QT environment cannot run error set

One 、 The lack of qt platform Dependency Library ;

qt.qpa.plugin: Could not find the Qt platform plugin "windows" in ""
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Less platform dll library , Such as windows platform

take similar Your path D:\ProgramData\Qt\5.12.4\msvc2017_64\plugins\platforms

copy to Running directory ; In fact, it uses qwindows.dll or qwindowsd.dll

Two 、 The lack of qt sqldrive Dependency Library

WARNING: QSqlDatabase: QSQLITE driver not loaded

Less sqldrive

take similar Your path D:\ProgramData\Qt\5.12.4\msvc2017_64\plugins\sqldrivers

copy to Running directory ;

The above two can also be passed cmake Realization

Specify a set of custom plug-ins to import （ Be careful ： This macro is only from static Qt Build import plug-ins . On the shared version , Invalid .）

qt5_import_plugins(target
                   [INCLUDE plugin ...]
                   [EXCLUDE plugin ...]
                   [INCLUDE_BY_TYPE plugin_type plugin ...]
                   [EXCLUDE_BY_TYPE plugin_type])

 Specify a set of custom plug-ins to import . Optional parameters ：INCLUDE,EXCLUDE,INCLUDE_BY_TYPE, and EXCLUDE_BY_TYPE, Multiple use .

 this CMake Command in Qt 5.14 Introduction in .

    INCLUDE - Can be used to specify the list of plug-ins to import .
    EXCLUDE - Can be used to specify the list of plug-ins to exclude .
    INCLUDE_BY_TYPE - Can be used to override the list of plug-ins to import for a specific plug-in type .
    EXCLUDE_BY_TYPE- Can be used to specify the plug-in type to exclude ; Then this type of plug-in will not be imported .

Qt Provide plug-in types , for example imageformats,platforms, and sqldrivers.

 If qt5_import_plugins() Not invoked , Then the target will automatically link to a set of default plug-ins , For each Qt modular . For more information , Please see the target_link_libraries.

 Each plug-in comes with a C ++ Stub file , This file will automatically initialize the plug-in . therefore , Any target linked to the plug-in will put this C ++ Add file to it SOURCES.

 Be careful ： This macro is only from static Qt Build import plug-ins . On the shared version , Invalid .

 Example 

add_executable(myapp main.cpp)
target_link_libraries(myapp Qt5::Gui Qt5::Sql)
qt5_import_plugins(myapp
    INCLUDE Qt5::QCocoaIntegrationPlugin
    EXCLUDE Qt5::QMinimalIntegrationPlugin
    INCLUDE_BY_TYPE imageformats Qt5::QGifPlugin Qt5::QJpegPlugin
    EXCLUDE_BY_TYPE sqldrivers
)

 In the code snippet above , Execution procedure myapp The following happened :

     take Qt5::QCocoaIntegrationPlugin Import to myapp in .
     The Qt5::QMinimalIntegrationPlugin Plug ins are not automatically imported into myapp in .
     The default plug-in list imageformats Covered to include only Qt5 :: QGifPlugin and Qt5 :: QJpegPlugin.
     all sqldrivers Plug ins will not be automatically imported .

3、 ... and 、windows platform , The lack of VC Runtime

You can download this installation

VisualC++AIOv2019.05.21-C++ Document resources -CSDN download

Four 、 could not be loaded: Cannot load library Prompt missing dependent Library

could not be loaded: Cannot load library If you compile the library yourself, it cannot be loaded , Less dependence , It is still necessary to check ;

For example, it indicates that the file name is missing , You can find the corresponding dependent library according to the directory and copy it ;

windows The platform can be accessed through log and depends.exe Check it out ;

linux The platform can check dependencies through the command line

1. View dependent Libraries : objdump -x xxx.so | grep NEEDED

2. View the libraries that the executable depends on : objdump -x Executable name | grep NEEDED

3. View missing Libraries : ldd xxx.so

There are two solutions to the lack of inventory

1, Add to environment variables , If the folder is suitable for this method ;

2, Copy directly to the current directory ;

Another situation is that the directory of the current library is wrong , Move to the appropriate folder , This folder contains the libraries it depends on ,

But you cannot copy the library it depends on , Otherwise, there will be two , There will be problems ;

Summary

In short, specific issues , Specific analysis is also needed , Constantly encounter problems , Can't solve the problem , Growing up ;