幸运电子转盘
- 基础绘图
- 通过paintEvent来绘图
- 鼠标事件：鼠标左键单击开始旋转
- Timer：定时器
- 信号与槽
1 #ifndef WIDGET_H
2 #define WIDGET_H
3
4 #include <QWidget>
5 #include <QEvent>
6 #include <QDebug>
7 #include <QTimer>
8 #include <QTime>
9 #include <QMouseEvent>
10 #include <QPainter>
11
12 QT_BEGIN_NAMESPACE
13 namespace Ui { class Widget; }
14 QT_END_NAMESPACE
15
16 class Widget : public QWidget
17 {
18 Q_OBJECT
19
20 public:
21 Widget(QWidget *parent = nullptr);
22 ~Widget();
23
24 protected:
25 // 绘图事件 ：显示隐藏 resize update
26 virtual void paintEvent(QPaintEvent *event);
27 virtual void mousePressEvent(QMouseEvent *event);
28
29
30 public slots:
31 void rtTimerOutSlot();
32 void luckStartSlot();
33 signals:
34 void luckStartSignal();
35 private:
36 Ui::Widget *ui;
37
38 private:
39 // 堆区对象 画家
40 QPainter rotationPainter;
41 QPainter pointPainter;
42
43 // 定时器
44 QTimer rtTimer;
45
46 // 角度
47 qreal rtAngle;
48 int randNumber;
49
50 };
51 #endif // WIDGET_H
1 #include "widget.h"
2 #include "ui_widget.h"
3
4 Widget::Widget(QWidget *parent)
5 : QWidget(parent)
6 , ui(new Ui::Widget)
7 ,rtAngle(0.0)
8 {
9 ui->setupUi(this);
10
11 connect(this,SIGNAL(luckStartSignal()),this,
12 SLOT(luckStartSlot()));
13
14 connect(&rtTimer,SIGNAL(timeout()),this,SLOT(rtTimerOutSlot()));
15 }
16
17 Widget::~Widget()
18 {
19 delete ui;
20 }
21
22 void Widget::paintEvent(QPaintEvent *event)
23 {
24 // 先准备一个画笔
25 rotationPainter.begin(this);
26 // 移动坐标
27 rotationPainter.translate(200,200);
28 // 旋转
29 rotationPainter.rotate(rtAngle);
30 // 设置反锯齿
31 rotationPainter.setRenderHints(QPainter::SmoothPixmapTransform);
32 // 0,0 为POS
33 rotationPainter.drawPixmap(-200,-200,400,400,QPixmap(":/img/1.jpg")); // pos
34 rotationPainter.end();
35
36 // 绘制指针
37 pointPainter.begin(this);
38 pointPainter.translate(200,200);// 原点移动
39 static const QPoint point[4] = {QPoint(0,18),QPoint(20,0),
40 QPoint(0,-100),QPoint(-20,0)};
41 // 设置画笔
42 pointPainter.setBrush(QColor(Qt::darkBlue));
43 // 添加反锯齿（走样） 设置抗锯齿需要再绘图之前添加
44 pointPainter.setRenderHints(QPainter::Antialiasing);
45 // 描点画出多边形
46 pointPainter.drawPolygon(point, 4);
47
48 // 多边形
49 QRect recatanle(-7,-7,14,18);
50 pointPainter.setBrush(QColor(Qt::yellow));
51 pointPainter.drawEllipse(recatanle);
52 pointPainter.end();
53 }
54
55 void Widget::rtTimerOutSlot()
56 {
57 rtAngle++; //旋转因子
58
59 if((rtAngle - randNumber) == 90)
60 {
61 rtTimer.setInterval(10);
62 }
63 else if((rtAngle - randNumber) == 180)
64
65 {
66 rtTimer.setInterval(15);
67 }
68 else if((rtAngle - randNumber) == 270)
69 {
70 rtTimer.setInterval(20);
71 }
72 else if((rtAngle - randNumber) == 360)
73 {
74 rtAngle--; //停下来
75 }
76 update(); // 更新视图
77 }
78
79 void Widget::luckStartSlot()
80 {
81 rtAngle = 1;
82 srand(QTime(0,0,0).secsTo(QTime::currentTime()));
83 randNumber = rand()%360 +180;// 180 -> 360之间
84 rtTimer.start(5);
85 }
86
87 void Widget::mousePressEvent(QMouseEvent *event)
88 {
89 if(event->button() == Qt::LeftButton)
90 {
91 if(event->pos().x() >180 && event->pos().x()<220
92 && event->pos().y()<216 && event->pos().y()>130)
93 {
94 emit luckStartSignal();
95 }
96 }
97
98 }
