当您 addRect ... 然后 addLine ... 到 QGraphicsScene 时，您会期望在矩形上绘制线条，对吗？在 Qt 4.4.3，mac ppc 10.4.11 中，有些行没有，在下面的测试用例中。我想这是一个 Qt / mac lib / 显卡交互（版本炎疾病），所以任何能说“它在......中很干净”的人都会很感激。
谢谢，加油
// QGraphicsScene mac rendering bug: some addLines are hidden by previous addRects
// C: 150 line is hidden under most rects, others ok
// pyqt: other lines are hidden
// qt-mac-opensource-src-4.4.3 PyQt-mac-gpl-4.4.4 macosx 10.4.11, ppc, GEForce2 mx
// denis-bz-gg@t-online.de 9jun
#include <cmath>
#include <QtGui>
int main( int argc, char* argv[] )
{
qDebug() << "qVersion:" << qVersion();
QApplication app( argc, argv );
int Size = 10; // changes what's hidden
int x0 = -500, y0 = -500, x1 = 500, y1 = 500;
QRectF scenerect( x0, y0, x1, y1 );
QGraphicsScene* scene = new QGraphicsScene( scenerect );
QGraphicsView* view = new QGraphicsView( scene );
view->centerOn( 100, 100 ); // ?
for( int j = x0/2; j < x1/2; j += Size ){
for( int k = y0/2; k < y1/2; k += Size ){
scene->addRect( j, k, Size-1, Size-1, Qt::NoPen, QBrush( "palegreen" ));
}
}
for( int angle = 0; angle < 180; angle += 30 ){
float c = cos( angle * M_PI / 180 ) * x1;
float s = sin( angle * M_PI / 180 ) * y1;
scene->addLine( -c, -s, c, s, QPen( "black" ));
}
view->show();
return app.exec();
}