我正在使用Qt 5.11.1和Qt Creator创建一个项目。我的代码在我已重写的paintEvent函数中绘制了多个椭圆。但是由于paintEvent函数的工作方式,我在省略号下的按钮被删除了。我想要一个窗口,该窗口的顶部为椭圆形,底部为按钮。大致看起来像这样:
有没有办法做到这一点。现在,按钮已被删除,我只有省略号。如果有人可以引导我,我将非常高兴。
谢谢。
注意:我的椭圆为绿色,背景为黑色,但是我尝试通过将背景更改为白色或更改按钮的样式表来解决问题,
这是我的.h文件:
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private:
Ui::MainWindow *ui;
protected:
void paintEvent(QPaintEvent *e);
void setBackGroundColorToBlack();
};
#endif // MAINWINDOW_H
这是我的.cpp文件:
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QtGui>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
setBackGroundColorToBlack();
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::paintEvent(QPaintEvent *event) {
setUpdatesEnabled(false);
QPainter painterObj;
painterObj.begin(this);
painterObj.setPen(QPen(Qt::green, 2, Qt::SolidLine, Qt::RoundCap));
painterObj.drawEllipse(0, 0, 318, 390);//456
painterObj.drawEllipse(53, 65, 212, 260);//304
painterObj.drawEllipse(106, 130, 106, 130);//152
painterObj.end();
}
void MainWindow::setBackGroundColorToBlack() {
QPalette pal = palette();
// set black background
pal.setColor(QPalette::Background, Qt::black);
this->setAutoFillBackground(true); // This enables the qt to fill the background before the paint event.
this->setPalette(pal);
//update();
}
这就是我得到的:
我的ui文件是这样的:
答案 0 :(得分:0)
通常-不要使用QMainWindows
类。它适用于具有菜单,状态栏等的“大型”桌面应用程序。您所需要做的就是从QDialog
甚至只是QWidget
派生。而且您可以自己绘制背景,因此无需弄乱调色板。下面应该工作的最小示例。如果没有显示Bar
按钮,则您对目标的Qt损坏:默认平台样式不起作用。
// https://github.com/KubaO/stackoverflown/tree/master/questions/painted-with-children-51498155
// This project is compatible with Qt 4 and Qt 5
#include <QtGui>
#if QT_VERSION >= QT_VERSION_CHECK(5,0,0)
#include <QtWidgets>
#endif
QRectF scaled(const QRectF &rect, qreal scale) {
auto const center = rect.center();
auto const w = rect.width()*scale;
auto const h = rect.height()*scale;
return {center.x() - w/2.0, center.y() - h/2.0, w, h};
}
QRectF marginAdded(const QRectF &rect, qreal margin) {
return rect.adjusted(margin, margin, -margin, -margin);
}
const char buttonQSS[] =
"* { background-color: white; border-width: 2px; border-style:solid; border-color: red;"
" border-radius: 3px; padding: 3px; }"
"*:pressed { padding-left: 5px; padding-top: 5px; background-color: lightGray; }";
class MyWindow : public QWidget {
Q_OBJECT
QPushButton m_restoreButton{"Restore Size"};
QPushButton m_otherButton{"Bar"};
QGridLayout m_layout{this};
Q_SLOT void onRestore() { resize(sizeHint()); }
public:
explicit MyWindow(QWidget *parent = {}) : QWidget(parent) {
setAttribute(Qt::WA_OpaquePaintEvent);
m_layout.addItem(new QSpacerItem(0, 100, QSizePolicy::Minimum, QSizePolicy::MinimumExpanding), 0, 0);
m_layout.addWidget(&m_restoreButton, 1, 0);
m_layout.addWidget(&m_otherButton, 1, 1);
m_restoreButton.setStyleSheet(buttonQSS);
connect(&m_restoreButton, SIGNAL(clicked(bool)), SLOT(onRestore()));
}
protected:
void paintEvent(QPaintEvent *) override {
qreal const penWidth = 2.0;
// Cover the area above all the children
QRectF const area = marginAdded(QRect(0, 0, width(), childrenRect().top() - 10), penWidth);
QPainter p(this);
p.fillRect(rect(), Qt::black);
p.setPen({Qt::green, penWidth});
p.drawEllipse(scaled(area, 3./3.));
p.drawEllipse(scaled(area, 2./3.));
p.drawEllipse(scaled(area, 1./3.));
}
QSize sizeHint() const override { return {320, 568}; /* iPhone 5 */ }
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MyWindow w;
w.show();
return a.exec();
}
#include "main.moc"