想要利用QT畫一個雷達圖，撰寫了如下的程式：
void RadarDlg::paintEvent( QPaintEvent * )
{
QPainter *painter = new QPainter(this);
painter->setRenderHint(QPainter::Antialiasing);
painter->setRenderHint(QPainter::SmoothPixmapTransform);
painter->setRenderHint(QPainter::TextAntialiasing);
drawRadarType(painter);
drawLabel(painter);
drawData(painter);
drawAxisLabel(painter);
}
但是運行時，會報警告：
QBackingStore::endPaint() called with active painter on backingstore paint device
QPaintDevice: Cannot destroy paint device that is being painted
然后給paintEvent加上begin()和end()
void CRadarDlg::paintEvent( QPaintEvent * )
{
QPainter *painter = new QPainter(this);
painter->begin (this);
painter->setRenderHint(QPainter::Antialiasing);
painter->setRenderHint(QPainter::SmoothPixmapTransform);
painter->setRenderHint(QPainter::TextAntialiasing);
drawRadarType(painter);
drawLabel(painter);
drawData(painter);
drawAxisLabel(painter);
painter->end ();
}
還是有警告：
QPainter::begin: Painter already active
請問該如何讓解決？
uj5u.com熱心網友回復：
試一下delete painter；painter=NULL；uj5u.com熱心網友回復：
試了一下，還是不行。
uj5u.com熱心網友回復：
QPainter* p = new QPainter;
p->begin(this);
p->setBrush(QBrush(QColor(222,222,123)));
p->drawRect(0,0,10,20);
p->end();
delete p;
p=NULL;
uj5u.com熱心網友回復：
這個不管用呀？樓主最后怎么解決的呢？求賜教。轉載請註明出處，本文鏈接：https://www.uj5u.com/houduan/17580.html
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