Can't include <QtCharts/QLineSeries>

问题

It seems I can't find a way to include <QtCharts/QLineSeries> in my header so Qt knows about the QLineSeries class.

• I added Qt += charts to my .pro file.
• I added #include <QtCharts/QLineSeries> to MainWindow.h
• Then I delete .pro.user file and any builds I've done. And then reopen the .pro file to reconfigure the project in the cleanest way.
• Finally I set the build mode to Release, run QMake by right-clicking the project and selecting it and Run it.

I get the message:

 ...\PlottingCharts\mainwindow.h:14: error: 'QLineSeries' does not name a type
     QLineSeries *series;
     ^

So clearly Qt doesn't know anything about QLineSeries.

For reference, the linechart and openglseries examples work correctly.

Any one knows what I'm missing?

回答1:

As I wrote the question I found the answer.

I was missing using namespace QtCharts; in the header file. Got the reference from: http://doc.qt.io/qt-5/qtcharts-index.html

回答2:

If you want to avoid specifying the namespace, you can also declare your variable as:

QtCharts::QLineSeries *series;

With this solution you always have to prepend QtCharts::, but you also know your scope and the origin of your calls.

来源：https://stackoverflow.com/questions/38802982/cant-include-qtcharts-qlineseries