在子窗口中画图
各位老师,我想实现一个单击按钮然后在一个作为子控件的widget里画图的功能,查了一些资料使用了eventfilter的方法,程序如下:
widget.h
#ifndef WIDGET_H
#define WIDGET_H
#include <QWidget>
namespace Ui {
class Widget;
}
class Widget : public QWidget
{
Q_OBJECT
public:
explicit Widget(QWidget *parent = 0);
~Widget();
//virtual void changeEvent(QEvent *e);
virtual bool eventFilter(QObject *watched, QEvent *e);
void paintOnWidget(QWidget *w);
private slots:
void on_pushButton_clicked();
private:
Ui::Widget *ui;
};
#endif // WIDGET_H
widget.cpp
#include "widget.h"
#include "ui_widget.h"
#include <QtGui>
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this);
ui->widget->installEventFilter(this);
}
Widget::~Widget()
{
delete ui;
}
/*
void Widget::changeEvent(QEvent *e) {
QWidget::changeEvent(e);
switch (e->type()) {
case QEvent::LanguageChange:
ui->retranslateUi(this);
break;
default:
break;
}
}
*/
bool Widget::eventFilter(QObject *watched, QEvent *e) {
if (watched == ui->widget) {
if (e->type() == QEvent::Paint) {
paintOnWidget(ui->widget);
return true;
}
}
return QWidget::eventFilter(watched, e);
}
void Widget::paintOnWidget(QWidget *w) {
QPainter painter(w);
QPen pen; //画笔
pen.setColor(QColor(255, 0, 0));
QBrush brush(QColor(0, 255, 0, 125)); //画刷
painter.setPen(pen); //添加画笔
painter.setBrush(brush); //添加画刷
painter.drawRect(50, 50, 200, 100); //绘制矩形
}
void Widget::on_pushButton_clicked()
{
}
可以实现在widget里画图了,但是一把ui->widget->installEventFilter(this)写到on_pushButton_clicked()槽里就不能画出图了,请问有人能帮助修改一下吗?