Get system information UWP

[Cobra91151]

@Chris-Kawa

I will check it. Thank you.

[Cobra91151]

@Chris-Kawa

Any documentation how to use UWP API with Qt? In Visual Studio I included: using namespace Windows::Devices::Enumeration; and it works. When adding/including namespaces in Qt I get errors.

For example:

.h
#include <windows.devices.enumeration.h>

.cpp
DeviceAccessInformation deviceInfo;

I get error: C2065: 'DeviceAccessInformation': undeclared identifier

Thanks.

[Chris Kawa]

There are couple of ways to access UWP components with C++. Apart from the hacky c++/cx language extensions Microsoft created there's now a nice header-only library wrapper in native C++ called C++/WinRT. The great thing is it's included directly in the Windows SDK now.
When you create a Visual Studio project it has a preoperty that selects the Windows SDK version and sets up the needed include and lib paths.
If you're using qmake for your project you need to set up these paths yourself. Since C++/WinRT is a header-only library all you need is the right include path set up. Depending on which version of Windows SDK you're using and your installation path it might look something like this in your .pro file:

INCLUDEPATH += "C:/Program Files (x86)/Windows Kits/10/Include/10.0.16299.0"

After that re-run qmake (in Qt Creator menu Build -> Run qmake) and you can do:

#include  "winrt/windows.devices.enumeration.h"

For examples on how to use it you can browse through the various samples on the github page of the project.

[Cobra91151]

@Chris-Kawa

I have added the Win SDK path (INCLUDEPATH += "C:/Program Files (x86)/Windows Kits/10/Include/10.0.16299.0") to the .pro file and it is the same as your include path. Also added the #include "winrt/windows.devices.enumeration.h" to the header file but it still can't find the DeviceAccessInformation deviceInfo;, throws error: C2065: DeviceAccessInformation: undeclared identifier.

Also I have checked the samples, and add the namespace.
using namespace winrt;

and it displays the error: C2871: 'winrt': a namespace with this name does not exist

Also I have noticed the warning: : -1: warning: winrt_manifest_install.path is not defined: install target not created

I think the problem is with the wrong includes or I missing something.

[Cobra91151]

I have included the WindowsApp library but the issue still exists.

Code:
.pro

contains(QMAKE_TARGET.arch, x86_64) {
    LIBS += -L"C:/Program Files (x86)/Windows Kits/10/Lib/10.0.16299.0/um/x64" -lWindowsApp
} else {
    LIBS += -L"C:/Program Files (x86)/Windows Kits/10/Lib/10.0.16299.0/um/x86" -lWindowsApp
}

[Chris Kawa]

Sorry, it seems I jumped the gun on the info about C++/WinRT being part of Windows SDK already. According to the author it's currently in the preview versions and will be part of the future official releases. I got confused because there's a winrt directory with all the headers in the SDK, but that's for C++/cx. C++/WinRT will be placed in cppwinrt directory.

So for now you need to download C++/WinRT separately from https://github.com/Microsoft/cppwinrt.
Apparently it's also not entirely header-only so you do need to add windowsapp to the linker.
Last thing is that the library uses C++17 so you'll need to enable that in the compiler.

So here's an example I got to work that lists all the devices on your pc.
In your .pro file add these:

INCLUDEPATH += <wherever you downloaded the winrt library from github>
QMAKE_CXXFLAGS += /std:c++17
LIBS += -lwindowsapp

And the main.cpp looks like this:

#include <QString>
#include <QDebug>
#include "winrt/Windows.Devices.Enumeration.h"

using namespace winrt;
using namespace winrt::Windows::Devices::Enumeration;

int main()
{
    init_apartment(); //this initializes com

    DeviceInformationCollection infos = DeviceInformation::FindAllAsync().get();

    for (const auto& info : infos)
        qDebug() << QString::fromWCharArray(info.Name().c_str());
}

UWP libraries are highly asynchronous so if you'd like to use some of those async features you will also have to add the /await compiler flag to enable coroutine support in the compiler.

[Cobra91151]

@Chris-Kawa
What do you mean: INCLUDEPATH += <wherever you downloaded the winrt library from github>? There are only header files (in the .../cppwinrt-master/10.0.16299.0/winrt) directory. I have downloaded it from the link:
https://github.com/Microsoft/cppwinrt . Thanks.

.pro:

QMAKE_CXXFLAGS += /std:c++17
INCLUDEPATH += "C:/Users/cobra/Downloads/cppwinrt-master/10.0.16299.0"
LIBS += -lwindowsapp

.h

#include "winrt/windows.devices.enumeration.h"
using namespace winrt;
using namespace winrt::Windows::Devices::Enumeration;

.cpp

init_apartment(); //this initializes com
DeviceInformationCollection infos = DeviceInformation::FindAllAsync().get();

 for (const auto &info : infos) {
        qDebug() << QString::fromWCharArray(info.Name().c_str());
 }

It throws a lot of errors:

[Cobra91151]

I have checked it and all errors are from cppwinrt directory where the header files located.

I think something are overriding the cppwinrt header files or I use the wrong library. But Qt highlights the code so I am on the right direction. Thank you.

[Cobra91151]

@Chris-Kawa

I have found why these errors occurs. The problem is with the Qt Kits. I have 3 Qt UWP kits installed:

1. Qt 5.9.3 for UWP x32
2. Qt 5.9.3 for UWP x64
3. Qt 5.9.3 for UWP armv7

So when I'm trying to build for x32 or x64 UWP binaries, it throws the errors. But when I set armv7 kit as build target then no errors found and build succeeds. So the question is how to target x32/x64 UWP? Thanks.

[Cobra91151]

Can anyone confirm that Qt 5.9.3 UWP x32/x64 kits work with UWP API? Thanks in advance.