QT 制作简易几何计算器

 

一、新建项目并添加类文件

二、ui界面设计

三、连接Combo Box对象与Stacked Widget对象

四、结果及源代码

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一、新建项目并添加类文件

1.新建一个名为“calculate_area”的继承自mainWindow类的项目。

   此时工程目录下有5个文件：mainwindow.h、mainwindow.cpp、mainwindow.ui、main.cpp、calculate_area.pro。

2.添加3个Qt设计类界面(Dialog without Buttons模板)，类名分别为：area（计算面积）、length（计算周长）、volume（计算体积）。

   此时工程目录下增加了6个文件：area.h、area.cpp、length.h、length.cpp、volume.h、volum.cpp

项目树形图如下所示：

                                  

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二、ui界面设计

1.双击mainwin.ui，拖入三个push Button控件。如下图所示：

2.双击area.ui，拖入push Button、Label、lineedit、Stacked Widget、Combo Box控件

   2.1 双击Combo Box，在编辑组合框内添加4个选项：长方形、正方形、圆形、三角形

  2.2 Stacked Widget里添加4页（下图是第一页，第2~4页分别是正方形、圆形、三角形相关控件），设置成如下形式（并分别修改lineedit、push Button对象名，便于辨认）。

        

3 同理length.ui以及volum.ui界面设计如下：

 

         

         

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三、连接Combo Box对象与Stacked Widget对象

以area类为例（class length 及class volume类似）。

在mainwindow.h下添加头文件：“area.h”、“length.h”、“volume.h”

1.双击mainwindow.ui。选中“面积计算”button，右键点击“转到槽”选择”clicked()”。在槽函数里添加 如下代码：

void MainWindow::on_area_btn_clicked()
{
    area area_model;
    area_model.setWindowTitle("面积");
    area_model.exec();
}

2.双击area.ui。选中combo Box对象，右键点击“转到槽”选择“currentIndexChanged(QString)”。在槽函数里添加如下代码：

void area::on_comboBox_currentTextChanged(const QString &arg1)
{
    //若comboBox当前显示的是“长方形选项”，则设置当前stackedWidget页码索引为0（第0页为首页）
    if(ui->comboBox->currentText()=="长方形")
    {
        ui->stackedWidget->setCurrentIndex(0);
    }
    if(ui->comboBox->currentText()=="正方形")
    {
        ui->stackedWidget->setCurrentIndex(1);
    }
    if(ui->comboBox->currentText()=="圆形")
    {
        ui->stackedWidget->setCurrentIndex(2);
    }
    if(ui->comboBox->currentText()=="三角形")
    {
        ui->stackedWidget->setCurrentIndex(3);
    }
}

3.双击area.ui。选中“计算”按钮，右键点击“转到槽”选择“clicked()”。在槽函数里添加如下代码：

void area::on_cal_clicked()
{
    //获取当前页码索引，获取当前用户输入数据，分别计算各图形的面积
    if(ui->stackedWidget->currentIndex()==0)
    {
        double heigh = ui->Rec_line_heigh->text().toDouble();
        double width = ui->Rec_line_width->text().toDouble();
        ui->Rec_line_area->setText(QString::number(heigh * width));
    }

    if(ui->stackedWidget->currentIndex()==1)
    {
        double edge = ui->Squ_line_width->text().toDouble();
        ui->Squ_line_area ->setText(QString::number(edge * edge));
    }

    if(ui->stackedWidget->currentIndex()==2)
    {
        double radius = ui->Cir_line_radius ->text().toDouble();
        ui->Cir_line_area->setText(QString::number(3.1415*radius*radius));
    }

    if(ui->stackedWidget->currentIndex()==3)
    {
        double heigh = ui->Tri_line_heigh ->text().toDouble();
        double width = ui->Tri_line_eage ->text().toDouble();
        ui->Tri_line_area->setText(QString::number(0.5*heigh*width));
    }

}

---

四、结果及源代码

生成exe可执行文件

主界面：

点击任意一个选项进行相关计算（如面积计算）：

选择计算长方形面积：输入长宽数据：

点击计算按钮，得出结果：

---

以下是源代码：

/********************mainwindow.h****************************/

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QDialog>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

private slots:
    void on_area_btn_clicked();

    void on_length_btn_clicked();

    void on_pushButton_3_clicked();

