1、QPainterPath (組合路徑，路徑運動，貝塞爾曲線)void ComplicatedPathWidgetpaintEvent (QPaintEvent *) QPainter painter (this );painter . setRenderHint(QPainter : Antialiasing );QPainterPath path ;path.lineTo ( 100, 0);path.cubicTo (200, 0, 100, 50, 200, 100); / 貝塞爾曲線path.closeSubpath ();/畫一條線到路徑的第一個點，閉合路徑path . addRec

2、t (50, 50, 50, 50); / 加一個矩形QPainterPath path2 ;path2.addEllipse (80, 30, 50, 50);path=path . subtracted ( path2 ); / 扣掉圓painter.translate ( 20, 20);painter.setBrush ( Qt: lightGray );painter.drawPath ( path );painter.setBrush ( Qt: NoBrush );painter.drawRect ( path . boundingRect ();日 c C Paint,可以取得

3、讓物體沿著沿路徑運動QPainterPath:pointAtPercent(qreal t)是一個很有用的函數(shù)，t 的值為0,1.0路徑上任意一點的坐標，在動畫一節(jié)里會使用這個函數(shù)來實現(xiàn)動畫的插值函數(shù)，任意的路徑運動，這里沒有用 Qt的動畫框架實現(xiàn)了讓物體沿著任意的路徑運動#ifndef ANIMATIONALONGPATHWIDGET_H#define ANIMATIONALONGPATHWIDGET_H#include #include class AnimationAlongPathWidget : public QWidget Q_OBJECTpublic :explicit Anim

4、ationAlongPathWidget (QWidget * parent= 0);AnimationAlongPathWidget();protected :void timerEvent( QTimerEvent * event ) Q_DECL_OVERRIDEvoid paintEvent( QPaintEvent* event ) Q_DECL_OVERRIDEprivate :QPainterPath path ;float percent ;float step ;int timerld ;)；#endif / ANIMATIONALONGPATHWIDGET_H#includ

5、e AnimationAlongPathWidget.h#include#include#include AnimationAlongPathWidget : AnimationAlongPathWidget ( QWidget * parent ) : QWidget ( paren t) step = 0.02 ;percent = 0;/構造一個任意的曲線path.cubicTo(50,0, 30,100,100, 100);path.cubicTo(150,100 ,250,0, 200, 100);path.cubicTo(150,100 ,250,0, 300, 140);path

6、.quadTo ( 150,310, 150 ,100);/啟動定時器timerId = startTimer (60);)AnimationAlongPathWidget :AnimationAlongPathWidget () )void AnimationAlongPathWidget : timerEvent ( QTimerEvent * event ) /不停的更新percent 的值，刷新界面，實現(xiàn)動畫效果if (event - timerld () = timerld ) percent+= step ;if (percent 1) step= -step ; / 運動方向取反percent= qMin ( percent , 1.0F );percent= qMax ( percent , 0.0F );update ();void AnimationAlongPathWidget : paintEvent ( QPaintEvent *) QPainter painter (this );painter . setRenderHint (QPainter : Antialiasing );painter.translate(20, 20);p