Linux+QT应用程序，设计一个简易密码键盘，并写出相关代码

好的，以下是一个简易密码键盘的代码实现：

passwordkeyboard.h

#ifndef PASSWORDKEYBOARD_H
#define PASSWORDKEYBOARD_H

#include <QWidget>
#include <QLineEdit>
#include <QPushButton>

class PasswordKeyboard : public QWidget
{
    Q_OBJECT

public:
    PasswordKeyboard(QWidget *parent = nullptr);

private:
    QLineEdit *m_passwordLineEdit;
    QPushButton *m_btn1;
    QPushButton *m_btn2;
    QPushButton *m_btn3;
    QPushButton *m_btn4;
    QPushButton *m_btn5;
    QPushButton *m_btn6;
    QPushButton *m_btn7;
    QPushButton *m_btn8;
    QPushButton *m_btn9;
    QPushButton *m_btn0;
    QPushButton *m_btnClear;
    QPushButton *m_btnConfirm;

private slots:
    void onBtn1Clicked();
    void onBtn2Clicked();
    void onBtn3Clicked();
    void onBtn4Clicked();
    void onBtn5Clicked();
    void onBtn6Clicked();
    void onBtn7Clicked();
    void onBtn8Clicked();
    void onBtn9Clicked();
    void onBtn0Clicked();
    void onBtnClearClicked();
    void onBtnConfirmClicked();
};

#endif // PASSWORDKEYBOARD_H

passwordkeyboard.cpp

#include "passwordkeyboard.h"
#include <QGridLayout>
#include <QMessageBox>

PasswordKeyboard::PasswordKeyboard(QWidget *parent)
    : QWidget(parent)
{
    // 创建界面元素
    m_passwordLineEdit = new QLineEdit;
    m_passwordLineEdit->setEchoMode(QLineEdit::Password);

    m_btn1 = new QPushButton("1");
    m_btn1->setObjectName("btn1");
    m_btn2 = new QPushButton("2");
    m_btn2->setObjectName("btn2");
    m_btn3 = new QPushButton("3");
    m_btn3->setObjectName("btn3");
    m_btn4 = new QPushButton("4");
    m_btn4->setObjectName("btn4");
    m_btn5 = new QPushButton("5");
    m_btn5->setObjectName("btn5");
    m_btn6 = new QPushButton("6");
    m_btn6->setObjectName("btn6");
    m_btn7 = new QPushButton("7");
    m_btn7->setObjectName("btn7");
    m_btn8 = new QPushButton("8");
    m_btn8->setObjectName("btn8");
    m_btn9 = new QPushButton("9");
    m_btn9->setObjectName("btn9");
    m_btn0 = new QPushButton("0");
    m_btn0->setObjectName("btn0");

    m_btnClear = new QPushButton("Clear");
    m_btnConfirm = new QPushButton("Confirm");

    // 创建布局
    QGridLayout *gridLayout = new QGridLayout;
    gridLayout->addWidget(m_btn1, 0, 0);
    gridLayout->addWidget(m_btn2, 0, 1);
    gridLayout->addWidget(m_btn3, 0, 2);
    gridLayout->addWidget(m_btn4, 1, 0);
    gridLayout->addWidget(m_btn5, 1, 1);
    gridLayout->addWidget(m_btn6, 1, 2);
    gridLayout->addWidget(m_btn7, 2, 0);
    gridLayout->addWidget(m_btn8, 2, 1);
    gridLayout->addWidget(m_btn9, 2, 2);
    gridLayout->addWidget(m_btnClear, 3, 0);
    gridLayout->addWidget(m_btn0, 3, 1);
    gridLayout->addWidget(m_btnConfirm, 3, 2);

    // 连接信号和槽
    connect(m_btn1, SIGNAL(clicked()), this, SLOT(onBtn1Clicked()));
    connect(m_btn2, SIGNAL(clicked()), this, SLOT(onBtn2Clicked()));
    connect(m_btn3, SIGNAL(clicked()), this, SLOT(onBtn3Clicked()));
    connect(m_btn4, SIGNAL(clicked()), this, SLOT(onBtn4Clicked()));
    connect(m_btn5, SIGNAL(clicked()), this, SLOT(onBtn5Clicked()));
    connect(m_btn6, SIGNAL(clicked()), this, SLOT(onBtn6Clicked()));
    connect(m_btn7, SIGNAL(clicked()), this, SLOT(onBtn7Clicked()));
    connect(m_btn8, SIGNAL(clicked()), this, SLOT(onBtn8Clicked()));
    connect(m_btn9, SIGNAL(clicked()), this, SLOT(onBtn9Clicked()));
    connect(m_btn0, SIGNAL(clicked()), this, SLOT(onBtn0Clicked()));
    connect(m_btnClear, SIGNAL(clicked()), this, SLOT(onBtnClearClicked()));
    connect(m_btnConfirm, SIGNAL(clicked()), this, SLOT(onBtnConfirmClicked()));

    // 设置布局
    setLayout(gridLayout);
}

void PasswordKeyboard::onBtn1Clicked()
{
    m_passwordLineEdit->insert("1");
}

void PasswordKeyboard::onBtn2Clicked()
{
    m_passwordLineEdit->insert("2");
}

void PasswordKeyboard::onBtn3Clicked()
{
    m_passwordLineEdit->insert("3");
}

void PasswordKeyboard::onBtn4Clicked()
{
    m_passwordLineEdit->insert("4");
}

void PasswordKeyboard::onBtn5Clicked()
{
    m_passwordLineEdit->insert("5");
}

void PasswordKeyboard::onBtn6Clicked()
{
    m_passwordLineEdit->insert("6");
}

void PasswordKeyboard::onBtn7Clicked()
{
    m_passwordLineEdit->insert("7");
}

void PasswordKeyboard::onBtn8Clicked()
{
    m_passwordLineEdit->insert("8");
}

void PasswordKeyboard::onBtn9Clicked()
{
    m_passwordLineEdit->insert("9");
}

void PasswordKeyboard::onBtn0Clicked()
{
    m_passwordLineEdit->insert("0");
}

void PasswordKeyboard::onBtnClearClicked()
{
    m_passwordLineEdit->clear();
}

void PasswordKeyboard::onBtnConfirmClicked()
{
    QString password = m_passwordLineEdit->text();
    if (password == "123456") {
        QMessageBox::information(this, "Success", "Password is correct!");
        m_passwordLineEdit->clear();
    } else {
        QMessageBox::warning(this, "Error", "Password is incorrect!");
        m_passwordLineEdit->clear();
    }
}

在主程序中，可以像下面这样使用PasswordKeyboard类：

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

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    PasswordKeyboard keyboard;
    keyboard.show();

    return a.exec();
}

这样，一个简易密码键盘就完成了。用户可以通过点击数字键来输入密码，点击Clear按钮可以清空密码，点击Confirm按钮可以验证密码是否正确。