@JPolo said in Unable to compile when using QCustomPlot:

I use Qt Creator 4.15.0 based on Qt 5.15.2 MSVC2019

That is not necesserilly Qt version you're using (this is the Qt version used to build QtCreator).
What Qt version did you install?

What is the first error message?
Did you do what the tutorial suggests: "To use the shared library in your application, set the define QCUSTOMPLOT_USE_LIBRARY before including the QCustomPlot header."?

@VRonin

Great answer !, especially to be adapted to my needs. Anyway, I think I should try with Format_Indexed8 instead as I need to store the color values which requires more than a single bit:

0 : off
1 : Green
2 : Red
3 : Orange

(Merci pour cette réponse)