未知的 CMake Qt5 命令

Question

我目前正在尝试使用 CMake 构建一个项目。这是我得到的输出

CMake Warning at ext/quazip/CMakeLists.txt:4 (FIND_PACKAGE):
  By not providing "FindQt5.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "Qt5", but
  CMake did not find one.
  Could not find a package configuration file provided by "Qt5" with any of
  the following names:
    Qt5Config.cmake
    qt5-config.cmake
  Add the installation prefix of "Qt5" to CMAKE_PREFIX_PATH or set "Qt5_DIR"
  to a directory containing one of the above files.  If "Qt5" provides a
  separate development package or SDK, be sure it has been installed.

CMake Error at ext/quazip/CMakeLists.txt:19 (qt5_wrap_cpp):
  Unknown CMake command "qt5_wrap_cpp".

我安装了Qt Creator，但我不确定为什么会出现此错误。我在网上环顾四周，他们说我应该添加

set(QT_USE_QTXML true)
FIND_PACKAGE(Qt5)

在 ext/quazip/CMakeList 中的 #project 之后.txt我已经这样做了，但是我仍然收到此错误的任何建议？

更新：因此，我将以下内容添加到我的顶级CMakeLists中.txt

find_package( Qt5Core REQUIRED )
find_package( Qt5Widgets REQUIRED )
find_package( Qt5Gui REQUIRED )
find_package( Qt5OpenGL REQUIRED )
find_package( Qt5Multimedia REQUIRED )
find_package( Qt5WebKitWidgets REQUIRED )
find_package( Qt5Xml REQUIRED )

我清除了缓存，然后进行了配置。在这一点上，我收到以下错误。

CMake Error at CMakeLists.txt:3 (find_package):
  By not providing "FindQt5Core.cmake" in CMAKE_MODULE_PATH this project has
  asked CMake to find a package configuration file provided by "Qt5Core", but
  CMake did not find one.
  Could not find a package configuration file provided by "Qt5Core" with any
  of the following names:
    Qt5CoreConfig.cmake
    qt5core-config.cmake
  Add the installation prefix of "Qt5Core" to CMAKE_PREFIX_PATH or set
  "Qt5Core_DIR" to a directory containing one of the above files.  If
  "Qt5Core" provides a separate development package or SDK, be sure it has
  been installed.

Configuring incomplete, errors occurred!

Answer 1

要在 CMakeList 中使用Qt5.txt您应该使用这些函数（组合）：

在顶级CMakeLists中.txt

#### Qt5
find_package( Qt5Core REQUIRED )
find_package( Qt5Widgets REQUIRED )
find_package( Qt5Gui REQUIRED )
find_package( Qt5OpenGL REQUIRED )
find_package( Qt5Multimedia REQUIRED )
find_package( Qt5WebKitWidgets REQUIRED )
find_package( Qt5Xml REQUIRED )
set( CMAKE_AUTOMOC ON )  # to automoc remove the need to wrap by hand

编辑：Qt5 cmake 模块由 Qt5 本身提供，所以你需要告诉 cmake 在哪里可以找到 qt。请参阅Qt5 CMake文档。

Answer 2

最后，通过一些搜索，我能够得到CANDevStudio——它也有这个Qt5问题——通过以下方式在Ubuntu 20.04上工作：

步骤1：从他们的网站手动下载并安装Qt（需要免费创建帐户）：https://download.qt.io/archive/qt/

根据：本网站，可能需要删除任何其他版本的libqt5：

sudo apt purge libqt5svg5-def
sudo apt purge libqt5serialbus5-dev

第 2 步：将 DCMAKE_PREFIX_PATH 标志设置为新安装软件的目录构建软件（在我的情况下，我将其放在我的主目录中）：

cmake .. -DCMAKE_PREFIX_PATH=/home/<username>/Qt5.12.0/5.12.0/gcc_64

来源：CanDevStudio的帮助页面