Qt之鼠标随手画及画多边形
首先介绍下项目结构，其中
class Figure是
class FreeHand和
class Polygon的父类。
class ViewWidget是画图区，继承自
QWidget
下面介绍具体代码：
main.cpp
#include "Widgets/mainwindow.h"
#include
int main(int argc, char *argv[])
{
_CrtSetDbgFlag(_CrtSetDbgFlag(_CRTDBG_REPORT_FLAG) | _CRTDBG_LEAK_CHECK_DF);//内存检漏
QApplication a(argc, argv);
MainWindow main;
main.show();
return a.exec();
}
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include "Widgets/viewwidget.h"
#include
#include
#include
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
void Init();
void CreateButtons();
~MainWindow();
private:
QAction *hello_world_action_;
QToolBar *main_toolbar_;
QMenu *main_menu_;
ViewWidget* view_widget_; //声明ViewWidget指针
Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "Widgets/mainwindow.h"
#include "ui_mainwindow.h"
#include "Widgets/viewwidget.h"
#include
#include
#include
using namespace std;
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),ui(new Ui::MainWindow)
{
ui->setupUi(this);
Init();
}
void MainWindow::Init()
{
view_widget_ = new ViewWidget();
setCentralWidget(view_widget_);
CreateButtons();
}
void MainWindow::CreateButtons()
{
hello_world_action_ = new QAction(QIcon(":/Mainwindow/picture/Polygon"), tr("&Polygon"), this); //增加Polygon工具栏
connect(hello_world_action_, &QAction::triggered, view_widget_, &ViewWidget::set_figure_type_to_Polygon); //响应画多边形
main_menu_->addAction(hello_world_action_);
main_toolbar_->addSeparator();
main_toolbar_->addAction(hello_world_action_);
hello_world_action_ = new QAction(QIcon(":/Mainwindow/picture/FreeHand"), tr("&FreeHand"), this); //增加FreeHand工具栏
connect(hello_world_action_, &QAction::triggered, view_widget_, &ViewWidget::set_figure_type_to_FreeHand); //响应画自由曲线
main_menu_->addAction(hello_world_action_);
main_toolbar_->addSeparator();
main_toolbar_->addAction(hello_world_action_);
hello_world_action_ = new QAction(QIcon(":/Mainwindow/picture/Delete"), tr("&Delete"), this); //增加Delete工具栏
connect(hello_world_action_, &QAction::triggered, view_widget_, &ViewWidget::delete_last_action);
main_menu_->addAction(hello_world_action_);
main_toolbar_->addSeparator();
main_toolbar_->addAction(hello_world_action_);
hello_world_action_ = new QAction(tr("&About MiniDraw"), this);
connect(hello_world_action_, &QAction::triggered, view_widget_, &ViewWidget::set_figure_type_to_Rectangle);
}
MainWindow::~MainWindow()
{
delete ui;
}
viewwidget.h
#ifndef VIEWWIDGET_H
#define VIEWWIDGET_H
#include
#include
#include
#include
#include "Resource/figure.h"
#include "Resource/polygon.h"
#include "Resource/freehand.h"
using namespace std;
enum FigureType;
class ViewWidget : public QWidget
{
Q_OBJECT
public:
enum FigureType
{
kDefault = 0, kLine = 1, kRectangle = 2, kEllipse = 3, kPolygon = 4, kFreeHand = 5,
};
FigureType figure_type_;
vector<Figure*> figure_array_;
vector<Line*> line_array_;
explicit ViewWidget(QWidget *parent = 0);
void mousePressEvent(QMouseEvent *event);
void mouseMoveEvent(QMouseEvent *event);
void mouseReleaseEvent(QMouseEvent *event);
void paintEvent(QPaintEvent*);
void set_figure_type_to_Polygon();
void set_figure_type_to_FreeHand();
void delete_last_action();
~ViewWidget();
signals:
public slots:
private:
bool draw_status_; //绘制状态，true为绘制当前鼠标拖动的图元，false为不绘制
QPoint start_point_; //当前图元的起始点
QPoint end_point_; //当前图元的终点
QPoint current_point_;
vector<QPoint> points;
QPainterPath *path;
};
#endif // VIEWWIDGET_H
viewwidget.cpp
#include "Widgets/viewwidget.h"
#include
#include
#include
#include "Widgets/mainwindow.h"
#include
#include
ViewWidget::ViewWidget(QWidget *parent) : QWidget(parent)