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

/********************mainwindow.cpp****************************/

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QComboBox>
#include "area.h"
#include "length.h"
#include "volume.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_area_btn_clicked()
{
    area area_model;
    area_model.setWindowTitle("面积");
    area_model.exec();
}

void MainWindow::on_length_btn_clicked()
{
    length length_model;
    length_model.setWindowTitle("周长");
    length_model.exec();
}

void MainWindow::on_pushButton_3_clicked()
{
    volume volume_model;
    volume_model.setWindowTitle("体积");
    volume_model.exec();
}

/**********************area.h*********************************/

#ifndef AREA_H
#define AREA_H

#include <QDialog>

namespace Ui {
class area;
}

class area : public QDialog
{
    Q_OBJECT

public:
    explicit area(QWidget *parent = 0);
    ~area();


private slots:
    void on_comboBox_currentTextChanged(const QString &arg1);

    void on_cal_clicked();

private:
    Ui::area *ui;
};

#endif // AREA_H

/**********************area.cpp*********************************/


#include "area.h"
#include "ui_area.h"
#include <QDebug>

area::area(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::area)
{
    ui->setupUi(this);
}

area::~area()
{
    delete ui;
}


void area::on_comboBox_currentTextChanged(const QString &arg1)
{
    if(ui->comboBox->currentText()=="长方形")
    {
        ui->stackedWidget->setCurrentIndex(0);
    }
    if(ui->comboBox->currentText()=="正方形")
    {
        ui->stackedWidget->setCurrentIndex(1);
    }
    if(ui->comboBox->currentText()=="圆形")
    {
        ui->stackedWidget->setCurrentIndex(2);
    }
    if(ui->comboBox->currentText()=="三角形")
    {
        ui->stackedWidget->setCurrentIndex(3);
    }
}

void area::on_cal_clicked()
{
    if(ui->stackedWidget->currentIndex()==0)
    {
        double heigh = ui->Rec_line_heigh->text().toDouble();
        double width = ui->Rec_line_width->text().toDouble();
        ui->Rec_line_area->setText(QString::number(heigh * width));
    }

    if(ui->stackedWidget->currentIndex()==1)
    {
        double edge = ui->Squ_line_width->text().toDouble();
        ui->Squ_line_area ->setText(QString::number(edge * edge));
    }

    if(ui->stackedWidget->currentIndex()==2)
    {
        double radius = ui->Cir_line_radius ->text().toDouble();
        ui->Cir_line_area->setText(QString::number(3.1415*radius*radius));
    }

    if(ui->stackedWidget->currentIndex()==3)
    {
        double heigh = ui->Tri_line_heigh ->text().toDouble();
        double width = ui->Tri_line_eage ->text().toDouble();
        ui->Tri_line_area->setText(QString::number(0.5*heigh*width));
    }

}

/**********************length.h********************************/

#ifndef LENGTH_H
#define LENGTH_H

#include <QDialog>

namespace Ui {
class length;
}

class length : public QDialog
{
    Q_OBJECT

public:
    explicit length(QWidget *parent = 0);
    ~length();

private slots:

    void on_comboBox_currentIndexChanged(const QString &arg1);

    void on_cal_clicked();

private:
    Ui::length *ui;
};

#endif // LENGTH_H

/*********************length.cpp*******************************/

#include "length.h"
#include "ui_length.h"

length::length(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::length)
{
    ui->setupUi(this);
}

length::~length()
{
    delete ui;
}

void length::on_comboBox_currentIndexChanged(const QString &arg1)
{

    if(ui->comboBox->currentText()=="长方形")
    {
        ui->stackedWidget->setCurrentIndex(0);
    }
    if(ui->comboBox->currentText()=="正方形")
    {
        ui->stackedWidget->setCurrentIndex(1);
    }
    if(ui->comboBox->currentText()=="圆形")
    {
        ui->stackedWidget->setCurrentIndex(2);
    }
    if(ui->comboBox->currentText()=="三角形")
    {
        ui->stackedWidget->setCurrentIndex(3);
    }
}

