我使用QSGGeometry、QSGVertexColorMaterial和QSGGeometryNode在我的QQuickItem派生类上实时绘制一些东西这是MyQuickItem这里。以下是我的updatePaintNode方法，重绘逻辑的症结所在。QSGNode*MyQuickItem::updatePaintNode(QSGNode*oldNode,UpdatePaintNodeData*updatePaintNodeData){if(!oldNode){oldNode=newQSGNode;}oldNode->removeAllChildNodes();QSGGeometry