bits  
    // (array of palette indices) from the DIB.  
    assert(GetDIBits(hDC, hBMP, 0, (WORD) pbih->biHeight, lpBits, pbi, 
        DIB_RGB_COLORS));
    // Create the .BMP file.  
    hf = CreateFile(pszFile, 
                   GENERIC_READ | GENERIC_WRITE, 
                   (DWORD) 0, 
                    NULL, 
                   CREATE_ALWAYS, 
                   FILE_ATTRIBUTE_NORMAL, 
                   (HANDLE) NULL); 
    assert(hf != INVALID_HANDLE_VALUE) ;
    hdr.bfType = 0x4d42;        // 0x42 = "B" 0x4d = "M"  
    // Compute the size of the entire file.  
    hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) + 
                 pbih->biSize + pbih->biClrUsed 
                 * sizeof(RGBQUAD) + pbih->biSizeImage); 
    hdr.bfReserved1 = 0; 
    hdr.bfReserved2 = 0; 
    // Compute the offset to the array of color indices.  
    hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) + 
                    pbih->biSize + pbih->biClrUsed 
                    * sizeof (RGBQUAD); 
    // Copy the BITMAPFILEHEADER into the .BMP file.  
    assert(WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), 
        (LPDWORD) &dwTmp,  NULL)); 
    // Copy the BITMAPINFOHEADER and RGBQUAD array into the file.  
    assert(WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER) 
                  + pbih->biClrUsed * sizeof (RGBQUAD), 
                  (LPDWORD) &dwTmp, ( NULL)));
    // Copy the array of color indices into the .BMP file.  
    dwTotal = cb = pbih->biSizeImage; 
    hp = lpBits; 
    assert(WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp,NULL)); 
    // Close the .BMP file.  
     assert(CloseHandle(hf)); 
    // Free memory.  
    GlobalFree((HGLOBAL)lpBits);
}
int main(int argc, char **argv)
{
    HWND hwnd;
    HDC hdc[2];
    HBITMAP hbitmap;
    RECT rect;
    hwnd = GetDesktopWindow();
    GetClientRect(hwnd, &rect);
    hdc[0] = GetWindowDC(hwnd);
    hbitmap = CreateCompatibleBitmap(hdc[0], rect.right, rect.bottom); 
    hdc[1] = CreateCompatibleDC(hdc[0]);
    SelectObject(hdc[1], hbitmap);    
    BitBlt (    
        hdc[1],
        0,
        0,
        rect.right,
        rect.bottom,
        hdc[0],
        0,
        0,
        SRCCOPY
    );
    CreateBMPFile("bitmap.bmp", hbitmap);
    return 0;
}

是的，使用Windows成像组件(WIC)这是可能的。WIC提供内置编码器，因此您不必手动编写位图头和数据。它还允许您选择不同的编码器(例如PNG)，只需更改一行代码。

这个过程相当直接。它由以下步骤组成:

使用GetObject从源HBITMAP检索属性(尺寸，位深度)。
创建IWICImagingFactory实例
从HBITMAP (IWICImagingFactory::CreateBitmapFromHBITMAP)创建IWICBitmap实例
创建IWICStream实例(IWICImagingFactory::CreateStream)，并将其附加到文件名(IWICStream::InitializeFromFilename)。
创建IWICBitmapEncoder实例(IWICImagingFactory::CreateEncoder)，并将其与流(IWICBitmapEncoder::Initialize)关联。
创建IWICBitmapFrameEncode实例(IWICBitmapEncoder::CreateNewFrame)，并按照源HBITMAP (IWICBitmapFrameEncode::Initialize, IWICBitmapFrameEncode::SetSize, IWICBitmapFrameEncode::SetPixelFormat)初始化。
将位图数据写入帧(IWICBitmapFrameEncode::WriteSource)。
提交帧和数据到流(IWICBitmapFrameEncode::Commit, IWICBitmapEncoder::Commit)。

翻译成代码:

