Cmake Qt5 |未定义对`QPrinter :: QPrinter（QPrinter :: PrinterMode）的引用 [英] Cmake Qt5 | undefined reference to `QPrinter::QPrinter(QPrinter::PrinterMode)

问题描述

我正在为qt应用程序准备cmake构建。我在使用以下结构..

I am preparing cmake build for qt application. where I am using following structure ..

libMyApp
使用

libMyApp which uses

SET(QT5_MODULES Widgets PrintSupport Network XmlPatterns)
FIND_PACKAGE(Qt5 REQUIRED COMPONENTS ${QT5_MODULES})

和

TARGET_LINK_LIBRARIES(
    ${TARGET_NAME}
    Qt5::Widgets
    Qt5::PrintSupport 
    Qt5::Network
    Qt5::XmlPatterns
)

libMyApp构建成功并生成libMyApp.a（静态库）

libMyApp build successfully and generated libMyApp.a (static library)

现在我正在我的应用程序MyApp
中使用该库，该库使用

Now I am using this library in my application MyApp which uses

SET(QT5_MODULES Widgets PrintSupport XmlPatterns)
FIND_PACKAGE(Qt5 REQUIRED COMPONENTS ${QT5_MODULES})

TARGET_LINK_LIBRARIES(
    ${TARGET_NAME}
    Qt5::Widgets
    Qt5::PrintSupport 
    Qt5::XmlPatterns
    ${CODE_LIB_FILES}
)

$ {CODE_LIB_FILES}在列表中libMyApp.a的引导路径$ a $ b MyApp成功构建，最后显示链接错误

${CODE_LIB_FILES} is list holding path of libMyApp.a MyApp builds successfully and at last shows linking error

undefined reference to `QPrinter::QPrinter(QPrinter::PrinterMode)

xml也发生了同样的事情

Same thing happening with xml also

undefined reference to `QDomNode::isElement() const'

任何人都可以指出这里出了什么问题吗？

can anyone point out what is wrong here ?

或任何使用printsupport和xmlpatterns模块描述相同场景的示例程序

or any sample program depicting same scenario with printsupport and xmlpatterns module

推荐答案

函数 TARGET_LINK_LIBRARIES（）中的条目顺序很重要。最后要提到没有依赖关系的库，它们通常是一些标准库或外部库，在此示例中是Qt5库。

The order of the entries in the function TARGET_LINK_LIBRARIES() is important. The libraries with no dependecies shall be mentioned last which are typically some standard libraries or external libraries, in this example the Qt5 Libs.

示例：

• 取决于应用程序


• Lib_A 取决于 Lib_B 和 Lib_std


• Lib_B 取决于在 Lib_std


• Lib_std 没有依赖项

• Application depends
• Lib_A depends on Lib_B and Lib_std
• Lib_B depends on Lib_std
• Lib_std has no dependencies

然后调用该函数：

TARGET_LINK_LIBRARIES(
    ${TARGET_NAME}   # Name of the app
    "Lib_A"
    "Lib_B"
    "Lib_std"        # Last entries: Std Libs, external Libs, ...
)

在此应用程序中，我假设 $ {CODE_LIB_FILES} = libMyApp.a 与Qt5-Lib有一些依赖关系，因此可以将此项移至Qt5-Lib之上。

In this application I assumed that ${CODE_LIB_FILES}=libMyApp.a has some dependencies to the Qt5-Libs so it would be plausible to move this entry above the Qt5-Libs.

SET(QT5_MODULES Widgets PrintSupport XmlPatterns)
FIND_PACKAGE(Qt5 REQUIRED COMPONENTS ${QT5_MODULES})

TARGET_LINK_LIBRARIES(
    ${TARGET_NAME}
    ${CODE_LIB_FILES}       # <<< Moved this entry up
    Qt5::Widgets
    Qt5::PrintSupport 
    Qt5::XmlPatterns
)

这篇关于Cmake Qt5 |未定义对`QPrinter :: QPrinter（QPrinter :: PrinterMode）的引用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！