qt - 将cmake项目与Qt5链接时部署icu库

我使用以下CMakeLists.txt创建一个小应用程序：

cmake_minimum_required (VERSION 3.5.0)

project (sampleapp)

# Setting project flags
set (CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/build/lib)
set (CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/build/lib)
set (CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/build/bin)
set (CMAKE_INCLUDE_CURRENT_DIR ON)
set (CMAKE_AUTOMOC ON)

# Finding needed packages
find_package (Qt5Widgets REQUIRED)
find_package (Qt5Core REQUIRED)
find_package (Qt5Gui REQUIRED)

# Setting project files
include_directories (${CMAKE_SOURCE_DIR}/src ${CMAKE_CURRENT_SOURCE_DIR})
file (GLOB_RECURSE PROJECT_SRC *.cpp)

# Creating project
add_executable(${PROJECT_NAME} ${PROJECT_SRC})

# Linking dependencies
target_link_libraries (${PROJECT_NAME} somelibrary Qt5::Widgets Qt5::Gui Qt5::Core)
add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD COMMAND ${CMAKE_COMMAND} -E copy_if_different $<TARGET_FILE:Qt5::Widgets> $<TARGET_FILE_DIR:${PROJECT_NAME}>)
add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD COMMAND ${CMAKE_COMMAND} -E copy_if_different $<TARGET_FILE:Qt5::Gui> $<TARGET_FILE_DIR:${PROJECT_NAME}>)
add_custom_command(TARGET ${PROJECT_NAME} POST_BUILD COMMAND ${CMAKE_COMMAND} -E copy_if_different $<TARGET_FILE:Qt5::Core> $<TARGET_FILE_DIR:${PROJECT_NAME}>)

当我运行它，然后构建应用程序时，会将Qt dll复制到目标文件夹中。我特别复制：


Qt5Core.dll
Qt5Gui.dll
Qt5Widgets.dll


当我运行该应用程序时，它仍然无法启动，因为Qt所需的ICU库没有被复制。当我启动应用程序时，Windows告诉我缺少以下库：


icuin53.dll
icuuc53.dll


如果我从Qt的insallation文件夹中手动复制这些库，则它可以正常工作（好的，关于“平台插件窗口”的错误，这是另一个错误）。

有没有一种以标准方式复制icu库的方法，例如我用于复制库的post build命令？或者，如果可能的话，以透明方式复制它们的最佳方法是什么（CMake可以知道Qt的依赖项是什么，并在需要Qt的地方复制它们）？

最佳答案

无需手动复制每个dll，您可以使用Qt附带的用于安装在Windows上的工具windeployqt安装所有Qt依赖项。

您可以首先将windeployqt声明为导入的可执行文件：

find_package(Qt5
    # ...
)

if(Qt5_FOUND AND WIN32 AND TARGET Qt5::qmake AND NOT TARGET Qt5::windeployqt)
    get_target_property(_qt5_qmake_location
        Qt5::qmake IMPORTED_LOCATION
    )

    execute_process(
        COMMAND "${_qt5_qmake_location}" -query QT_INSTALL_PREFIX
        RESULT_VARIABLE return_code
        OUTPUT_VARIABLE qt5_install_prefix
        OUTPUT_STRIP_TRAILING_WHITESPACE
    )

    set(imported_location "${qt5_install_prefix}/bin/windeployqt.exe")

    if(EXISTS ${imported_location})
        add_executable(Qt5::windeployqt IMPORTED)

        set_target_properties(Qt5::windeployqt PROPERTIES
            IMPORTED_LOCATION ${imported_location}
        )
    endif()
endif()

现在，可以按以下方式使用导入的可执行文件：

add_executable(foo
    # ...
)

if(TARGET Qt5::windeployqt)
    add_custom_command(TARGET foo
        POST_BUILD
        COMMAND ${CMAKE_COMMAND} -E remove_directory "${CMAKE_CURRENT_BINARY_DIR}/windeployqt"
        COMMAND set PATH=%PATH%$<SEMICOLON>${qt5_install_prefix}/bin
        COMMAND Qt5::windeployqt --dir "${CMAKE_CURRENT_BINARY_DIR}/windeployqt" "$<TARGET_FILE:foo>"
    )

    install(
        DIRECTORY
        "${CMAKE_CURRENT_BINARY_DIR}/windeployqt/"
        DESTINATION ${FOO_INSTALL_RUNTIME_DESTINATION}
    )
endif()