void length::on_cal_clicked()
{
    if(ui->stackedWidget->currentIndex()==0)
    {
        double heigh = ui->Rec_line_heigh->text().toDouble();
        double width = ui->Rec_line_width->text().toDouble();
        ui->Rec_line_length ->setText(QString::number(2*(heigh + width)));
    }

    if(ui->stackedWidget->currentIndex()==1)
    {
        double edge = ui->Squ_line_width->text().toDouble();
        ui->Squ_line_length ->setText(QString::number(4*edge));
    }

    if(ui->stackedWidget->currentIndex()==2)
    {
        double radius = ui->Cir_line_radius ->text().toDouble();
        ui->Cir_line_length->setText(QString::number(2*3.1415*radius));
    }

    if(ui->stackedWidget->currentIndex()==3)
    {
        double edge1 = ui->Tri_line_eage1 ->text().toDouble();
        double edge2 = ui->Tri_line_eage2 ->text().toDouble();
        double edge3 = ui->Tri_line_eage3 ->text().toDouble();
        ui->Tri_line_length->setText(QString::number(edge1+edge2+edge3));
    }

}

/**********************volume.h*******************************/

#ifndef VOLUME_H
#define VOLUME_H

#include <QDialog>

namespace Ui {
class volume;
}

class volume : public QDialog
{
    Q_OBJECT

public:
    explicit volume(QWidget *parent = 0);
    ~volume();

private slots:
    void on_comboBox_currentIndexChanged(const QString &arg1);

    void on_cal_clicked();

private:
    Ui::volume *ui;
};

#endif // VOLUME_H

/**********************volume.cpp******************************/

#include "volume.h"
#include "ui_volume.h"

volume::volume(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::volume)
{
    ui->setupUi(this);
}

volume::~volume()
{
    delete ui;
}

void volume::on_comboBox_currentIndexChanged(const QString &arg1)
{

    if(ui->comboBox->currentText()=="长方体")
    {
        ui->stackedWidget->setCurrentIndex(0);
    }
    if(ui->comboBox->currentText()=="正方体")
    {
        ui->stackedWidget->setCurrentIndex(1);
    }
    if(ui->comboBox->currentText()=="圆柱体")
    {
        ui->stackedWidget->setCurrentIndex(2);
    }
    if(ui->comboBox->currentText()=="圆锥体")
    {
        ui->stackedWidget->setCurrentIndex(3);
    }
    if(ui->comboBox->currentText()=="球体")
    {
        ui->stackedWidget->setCurrentIndex(4);
    }
}

void volume::on_cal_clicked()
{
    if(ui->stackedWidget->currentIndex()==0)
    {
        double heigh = ui->Rec_line_heigh->text().toDouble();
        double width = ui->Rec_line_width->text().toDouble();
        double longs = ui->Rec_line_long->text().toDouble();
        ui->Rec_line_volume->setText(QString::number(heigh * width *longs));
    }

    if(ui->stackedWidget->currentIndex()==1)
    {
        double edge = ui->Squ_line_width->text().toDouble();
        ui->Squ_line_volume ->setText(QString::number(edge * edge * edge));
    }

    if(ui->stackedWidget->currentIndex()==2)
    {
        double radius = ui->Cir_line_radius ->text().toDouble();
        double heigh = ui->Cir_line_heigh->text().toDouble();
        ui->Cir_line_volume->setText(QString::number(3.1415*radius * radius * heigh));
    }

    if(ui->stackedWidget->currentIndex()==3)
    {
        double heigh = ui->Cir_tri_line_heigh ->text().toDouble();
        double radius = ui->Cir_tri_line_radius ->text().toDouble();
        ui->Cir_tri_line_volume->setText(QString::number(1.0/3.0*(3.1415 * radius * radius) * heigh));
    }
    if(ui->stackedWidget->currentIndex()==4)
    {
        double radius = ui->ball_line_eage ->text().toDouble();
        ui->ball_line_volume->setText(QString::number(4.0/3.0 * 3.1415 * radius * radius * radius));
    }
}

/*************************main.cpp****************************/

#include "mainwindow.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.setWindowTitle("几何计算");
    w.show();

    return a.exec();
}