#define COBJMACROS
#include <Objbase.h>
#include <wincodec.h>
#include <Windows.h>
#include <Winerror.h>
#pragma comment(lib, "Windowscodecs.lib")
HRESULT WriteBitmap(HBITMAP bitmap, const wchar_t* pathname) {
    HRESULT hr = S_OK;
    // (1) Retrieve properties from the source HBITMAP.
    BITMAP bm_info = { 0 };
    if (!GetObject(bitmap, sizeof(bm_info), &bm_info))
        hr = E_FAIL;
    // (2) Create an IWICImagingFactory instance.
    IWICImagingFactory* factory = NULL;
    if (SUCCEEDED(hr))
        hr = CoCreateInstance(&CLSID_WICImagingFactory, NULL, CLSCTX_INPROC_SERVER,
                              &IID_IWICImagingFactory, &factory);
    // (3) Create an IWICBitmap instance from the HBITMAP.
    IWICBitmap* wic_bitmap = NULL;
    if (SUCCEEDED(hr))
        hr = IWICImagingFactory_CreateBitmapFromHBITMAP(factory, bitmap, NULL,
                                                        WICBitmapIgnoreAlpha,
                                                        &wic_bitmap);
    // (4) Create an IWICStream instance, and attach it to a filename.
    IWICStream* stream = NULL;
    if (SUCCEEDED(hr))
        hr = IWICImagingFactory_CreateStream(factory, &stream);
    if (SUCCEEDED(hr))
        hr = IWICStream_InitializeFromFilename(stream, pathname, GENERIC_WRITE);
    // (5) Create an IWICBitmapEncoder instance, and associate it with the stream.
    IWICBitmapEncoder* encoder = NULL;
    if (SUCCEEDED(hr))
        hr = IWICImagingFactory_CreateEncoder(factory, &GUID_ContainerFormatBmp, NULL,
                                              &encoder);
    if (SUCCEEDED(hr))
        hr = IWICBitmapEncoder_Initialize(encoder, (IStream*)stream,
                                          WICBitmapEncoderNoCache);
    // (6) Create an IWICBitmapFrameEncode instance, and initialize it
    // in compliance with the source HBITMAP.
    IWICBitmapFrameEncode* frame = NULL;
    if (SUCCEEDED(hr))
        hr = IWICBitmapEncoder_CreateNewFrame(encoder, &frame, NULL);
    if (SUCCEEDED(hr))
        hr = IWICBitmapFrameEncode_Initialize(frame, NULL);
    if (SUCCEEDED(hr))
        hr = IWICBitmapFrameEncode_SetSize(frame, bm_info.bmWidth, bm_info.bmHeight);
    if (SUCCEEDED(hr)) {
        GUID pixel_format = GUID_WICPixelFormat24bppBGR;
        hr = IWICBitmapFrameEncode_SetPixelFormat(frame, &pixel_format);
    }
    // (7) Write bitmap data to the frame.
    if (SUCCEEDED(hr))
        hr = IWICBitmapFrameEncode_WriteSource(frame, (IWICBitmapSource*)wic_bitmap,
                                               NULL);
    // (8) Commit frame and data to stream.
    if (SUCCEEDED(hr))
        hr = IWICBitmapFrameEncode_Commit(frame);
    if (SUCCEEDED(hr))
        hr = IWICBitmapEncoder_Commit(encoder);
    // Cleanup
    if (frame)
        IWICBitmapFrameEncode_Release(frame);
    if (encoder)
        IWICBitmapEncoder_Release(encoder);
    if (stream)
        IWICStream_Release(stream);
    if (wic_bitmap)
        IWICBitmap_Release(wic_bitmap);
    if (factory)
        IWICImagingFactory_Release(factory);
    return hr;
}

下面是一个配套的测试应用程序来展示其用法。在包含任何系统头文件之前，请确保#define OEMRESOURCE允许使用OBM_图像。

int wmain(int argc, wchar_t** argv) {
    HRESULT hr = S_OK;
    hr = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
    if (FAILED(hr))
        return -1;
    HBITMAP bitmap = LoadImage(NULL, MAKEINTRESOURCE(OBM_ZOOM), IMAGE_BITMAP, 0, 0,
                               LR_DEFAULTCOLOR);
    hr = WriteBitmap(bitmap, argv[1]);
    // Cleanup
    if (bitmap)
        DeleteObject(bitmap);
    CoUninitialize();
    return 0;
}

这将加载系统提供的位图，并将其保存到命令行中作为参数指定的路径名中。

<标题>限制:

不支持alpha通道。虽然位图版本5支持alpha通道，但我不知道有什么方法可以找出，HBITMAP是否指的是具有alpha通道的位图，我也不知道如何确定它是否预乘。如果你想支持alpha通道，请确保将EnableV5Header32bppBGRA属性设置为VARIANT_TRUE(参见BMP格式:编码)。
不支持码垛位图(bpp <= 8)。如果您正在处理码垛位图，请确保在调用IWICImagingFactory::CreateBitmapFromHBITMAP时提供适当的HPALETTE。
编码器初始化为GUID_WICPixelFormat24bppBGR像素格式常量。更通用的实现将从源HBITMAP推导出兼容的像素格式。

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