32.QT绘图

widget.h

 1 #ifndef WIDGET_H
 2 #define WIDGET_H
 3 
 4 #include <QWidget>
 5 #include <QPainter>
 6 #include <QPen>
 7 #include <QEvent>
 8 
 9 namespace Ui {
10 class Widget;
11 }
12 
13 class Widget : public QWidget
14 {
15     Q_OBJECT
16 
17 public:
18     explicit Widget(QWidget *parent = 0);
19     ~Widget();
20     void paintEvent(QPaintEvent *e);
21     QPainter *painter;
22 
23 private:
24     Ui::Widget *ui;
25 };
26 
27 #endif // WIDGET_H

widget.cpp

 1 #include "widget.h"
 2 #include "ui_widget.h"
 3 
 4 Widget::Widget(QWidget *parent) :
 5     QWidget(parent),
 6     ui(new Ui::Widget)
 7 {
 8     ui->setupUi(this);
 9     setGeometry(120,120,600,600);
10 }
11 
12 Widget::~Widget()
13 {
14     delete ui;
15 }
16 
17 void Widget::paintEvent(QPaintEvent *e)
18 {
19     painter = new QPainter;
20     painter->begin(this);
21     painter->setPen(QPen(Qt::blue,10,Qt::DashDotLine));
22 
23     //画刷
24     painter->setBrush(QBrush(Qt::red,Qt::SolidPattern));
25     //画矩形
26     //painter->drawRect(20,20,180,180);
27     //画椭圆
28     //painter->drawEllipse(20,20,190,160);
29     //画点
30     //painter->drawPoint(100,100);
31     //画曲线
32    // painter->drawArc(20,20,210,160,500,1000);
33 
34 
35     /*
36         case Line:                                             //直线
37             p.drawLine(rect.topLeft(),rect.bottomRight());     break;
38         case Rectangle:                                        //长方形
39             p.drawRect(rect);    break;
40         case RoundRect:                                        //圆角方形
41             p.drawRoundRect(rect);     break;
42         case Ellipse:                                          //椭圆形
43             p.drawEllipse(rect);     break;
44         case Polygon:                                          //多边形
45             p.drawPolygon(points,4);     break;
46         case Polyline:                                      //多边线
47             p.drawPolyline(points,4);     break;
48         case Points:                                          //点
49             p.drawPoints(points,4);     break;
50         case Arc:                                              //弧
51             p.drawArc(rect,startAngle,spanAngle);     break;
52         case Path:                                             //路径
53             p.drawPath(path);     break;
54         case Text:                                            //文字
55             p.drawText(rect,Qt::AlignCenter,tr("Hello Qt!"));    break;
56         case Pixmap:                                          //图片
57             p.drawPixmap(150,150,QPixmap("butterfly.png"));     break;
58         default:     break;
59 
60 
61 
62 
63        painter->drawLine(QPoint(30,30),QPoint(60,180));
64        painter->drawText(this->rect(),Qt::AlignCenter,tr("Hello Qthello haihua!"));
65        painter->drawPixmap(150,150,QPixmap("1.png"));
66     */
67 
68     //画线
69     //painter->drawLine(QPoint(30,30),QPoint(60,180));
70     //painter->drawText(this->rect(),Qt::AlignCenter,tr("Hello"));
71     //画图
72     painter->drawPixmap(0,0,QPixmap("1.png"));
73     painter->end();
74 }