Qt for WinRT | Qt 5.12

Qt 5.12 | Qt for WinRT

Qt 5.12.8 Reference Documentation

# Qt for WinRT

Qt for WinRT allows you to run Qt applications on devices supporting the Windows Store App APIs. This covers Modern UI applications on Windows 10, Windows 10 Mobile and Windows 10 IoT.

Microsoft introduced a new design paradigm with the Windows 8 Modern UI. A core part of this new approach is Windows Runtime (WinRT) that supports development using different programming languages, such as C++/CX (component extensions), C# VB.NET, or JavaScript. The Qt port uses the C++ capabilities. While WinRT supports the component extensions internally, they are not used inside Qt and you do not need to use them. WinRT applications run in a sandboxed environment for security reasons and support different architectures, such as ARM and x86.

## Supported Configurations

The following configurations are supported.

Platform Version | Architecture | Compiler | Build Environment
--- | --- | --- | ---
Universal Windows Platform 10 | `x86`, `x86_64`, and `armv7` | MSVC 2017, MSVC 2015 | Windows 10 Creators Update

Universal Windows Platforms include Windows 10, Windows 10 IoT devices, Xbox One, and HoloLens.

## Requirements

Development for Windows Runtime requires a Microsoft Windows development host. The minimum version supported is Windows 10.

Depending on your device target you will need the following tools provided by Microsoft to be installed:

Device Target | Environment
--- | ---
Windows 10 Mobile | Visual Studio 2015
Windows 10 Desktop | Visual Studio 2015
Windows 10 IoT | Visual Studio 2015
XBox One | Visual Studio 2015

If you are targeting a remote device, please follow all instructions by Visual Studio to set it up correctly.

## Getting Started

### Notes to Desktop Users

As WinRT applications run in a sandboxed environment, some restrictions should be taken into account when considering porting or writing cross-platform applications:

- The class QProcess is not implemented (indicated by the macro `QT_NO_PROCESS` being defined) as no subprocesses can be launched.
- Some paths returned by QStandardPaths::writableLocation() may be empty.
- A WinRT application may not do socket-based communication with another application running on the same host (as this would violate the sandboxing).
- Applications run in fullscreen mode only (see QStyleHints). On desktop, the screen size varies as the application is resized.
- There are no environment variables. Qt emulates the functionality by maintaining the values locally, so that qputenv() and related functions continue to work. All known variables influencing Qt can be set in source code.
- WinRT applications are UI applications by nature. This implies that console type applications will have a window created internally, which is always visible.
- Applications should not exit programmatically. In particular, calling exit() before the UI is shown causes a crash.
- The WinRT clipboard is local to the application; it cannot be retrieved by a desktop application.

### Building Applications

You can develop applications for WinRT just as any other Qt applications. Use your favorite editor or IDE (such as Qt Creator) and create your application or load a Qt example. Then run `qmake` and `nmake/jom` to build your application.

#### Building Applications with Visual Studio

To launch your project with Visual Studio a corresponding project needs to be created. `qmake` supports converting a `.pro` project into Visual Studio format by passing the parameters `-tp` vc.

      qmake -tp vc <your project>.pro

Be aware of using the correct match of `qmake` and Visual Studio. As the Visual Studio format is generic, it does not return an immediate error if for instance you open a Windows Phone project inside Visual Studio for Windows.

This creates a project which supports building applications and running them with Visual Studio. It does not embed Qt libraries into the package and requires you to add them manually. For this purpose, the command line tool windeployqt has been included in the installed package. To enable automatic parsing of dependencies and adding the libraries and dependencies into the application package, create the project with the following options:

      qmake -tp vc <your project>.pro "CONFIG+=windeployqt"

#### Building Applications with Qt Creator

You will not need to do any conversion to open your project in Qt Creator. Please follow the generic instructions on how to open and build a project.

Qt Creator deploys your application on the WinRT device, if the device is detected by the PC.

Note: Remote PCs, such as the Surface, are not yet supported for deployment by Creator.

## Building from Source

We assume that you have cloned the Qt 5 repositories (or obtained the Qt sources elsewhere) and followed the platform-independent requirements for building Qt. The process of building Qt is found in the Building Qt Sources page.

Qt for WinRT is always built as a cross-build, because tools, such as qmake, are built as desktop applications. For compiling those, a desktop development environment is required. If you have installed Visual Studio 2013 for Windows, this will only create binaries for WinRT. You will need Visual Studio for Windows Desktop as well to create those desktop tools.

