qt 从 QChart 获取孩子（标注）

Question

I implemented a custom Callout class like in this example Callout Example

QPolarChart *chart = new QPolarChart();
Callout *callout = new Callout(chart);

If I have only access to chart (callout went out of scope), how can I regain access to callout. I thought about using

QObjectList children = chart->children();

but callout is not here. How can I get access to callout again?

Answer 1

you have to use childItems() , this returns the QGraphicsItem s children.

 for(QGraphicsItem *childItem: chart->childItems()){
     if(Callout *c = dynamic_cast<Callout *>(childItem)){
         //use c
     }
 }