QPainter painter(this),this是指QPaintDevice或者他的子类，都可以！QFrame属于其子类范围，所以可以在其上面绘制！QHBoxLayout的addWidget（）参数可以只填写你绘制的那个widget类，另外两个参数有默认值！
QPainter painter(this); painter.drawArc(rectangle, startAngle, spanAngle); 1. 2. 3. 4. 5. 6. rectangle是绘制的区域; startAngle 、spanAngle是开始角度和结束角度,注意乘16,画圆就是360x16=5760 4、设置画笔 painter.setPen(QPen(Qt::blue,4,Qt::DashLine));//设置画笔形式 1. 5、设置画刷 pain...
出现QPainter::end: Painter ended whith 2 saced states 敬告,只需要在在绘制的结束的时候加上 restore() 函数就好了了
好像是必须在paint事件中声明使用.
ui->setupUi(this); } PainterDialog::~PainterDialog() { delete ui; } void PainterDialog::paintEvent(QPaintEvent *e) { QPainter painter(this); painter.setPen(Qt::blue); painter.setFont(QFont("Arial", 80)); painter.drawText(rect(), Qt::AlignCenter, "Qt"); ...
QPainter painter(this); 1. painter.setRenderHint(QPainter::Antialiasing); 1. painter.setRenderHint(QPainter::TextAntialiasing); 1. 1. qreal R=100; //qreal == double 1. const qreal pi = 3.14159; 1. qreal deg=pi*72/180; 1.