Qt update（）不工作

本文介绍了Qt update（）不工作的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ 我有一个问题，在 QGraphicsItem 中的update（）函数不工作。我想做的是，当我移动圆，其他 QGraphicsItem （在平均时间roundrect）改变颜色。 这是一个例子，我想做什么：I have a problem , that update() function in QGraphicsItem doesn't work. What I want to do is , when I move circle , other QGraphicsItem( in the mean time roundrect ) changes color.This is a example, what I want to do: circle.cpp：circle.cpp:void CircleItem::mouseMoveEvent(QGraphicsSceneMouseEvent *event){ // RoundRect Object RectItem->SetBackGround(); QGraphicsItem::mouseMoveEvent( event );} RoundRect.cpp：RoundRect.cpp:void RoundRectItem::SetBackGround(){ ChangeBackground = true; update();}void RoundRectItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget){ QRectF rec = QRectF( QPoint( 0,0 ), boundingRect().size() / 2 ); roundRect = QRectF(rec.adjusted(-rec.height() / 2, 0, rec.height()/2, 0)); roundRect.moveTo( boundingRect().center().x() - roundRect.width() / 2, boundingRect().center().y() - roundRect.height() / 2 ); if( !ChangeBackground ) painter->setBrush( backBrush ); else painter->setBrush( QBrush( Qt::blue ) ); painter->setPen( QColor( 255,255,255 ) ); painter->drawRoundedRect(roundRect, roundRect.height() / 2, roundRect.height() / 2 );} $ bSo the question is, how can I make this update() work right.推荐答案正在调用QGraphicsItem的update（）方法。你应该调用你正在使用的QGraphicsView的update（）。例如，你可以保持你的QGraphicsView作为你的项目的成员类，如：You are invoking the update() method of QGraphicsItem. You should call the update() of the QGraphicsView you are working with. For example you can keep your QGraphicsView as a member class of your item like:QGraphicsView * parent;当您希望更改发生时调用它的更新方法：And call it's update method when you want the changes take place like:void RoundRectItem::SetBackGround(){ ChangeBackground = true; parent->update();} 这篇关于Qt update（）不工作的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！