C++ Qt-drawRect在后台
我想绘制滑块的背景。我试过这个,但颜色掩盖了整个滑块。这是一个继承的QSlider类C++ Qt-drawRect在后台,c++,qt,paint,drawrect,qpainter,C++,Qt,Paint,Drawrect,Qpainter,我想绘制滑块的背景。我试过这个,但颜色掩盖了整个滑块。这是一个继承的QSlider类 void paintEvent(QPaintEvent *e) { QPainter painter(this); painter.begin(this); painter.setBrush(/*not important*/); // This covers up the control. How do I make it so the color is in // the backgr
void paintEvent(QPaintEvent *e) {
QPainter painter(this);
painter.begin(this);
painter.setBrush(/*not important*/);
// This covers up the control. How do I make it so the color is in
// the background and the control is still visible?
painter.drawRect(rect());
painter.end();
}
要设置小部件的背景,可以设置样式表:
theSlider->setStyleSheet("QSlider { background-color: green; }");
以下内容将设置小部件的背景,允许您执行更多操作:
void paintEvent(QPaintEvent *event) {
QPainter painter;
painter.begin(this);
painter.fillRect(rect(), /* brush, brush style or color */);
painter.end();
// This is very important if you don't want to handle _every_
// detail about painting this particular widget. Without this
// the control would just be red, if that was the brush used,
// for instance.
QSlider::paintEvent(event);
}
顺便说一句,下面两行示例代码将产生警告:
QPainter painter(this);
painter.begin(this);
也就是说,使用GCC:
QPainter::begin:一个绘画设备一次只能由一名画家绘制
一段时间
因此,请确保,正如我在示例中所做的那样,您要么执行
QPainter painter(this)
要么执行painter.begin(this)
您要做的是绘制小部件的背景?请说得具体一点。