MFC/QT利用COM组件接口从字体名称、粗体、斜体获取到字体文件路径的方法

MFC/QT利用COM组件接口从字体名称、粗体、斜体获取到字体文件路径的方法

这个是目前唯一能准确从字体名称+加粗+斜体三个属性定位到ttf/ttc字体路径的方法，其他的方式是没有办法区分后两个属性而且会出现不准确的问题

之前无意间在MSDN找到的资料：

IDWriteLocalFontFileLoader：：GetFilePathFromKey (dwrite.h) - Win32 apps | Microsoft Learn

#include <iostream>
#include <dwrite.h>
#include <list>
#pragma comment(lib, "dwrite.lib")

using namespace std;

list<WCHAR*> get_fonts_path(WCHAR* family_name, BOOL is_bold, BOOL is_italic)
{
    list<WCHAR*> fonts_filename_list;
    HRESULT hr;

    IDWriteFactory* dwrite_factory;
    hr = DWriteCreateFactory(DWRITE_FACTORY_TYPE_ISOLATED, __uuidof(IDWriteFactory), reinterpret_cast<IUnknown**>(&dwrite_factory));
    if (FAILED(hr))
    {
        return fonts_filename_list;
    }

    IDWriteGdiInterop* gdi_interop;
    hr = dwrite_factory->GetGdiInterop(&gdi_interop);
    if (FAILED(hr))
    {
        dwrite_factory->Release();
        return fonts_filename_list;
    }

    LOGFONT lf;
    memset(&lf, 0, sizeof(lf));
    wcscpy_s(lf.lfFaceName, LF_FACESIZE, family_name);
    lf.lfWeight = is_bold ? FW_BOLD : FW_REGULAR;
    lf.lfItalic = is_italic;
    lf.lfCharSet = DEFAULT_CHARSET;
    lf.lfOutPrecision = OUT_TT_PRECIS;
    lf.lfClipPrecision = CLIP_DEFAULT_PRECIS;
    lf.lfQuality = ANTIALIASED_QUALITY;
    lf.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;

    IDWriteFont* matching_font;
    hr = gdi_interop->CreateFontFromLOGFONT(&lf, &matching_font);
    if (FAILED(hr))
    {
        gdi_interop->Release();
        dwrite_factory->Release();
        return fonts_filename_list;
    }

    IDWriteFontFace* font_face;
    hr = matching_font->CreateFontFace(&font_face);
    if (FAILED(hr))
    {
        matching_font->Release();
        gdi_interop->Release();
        dwrite_factory->Release();
        return fonts_filename_list;
    }

    UINT file_count;
    hr = font_face->GetFiles(&file_count, NULL);
    if (FAILED(hr))
    {
        font_face->Release();
        matching_font->Release();
        gdi_interop->Release();
        dwrite_factory->Release();
        return fonts_filename_list;
    }


    IDWriteFontFile** font_files = new IDWriteFontFile * [file_count];
    hr = font_face->GetFiles(&file_count, font_files);
    if (FAILED(hr))
    {
        font_face->Release();
        matching_font->Release();
        gdi_interop->Release();
        dwrite_factory->Release();
        return fonts_filename_list;
    }

    for (int i = 0; i < file_count; i++)
    {
        LPCVOID font_file_reference_key;
        UINT font_file_reference_key_size;
        hr = font_files[i]->GetReferenceKey(&font_file_reference_key, &font_file_reference_key_size);
        if (FAILED(hr))
        {
            font_files[i]->Release();
            continue;
        }

        IDWriteFontFileLoader* loader;
        hr = font_files[i]->GetLoader(&loader);
        if (FAILED(hr))
        {
            font_files[i]->Release();
            continue;
        }

        IDWriteLocalFontFileLoader* local_loader;
        hr = loader->QueryInterface(__uuidof(IDWriteLocalFontFileLoader), (void**)&local_loader);
        if (FAILED(hr))
        {
            loader->Release();
            font_files[i]->Release();
            continue;
        }

        UINT32 path_length;
        hr = local_loader->GetFilePathLengthFromKey(font_file_reference_key, font_file_reference_key_size, &path_length);
        if (FAILED(hr))
        {
            local_loader->Release();
            loader->Release();
            font_files[i]->Release();
            continue;
        }


        WCHAR* path = new WCHAR[path_length + 1];
        hr = local_loader->GetFilePathFromKey(font_file_reference_key, font_file_reference_key_size, path, path_length + 1);
        if (FAILED(hr))
        {
            local_loader->Release();
            loader->Release();
            font_files[i]->Release();
            continue;
        }

        fonts_filename_list.push_back(path);

        local_loader->Release();
        loader->Release();
        font_files[i]->Release();

    }

    font_face->Release();
    matching_font->Release();
    gdi_interop->Release();
    dwrite_factory->Release();

    return fonts_filename_list;
}


int main() {
    list<WCHAR*> fonts_filename_list = get_fonts_path(const_cast<WCHAR*>(L"Arial"), false, true);


    for (WCHAR* font_filename : fonts_filename_list)
    {
        wcout << L"Font filename: " << font_filename << endl;
    }

    return 0;
}