Please make sure to use an x86 command prompt (either use the VS x86 Native Tools Command Prompt or call vcvarsall.bat without any parameter or with `x86`) for every WinRT build. While the toolchain which is used for the target is set automatically, the command prompt decides what will be used for the host tools like qmake or moc. Building these tools might fail if another command prompt is used.

The WinRT mkspec format is `<platform>-<architecture>-<toolchain>` where architecture can be `arm`, `x86`, or `x64`. The following is an example of building qtbase for WinRT:

      > ./configure -xplatform winrt-x64-msvc2013 -release
      > nmake/jom

## Running Applications from Command Line

WinRT applications must be packaged (including all dependencies) and installed or registered with the application service in order to be launched. The WinRT Runner Tool can be used to launch these applications from the command line.

### Package Content

Package content consists of the application executable and its dependencies, as for every Windows application. The dependencies are the needed (Qt) libraries and plugins. Note that Qt plugins have to be put into a folder named after their category (platforms, imageformats, and so on) without using a `plugins` folder as root. For more information, see Qt for Windows - Deployment.

As WinRT applications are run in a sandboxed environment, setting the path variable to point to the files required will not work.

The windeployqt convenience tool looks up the application's dependencies and copies Qt libraries and plugins to the appropriate directories, as necessary.

Because all resources are placed to one directory, you can register the directory using an XML file (AppxManifest.xml) and Windows Powershell. The reference for these manifest files can be found here. The target processor architecture must be specified (as opposed to the default, 'neutral'). As soon as these requirements are met, change into your packaged directory in PowerShell and call:

      > Add-AppxPackage -Register AppxManifest.xml

Note: The WinRT Runner Tool can perform the same operation with the --install option.

If that worked, you should be able to find your application in Windows' start screen. To remove your application, use Windows' built-in way to uninstall applications (right-click or tap and hold the application and choose `Uninstall`).

Note: The WinRT Runner Tool can perform the same operation with the --remove option.

### WinRT Runner Tool

The WinRT Runner Tool can be found in QTDIR/bin/winrtrunner. It is intended to aid in the deployment, launching, and debugging of Qt for WinRT applications. It can be used from the command line, or invoked by the IDE.

      Usage: winrtrunner [options] package [arguments]
      winrtrunner installs, runs, and collects test results for packages made with Qt.

      Options:
        --test                            Install, start, collect output, stop (if
                                          needed), and uninstall the package. This is
                                          the default action of winrtrunner.
        --start                           Start the package. The package is installed
                                          if it is not already installed. Pass
                                          --install to force reinstallation.
        --debug <debugger>                Start the package with the debugger
                                          attached. The package is installed if it is
                                          not already installed. Pass --install to
                                          force reinstallation.
        --debugger-arguments <arguments>  Arguments that are passed to the debugger
                                          when --debug is used. If no debugger was
                                          provided this option is ignored.
        --suspend                         Suspend a running package. When combined
                                          with --stop or --test, the app will be
                                          suspended before being terminated.
        --stop                            Terminate a running package. Can be be
                                          combined with --start and --suspend.
        --wait <seconds>                  If the package is running, waits the given
                                          number of seconds before continuing to the
                                          next task. Passing 0 causes the runner to
                                          wait indefinitely.
        --install                         (Re)installs the package.
        --remove                          Uninstalls the package.
        --device <name|index>             Specifies the device to target as a device
                                          name or index. Use --list-devices to find
                                          available devices. The default device is the
                                          first device found for the active run
                                          profile.
        --profile <name>                  Force a particular run profile.
        --list-devices                    List the available devices (for use with
                                          --device).
        --verbose <level>                 The verbosity level of the message output
                                          (0 - silent, 1 - info, 2 - debug). Defaults
                                          to 1.
        --ignore-errors                   Always exit with code 0, regardless of the
                                          error state.
        --loopbackexempt <mode>           Enables localhost communication for
                                          clients,servers or both. Adding this
                                          possibility for servers needs elevated
                                          rights and might ask for these in a
                                          dialog.Possible values: client, server,
                                          clientserver
        -?, -h, --help                    Displays this help.

      Arguments:
        package [arguments]               The executable or package manifest to act
                                          upon. Arguments after the package name will
                                          be passed to the application when it starts.