{
draw_status_ = false; //初始状态为不绘制
this->path = NULL;
}
void ViewWidget::mousePressEvent(QMouseEvent* event) //鼠标击发响应函数主体
{
if(Qt::LeftButton == event->button()) //判断鼠标是否左击
{
draw_status_ = true; //设置绘制状态为——绘制
start_point_ = end_point_ = event->pos(); //将图元初始点设置为当前鼠标击发点
if(figure_type_ == kPolygon)
{
points.push_back(start_point_);
}
if(figure_type_ == kFreeHand)
{
path = new QPainterPath;
path->moveTo(event->pos());
}
}
}
void ViewWidget::mouseMoveEvent(QMouseEvent *event) //鼠标移动响应函数主体
{
if(draw_status_) //判断当前绘制状态
{
end_point_ = event->pos(); //若为真，则设置图元终止点为当前鼠标位置
}
if(figure_type_ == kFreeHand)
{
path->lineTo(event->pos());
}
}
void ViewWidget::mouseReleaseEvent(QMouseEvent *event) //鼠标释放响应函数主体
{
Figure* current_figure_ = NULL;
switch(figure_type_)
{
case kDefault:
break;
case kPolygon:
points.push_back(end_point_);
if(Qt::RightButton == event->button())
{
current_figure_ = new Polygon(points);
figure_array_.push_back(current_figure_);
points.clear();
}
break;
case kFreeHand:
current_figure_ = new FreeHand(*path);
figure_array_.push_back(current_figure_);
draw_status_ = false;
delete path;
path = NULL;
break;
default:
break;
}
current_figure_ = NULL;
}
void ViewWidget::paintEvent(QPaintEvent *)
{
QPainter painter(this); //定义painter
for(size_t i = 0; i < figure_array_.size(); i++)
{
if(figure_array_[i] != NULL)
figure_array_[i]->Draw(painter);
}
if(draw_status_)
{
switch(figure_type_)
{
case kDefault:
break;
case kFreeHand:
std::cout<<"4"<<std::endl;
if(path != NULL)
painter.drawPath(*path);
break;
case kPolygon:
if(points.size()==0)
{
break;
}
QPoint pre = points[0];
for(int i=1;i < points.size();i++)
{
painter.drawLine(pre,points[i]);
pre = points[i];
}
break;
}
}
update();
}
void ViewWidget::set_figure_type_to_Polygon()
{
figure_type_ = kPolygon;
}
void ViewWidget::set_figure_type_to_FreeHand()
{
figure_type_ = kFreeHand;
}
void ViewWidget::delete_last_action()
{
if(!figure_array_.empty())
{
delete figure_array_.back();
figure_array_.pop_back();
}
}
ViewWidget::~ViewWidget()
{
for(size_t i = 0; i < figure_array_.size(); i++)
{
if(figure_array_[i])
{
delete figure_array_[i];
}
}
figure_array_.clear();
}
figure.h
#ifndef FIGURE_H
#define FIGURE_H
#include
class Figure
{
public:
Figure();
virtual void Draw(QPainter &);
virtual ~Figure();
};
#endif // FIGURE_H
figure.cpp
#include "Resource/figure.h"
#include
Figure::Figure()
{
}
Figure::~Figure()
{
}
void Figure::Draw(QPainter &)
{
}
freehand.h
#ifndef FREEHAND_H
#define FREEHAND_H
#include"Resource/figure.h"
#include
#include
class FreeHand : public Figure
{
public:
FreeHand();
FreeHand( QPainterPath paths);
void Draw(QPainter &paint);
// void addPoint(QPoint point);
~FreeHand();
private:
QPainterPath path;
// QVectorpoints;
};
#endif // FREEHAND_H
freehand.cpp
#include "Resource/freehand.h"
#include
#include
#include
FreeHand::FreeHand(QPainterPath paths)
{
path = paths;
}
void FreeHand::Draw(QPainter& paint)
{
paint.drawPath(path);
}
FreeHand::~FreeHand()
{
}
polygon.h
#ifndef POLYGON_H
#define POLYGON_H
#include "Resource/figure.h"
#include
using namespace std;
class Polygon : public Figure
{
public:
Polygon();
Polygon(const vector<QPoint> points);
void Draw(QPainter& paint);
~Polygon();
private:
vector<QPoint> point;
};
#endif // POLYGON_H
polygon.cpp
#include "Resource/polygon.h"
#include
#include
using namespace std;
Polygon::Polygon()
{
}
Polygon::Polygon(const vector<QPoint> points)
{
point = points;
}
void Polygon::Draw(QPainter &paint)
{
paint.drawPolygon(&point.at(0),point.size());
}
Polygon::~Polygon()
{
}
好了，以上是这个程序的代码，我是第一次写博客，也不知道怎么说，就直接贴代码了。