先放上运行结果：

可以发现红绿蓝是从后往前的。

必须以C++方式编译代码！

// 参考资料：https://learn.microsoft.com/zh-cn/windows/win32/wic/-wic-lh
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <wincodec.h>

int main(void)
{
    CoInitialize(nullptr);

    IWICImagingFactory* fac;
    CoCreateInstance(CLSID_WICImagingFactory, nullptr, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&fac));
    
    IWICBitmapDecoder* dec;
    fac->CreateDecoderFromFilename(L"test.bmp", nullptr, GENERIC_READ, WICDecodeMetadataCacheOnDemand, &dec);
    
    IWICBitmapFrameDecode* fram;
    dec->GetFrame(0, &fram);
    
    IWICBitmap* bmp;
    fac->CreateBitmapFromSource(fram, WICBitmapCacheOnDemand, &bmp);
    UINT w, h;
    bmp->GetSize(&w, &h);
    printf("宽 %u 高 %u\n", w, h);

    IWICBitmapLock* lck;
    WICRect rc = { .X = 0, .Y = 0, .Width = (INT)w, .Height = (INT)h };
    bmp->Lock(nullptr, WICBitmapLockRead, &lck);

    UINT stride;
    lck->GetStride(&stride);
    printf("步长 %u\n", stride);
    
    UINT bufsiz;
    BYTE* v;
    lck->GetDataPointer(&bufsiz, &v);
    puts("每个像素的 RGB 值：");
    for (UINT i = 0; i < h; i++) {
        printf("第 %u 行\n", i);
        BYTE* row = v + (UINT64)i * stride;
        for (UINT j = 0; j < w; j++) {
            BYTE* p = row + 3 * j;
            printf("%-4hhu%-4hhu%-4hhu\n", p[0], p[1], p[2]);
        }
        putchar('\n');
    }

    lck->Release();
    bmp->Release();
    fram->Release();
    dec->Release();
    fac->Release();

    CoUninitialize();
    return 0;
}