关于本章节中使用的图形绘制类，如QGraphicsView、QGraphicsScene等的详细使用说明请参见我的另一篇文章：
《图形绘制QGraphicsView、QGraphicsScene、QGraphicsItem、Qt GUI-CSDN博客》
本文将模仿坦克大战游戏，目前只绘制出一辆坦克，并能发射炮弹
源代码下载地址：https://download.csdn.net/download/zhouhui1982/88784330
main.cpp文件中代码
#include <QApplication>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QGraphicsRectItem>
#include <QKeyEvent>
#include <QTimer>
//坦克类对象，构建坦克主体
class Tank : public QGraphicsRectItem {
public:
Tank() {
// 坦克身体
setRect(0, 0, 30, 50);
setBrush(Qt::blue);
// 炮塔
turret = new QGraphicsRectItem(10, -20, 10, 30);
turret->setParentItem(this);
// 设置炮塔颜色
turret->setBrush(Qt::red);
}
//重写键盘事件，判断上下左右、空格按钮
void keyPressEvent(QKeyEvent *event) override {
// Handle key presses to control the tank
switch (event->key()) {
case Qt::Key_Left:
moveBy(-10, 0);
break;
case Qt::Key_Right:
moveBy(10, 0);
break;
case Qt::Key_Up:
moveBy(0, -10);
break;
case Qt::Key_Down:
moveBy(0, 10);
break;
case Qt::Key_Space: //如果是空格键，发射炮弹
//绘制第一发炮弹
QGraphicsEllipseItem *bulletItem = new QGraphicsEllipseItem(0, 0, 5, 10);
bulletItem->setPos(mapToScene(12, -50));
bulletItem->setBrush(Qt::red);
scene()->addItem(bulletItem);
//记录第一发炮弹位置
QPointF pos = bulletItem->pos();
//每隔500ms,发射下一发炮弹，看着像连续的动画效果
QTimer::singleShot(500, [=]() {
//移除第一发炮弹
scene()->removeItem(bulletItem);
//绘制第二发炮弹
QGraphicsEllipseItem *bulletItem1 = new QGraphicsEllipseItem(0, 0, 5, 10);
bulletItem1->setPos(pos.x(), pos.y() - 30);
bulletItem1->setBrush(Qt::red);
scene()->addItem(bulletItem1);
QTimer::singleShot(500, [=]() {
//移除第二发炮弹
scene()->removeItem(bulletItem1);
//绘制第三发炮弹
QGraphicsEllipseItem *bulletItem2 = new QGraphicsEllipseItem(0, 0, 5, 10);
bulletItem2->setPos(pos.x(), pos.y() - 80);
bulletItem2->setBrush(Qt::red);
scene()->addItem(bulletItem2);
QTimer::singleShot(500, [=]() {
//移除第三发炮弹
scene()->removeItem(bulletItem2);
});
});
});
break;
// default:
// break;
}
}
private:
QGraphicsRectItem *turret; // 炮塔
};
//绘制主画布
class TankGame : public QGraphicsView {
public:
TankGame() {
scene = new QGraphicsScene(this); // 2D 图形 画布
setScene(scene);
//创建tank实例
tank = new Tank();
//加载tank实例到画布
scene->addItem(tank);
//抗锯齿渲染 减少图形边缘的锯齿状效果 使得图形看起来更加清晰和平滑
setRenderHint(QPainter::Antialiasing);
//平滑的像素变换渲染 用于对图片进行变换（如旋转、缩放等）时保持图片的平滑性
setRenderHint(QPainter::SmoothPixmapTransform);
//边界框发生变化时进行更新
setViewportUpdateMode(QGraphicsView::BoundingRectViewportUpdate);
//高质量抗锯齿渲染 与上边的代码类似 但是这个设置更加强调图形的质量而不是性能
setRenderHint(QPainter::HighQualityAntialiasing);
//设置了 画布 的大小为 800x600 像素
setFixedSize(800, 600);
}
//画布的键盘事件，调用tank类中的键盘事件
protected:
void keyPressEvent(QKeyEvent *event) override {
// Forward key events to the tank
tank->keyPressEvent(event);
}
private:
QGraphicsScene *scene; //画布实例
Tank *tank; //坦克实例
};
//主函数
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
//声明画布
TankGame tankGame;
//显示画布
tankGame.show();
return a.exec();
}
tank.pro文件中代码
QT -= core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
CONFIG += c++11
The following define makes your compiler emit warnings if you use
any Qt feature that has been marked deprecated (the exact warnings
depend on your compiler). Please consult the documentation of the
deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS
You can also make your code fail to compile if it uses deprecated APIs.
In order to do so, uncomment the following line.
You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000 # disables all the APIs deprecated before Qt 6.0.0
SOURCES += \
main.cpp
Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target