在QWidget上绘图 [英] Draw on QWidget
问题描述
如何使用QWidget(窗体上的元素)?
我阅读了很多教程,但都没有涵盖我的实际知识必须做(在QWidget上绘制一些Rect)。
I read many tutorials but none of them covers what I really have to do(draw some Rect on QWidget) .
我制作了一个类MyFigure,它继承自QWidget,甚至paint编写了一些代码来绘制矩形。
然后,在我的Form Create中创建MyFigure对象,然后将其显示。
I made a class MyFigure which inherits from QWidget, and at even paint wrote some code to draw a rectangle. Then, in my Form Create I create MyFigure object, and just show it.
它不工作了!
推荐答案
QGraphicsView和QGraphicsScene非常适合绘画,但是如果要在QWidget上绘制,则需要重新实现paintEvent:
QGraphicsView and QGraphicsScene are good for painting, but if you want to draw on QWidget you need to reimplement paintEvent:
#include <QWidget>
#include <QPainter>
#include <QPaintEvent>
class Widget : public QWidget
{
public:
explicit Widget(QWidget *parent=0);
void paintEvent(QPaintEvent *event) Q_DECL_OVERRIDE;
};
Widget::Widget(QWidget *parent) : QWidget(parent)
{
}
void Widget::paintEvent(QPaintEvent *event)
{
QPainter painter;
painter.begin(this);
painter.fillRect(event->rect(), Qt::white);
QWidget::paintEvent(event);
painter.end();
}
此代码会用白色填充您的小部件。
This code will fill your widget with white color.
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