[Windows10] - Failed to extract plugin meta data from .....

[giladreich]

Failed to extract plugin meta data from 'C:\Qt\Qt5.8.0\5.8\msvc2015_64\plugins\designer\ColorWidgets-qt51.dll'

I'm trying to use this plugin, but getting this error when i go to Help -> About Plugins -> Failed Plugins
The Widgets won't display in the designer.
Note that I'm using Qt Version: 5.8.
I build the plugin in release mode from the Qt Creator.
Then i also tried building with cmake with a different bundle of Qt of MinGW32 with these commands:

mkdir build
cd build
cmake ..
cmake-make
cmake-make install
And then confirmed that i have the dll in that path:
C:\Qt\Qt5.8.0\5.8\msvc2015_64\plugins\designer\ColorWidgets-qt51.dll

Is that has to do with compatibility issues with Windows? or I'm doing something wrong?

[mbasaglia]

Are you sure you are installing the right library? it should be called ColorWidgetsPlugin, while the one shown in the Qt Designer is just ColorWidgets (which is the library you should link to in the actual project).

[giladreich]

@mbasaglia Pretty positive, I downloaded the sourcecode -> opened with Qt Creator -> run qmake -> build all -> then the only thing i get is ColorWidgets-qt51.dll and libColorWidgets-qt51.a, i tried putting libColorWidgets-qt51.a in lib and dll in plugins.
I tried building in release and debug mode and i don't see any ColorWidgetsPlugin.

[Kicer86]

@mbasaglia @giladre looking at code I can see there is nothing about exporting symbols which is crucial when building under windows (for sure for visual studio, not sure about mingw, it may export everything by default). I think #23 and #17 suffer from the same thing.

[mbasaglia]

@Kicer86 https://github.com/mbasaglia/Qt-Color-Widgets/blob/master/include/colorwidgets_global.hpp

[Kicer86]

@mbasaglia I cannot see usage in qt-designer plugin code

[mbasaglia]

Does it work if you add them to the plugin code?

[Kicer86]

@mbasaglia don't know, I'm pure linux user, I just try to help :)

[mbasaglia]

shrugs I have no way to test it myself so it can't really be fixed until someone who has windows can test this.

[Kicer86]

@mbasaglia you may try to build sources with -fvisibility=hidden and -fvisibility-inlines-hidden and adopt export macros you showed me to expand to attribute ((visibility ("default"))) for gcc. This should emulate windows situation. More details here.

[kevin-ur]

you can create custom widget from gui ,here is for your reference