GetUserPreferredUILanguages() never returns more than two languages

Question

I\'m trying to retrieve the complete list of the user\'s preferred languages from a C++/Qt application, as configured in the \"Region & language\" page in the user\'s pr

Answer 1

GlobalizationPreferences.Languages is usable from unmanaged C++ because GlobalizationPreferences has DualApiPartitionAttribute. Here is a C++/WinRT example of using GlobalizationPreferences.Languages:

#pragma once
#include <winrt/Windows.Foundation.Collections.h>
#include <winrt/Windows.System.UserProfile.h>
#include <iostream>
#pragma comment(lib, "windowsapp")

using namespace winrt;
using namespace Windows::Foundation;
using namespace Windows::System::UserProfile;

int main()
{
    winrt::init_apartment();

    for (const auto& lang : GlobalizationPreferences::Languages()) {
        std::wcout << lang.c_str() << std::endl;
    }
}

And a WRL example for those who cannot migrate to C++ 17:

#include <roapi.h>
#include <wrl.h>
#include <Windows.System.UserProfile.h>
#include <iostream>
#include <stdint.h>
#pragma comment(lib, "runtimeobject.lib")

using namespace Microsoft::WRL;
using namespace Microsoft::WRL::Wrappers;
using namespace ABI::Windows::Foundation::Collections;
using namespace ABI::Windows::System::UserProfile;

int main()
{
    RoInitializeWrapper initialize(RO_INIT_MULTITHREADED);
    if (FAILED(initialize)) {
        std::cerr << "RoInitialize failed" << std::endl;
        return 1;
    }

    ComPtr<IGlobalizationPreferencesStatics> gps;
    HRESULT hr = RoGetActivationFactory(
        HStringReference(
            RuntimeClass_Windows_System_UserProfile_GlobalizationPreferences)
            .Get(),
        IID_PPV_ARGS(&gps));
    if (FAILED(hr)) {
        std::cerr << "RoGetActivationFactory failed" << std::endl;
        return 1;
    }

    ComPtr<IVectorView<HSTRING>> langs;
    hr = gps->get_Languages(&langs);
    if (FAILED(hr)) {
        std::cerr << "Could not get Languages" << std::endl;
        return 1;
    }

    uint32_t size;
    hr = langs->get_Size(&size);
    if (FAILED(hr)) {
        std::cerr << "Could not get Size" << std::endl;
        return 1;
    }
    for (uint32_t i = 0; i < size; ++i) {
        HString lang;
        hr = langs->GetAt(i, lang.GetAddressOf());
        if (FAILED(hr)) {
            std::cerr << "Could not get Languages[" << i << "]" << std::endl;
            continue;
        }
        std::wcout << lang.GetRawBuffer(nullptr) << std::endl;
    }
}