构建 QML 应用程序

在 构建 C++ 控制台应用程序 we showed the CMakeLists.txt file for a simple console application. We will now create a QML application that uses the Qt Quick 模块。

This is the full project file:

cmake_minimum_required(VERSION 3.16)
project(hello VERSION 1.0 LANGUAGES CXX)
find_package(Qt6 6.2 COMPONENTS Quick Gui REQUIRED)
qt_standard_project_setup(REQUIRES 6.5)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
qt_add_executable(myapp
    main.cpp
)
qt_add_qml_module(myapp
    URI hello
    QML_FILES
        main.qml
        FramedImage.qml
    RESOURCES
        img/world.png
)
target_link_libraries(myapp PRIVATE Qt6::Gui Qt6::Quick)
					

Let's walk through the changes we have made. In the find_package call, we replace 核心 with Quick 。这会定位 Qt6Quick module and provide the Qt6::Quick targets we later link against.

find_package(Qt6 6.2 COMPONENTS Quick Gui REQUIRED)
					

调用 qt_standard_project_setup , and specify CMAKE_CXX_STANDARD ，和 CMAKE_CXX_STANDARD_REQUIRED . By passing REQUIRES 6.5 to qt_standard_project_setup , we opt-in to useful defaults for qt_add_qml_module . It enables all the Qt CMake policies up to version 6.5, in particular QTP0001 that defines a sane default resource prefix for QML modules.

qt_standard_project_setup(REQUIRES 6.5)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
					

注意，应用程序仍会链接 Qt6::Core ，因为 Qt6::Quick depends on it.

qt_add_executable creates and finalizes an application target:

qt_add_executable(myapp
    main.cpp
)
					

qt_add_qml_module passes the target of the executable, a URI, module version, and a list of QML files to ensure that myapp becomes a QML module. This places the QML files into qrc:/qt/qml/${URI} in the resource file system. Moreover, qt_add_qml_module ensures that qmlcachegen runs. Additionally, it creates a myapp_qmllint target, which runs qmllint on the files in QML_FILES.

qt_add_qml_module(myapp
    URI hello
    QML_FILES
        main.qml
        FramedImage.qml
    RESOURCES
        img/world.png
)
					

By adding the referenced resources, they get automatically added to the application under the same root path as the QML files – also in the resource file system. By keeping the path in the resource system consistent with the one in the source and build directory, we ensure that the image is always found, as it is resolved relative to FramedImage.qml. It refers to the image in the resource file system if we load main.qml from there, or to the one in the actual file system if we review it with the qml 工具。

在 target_link_libraries command, we link against Qt6::Quick 而不是 Qt6::Core .

target_link_libraries(myapp PRIVATE Qt6::Gui Qt6::Quick)
					

CMake 快速入门 构建可重用 QML 模块