qt设计一个计算机的代码

好的，下面是一个简单的Qt计算器的代码，包括界面和基本的计算逻辑。这里的代码只实现了加减乘除四种基本运算，你可以根据需要进行修改和扩展。

mainwindow.h：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QLineEdit>
#include <QPushButton>

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void digitClicked();
    void operatorClicked();
    void clearClicked();
    void equalsClicked();

private:
    QLineEdit *display;
    QPushButton *digitButtons[10];
    QPushButton *addButton;
    QPushButton *subtractButton;
    QPushButton *multiplyButton;
    QPushButton *divideButton;
    QPushButton *clearButton;
    QPushButton *equalsButton;

    QString pendingOperator;
    double operand1;
    double operand2;
};

#endif // MAINWINDOW_H

mainwindow.cpp：

#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    // Create display widget
    display = new QLineEdit(this);
    display->setReadOnly(true);
    display->setAlignment(Qt::AlignRight);
    display->setMaxLength(15);
    display->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);

    // Create digit buttons
    for (int i = 0; i < 10; ++i) {
        digitButtons[i] = new QPushButton(QString::number(i), this);
        digitButtons[i]->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    }

    // Create operator buttons
    addButton = new QPushButton("+", this);
    subtractButton = new QPushButton("-", this);
    multiplyButton = new QPushButton("*", this);
    divideButton = new QPushButton("/", this);
    clearButton = new QPushButton("C", this);
    equalsButton = new QPushButton("=", this);

    // Create layout
    QGridLayout *layout = new QGridLayout;
    layout->addWidget(display, 0, 0, 1, 4);
    layout->addWidget(digitButtons[7], 1, 0);
    layout->addWidget(digitButtons[8], 1, 1);
    layout->addWidget(digitButtons[9], 1, 2);
    layout->addWidget(addButton, 1, 3);
    layout->addWidget(digitButtons[4], 2, 0);
    layout->addWidget(digitButtons[5], 2, 1);
    layout->addWidget(digitButtons[6], 2, 2);
    layout->addWidget(subtractButton, 2, 3);
    layout->addWidget(digitButtons[1], 3, 0);
    layout->addWidget(digitButtons[2], 3, 1);
    layout->addWidget(digitButtons[3], 3, 2);
    layout->addWidget(multiplyButton, 3, 3);
    layout->addWidget(digitButtons[0], 4, 0, 1, 2);
    layout->addWidget(divideButton, 4, 3);
    layout->addWidget(clearButton, 5, 0);
    layout->addWidget(equalsButton, 5, 1, 1, 2);

    QWidget *centralWidget = new QWidget(this);
    centralWidget->setLayout(layout);
    setCentralWidget(centralWidget);

    // Connect signals and slots
    for (int i = 0; i < 10; ++i) {
        connect(digitButtons[i], &QPushButton::clicked, this, &MainWindow::digitClicked);
    }
    connect(addButton, &QPushButton::clicked, this, &MainWindow::operatorClicked);
    connect(subtractButton, &QPushButton::clicked, this, &MainWindow::operatorClicked);
    connect(multiplyButton, &QPushButton::clicked, this, &MainWindow::operatorClicked);
    connect(divideButton, &QPushButton::clicked, this, &MainWindow::operatorClicked);
    connect(clearButton, &QPushButton::clicked, this, &MainWindow::clearClicked);
    connect(equalsButton, &QPushButton::clicked, this, &MainWindow::equalsClicked);

    // Initialize variables
    pendingOperator = "";
    operand1 = 0.0;
    operand2 = 0.0;
}

MainWindow::~MainWindow()
{
}

void MainWindow::digitClicked()
{
    QPushButton *button = qobject_cast<QPushButton *>(sender());
    if (button) {
        QString digit = button->text();
        QString text = display->text();
        if (text == "0") {
            text = digit;
        } else {
            text += digit;
        }
        display->setText(text);
    }
}

void MainWindow::operatorClicked()
{
    QPushButton *button = qobject_cast<QPushButton *>(sender());
    if (button) {
        QString op = button->text();
        if (pendingOperator == "") {
            operand1 = display->text().toDouble();
            pendingOperator = op;
            display->setText("");
        } else {
            operand2 = display->text().toDouble();
            if (pendingOperator == "+") {
                operand1 += operand2;
            } else if (pendingOperator == "-") {
                operand1 -= operand2;
            } else if (pendingOperator == "*") {
                operand1 *= operand2;
            } else if (pendingOperator == "/") {
                if (operand2 == 0.0) {
                    display->setText("Error");
                    return;
                } else {
                    operand1 /= operand2;
                }
            }
            pendingOperator = op;
            display->setText(QString::number(operand1));
        }
    }
}

void MainWindow::clearClicked()
{
    pendingOperator = "";
    operand1 = 0.0;
    operand2 = 0.0;
    display->setText("0");
}

void MainWindow::equalsClicked()
{
    if (pendingOperator != "") {
        operand2 = display->text().toDouble();
        if (pendingOperator == "+") {
            operand1 += operand2;
        } else if (pendingOperator == "-") {
            operand1 -= operand2;
        } else if (pendingOperator == "*") {
            operand1 *= operand2;
        } else if (pendingOperator == "/") {
            if (operand2 == 0.0) {
                display->setText("Error");
                return;
            } else {
                operand1 /= operand2;
            }
        }
        pendingOperator = "";
        display->setText(QString::number(operand1));
    }
}

在这个例子中，我们将QPushButton控件的clicked信号连接到对应的槽函数中，这样当用户点击按钮时，对应的槽函数就会被调用。digitClicked()槽函数用于处理数字按钮的点击事件，operatorClicked()槽函数用于处理运算符按钮的点击事件，clearClicked()槽函数用于处理“C”按钮的点击事件，equalsClicked()槽函数用于处理“=”按钮的点击事件。

在每个槽函数中，我们使用QLineEdit控件的setText()函数来更新计算结果。对于运算符按钮，我们将操作数1和操作数2存储在类成员变量中，并在用户点击“=”按钮时进行计算。注意，在计算除法时，我们需要检查除数是否为0，如果是，就显示“Error”。

这只是一个简单的例子，你可以根据需要进行修改和扩展。