Qt slot 或者 using Q_INVOKABLE 都可以被qml调用
public: ... Q_INVOKABLE void clearChart(); signals: void chartCleared();
qml中对应onChartCleared
Chapter 3: Adding Property Bindings
allows values of different elements to be synchronized automatically
让不同元素的值自动同步
The "color: chartA.color" statement binds the color value of chartB to the color of chartA
class PieChart : public QDeclarativeItem { ... Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY colorChanged) public: ... signals: void colorChanged(); ... };