写出qt完整代码1. 实现一个简单计算器：可以实现整数的加减运算，要求控件的布局采用布局管理器来管理。（在实现运算的时候要注意QString类型与int类型数值之间的转换） 2. 创建一用户注册登录对话框模拟用户注册登录过程。要求验证用户名密码是否正确，验证失败信息用消息对话框提示。验证成功则重新打开一个新的对话框，该对话框上显示当前用户的姓名、学号、班级、地址等信息。 3. 实现一个简单的文本编辑器。要求： （1） 该窗口有标题栏、菜单栏和工具栏，请使用setwindowtittle（）方法设置标题。 （2） 菜单栏有file和edit两个下拉菜单。File菜单下有新建、打开、退出三个action；Edit菜单下有复制、粘贴、剪切三个action。 （3） 创建一个edit工具栏，该工具栏包含保存、剪切、粘贴三个action。

好的，下面是Qt完整代码，包含三个部分，分别实现了三个功能：

1. 实现一个简单计算器

#include <QApplication>
#include <QHBoxLayout>
#include <QVBoxLayout>
#include <QLabel>
#include <QLineEdit>
#include <QPushButton>

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

    // 创建窗口和控件
    QWidget *w = new QWidget;
    QLabel *label1 = new QLabel("Number 1:");
    QLabel *label2 = new QLabel("Number 2:");
    QLineEdit *lineEdit1 = new QLineEdit;
    QLineEdit *lineEdit2 = new QLineEdit;
    QLabel *resultLabel = new QLabel("Result:");
    QPushButton *addButton = new QPushButton("Add");
    QPushButton *subButton = new QPushButton("Subtract");

    // 创建布局管理器
    QVBoxLayout *vLayout = new QVBoxLayout;
    QHBoxLayout *hLayout1 = new QHBoxLayout;
    QHBoxLayout *hLayout2 = new QHBoxLayout;

    // 添加控件到布局管理器中
    hLayout1->addWidget(label1);
    hLayout1->addWidget(lineEdit1);
    hLayout2->addWidget(label2);
    hLayout2->addWidget(lineEdit2);
    vLayout->addLayout(hLayout1);
    vLayout->addLayout(hLayout2);
    vLayout->addWidget(resultLabel);
    vLayout->addWidget(addButton);
    vLayout->addWidget(subButton);
    w->setLayout(vLayout);

    // 设置窗口标题
    w->setWindowTitle("Calculator");

    // 连接按钮的Click事件
    QObject::connect(addButton, &QPushButton::clicked, [=](){
        int num1 = lineEdit1->text().toInt();
        int num2 = lineEdit2->text().toInt();
        int result = num1 + num2;
        resultLabel->setText("Result: " + QString::number(result));
    });
    QObject::connect(subButton, &QPushButton::clicked, [=](){
        int num1 = lineEdit1->text().toInt();
        int num2 = lineEdit2->text().toInt();
        int result = num1 - num2;
        resultLabel->setText("Result: " + QString::number(result));
    });

    // 显示窗口
    w->show();

    return a.exec();
}

2. 创建一用户注册登录对话框模拟用户注册登录过程

#include <QApplication>
#include <QDialog>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QLabel>
#include <QLineEdit>
#include <QPushButton>
#include <QMessageBox>

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

    // 创建主窗口和控件
    QDialog *mainWin = new QDialog;
    QLabel *userLabel = new QLabel("Username:");
    QLabel *passLabel = new QLabel("Password:");
    QLineEdit *userLineEdit = new QLineEdit;
    QLineEdit *passLineEdit = new QLineEdit;
    QPushButton *loginButton = new QPushButton("Login");
    QPushButton *regButton = new QPushButton("Register");

    // 创建布局管理器
    QVBoxLayout *vLayout = new QVBoxLayout;
    QHBoxLayout *hLayout1 = new QHBoxLayout;
    QHBoxLayout *hLayout2 = new QHBoxLayout;

    // 添加控件到布局管理器中
    hLayout1->addWidget(userLabel);
    hLayout1->addWidget(userLineEdit);
    hLayout2->addWidget(passLabel);
    hLayout2->addWidget(passLineEdit);
    vLayout->addLayout(hLayout1);
    vLayout->addLayout(hLayout2);
    vLayout->addWidget(loginButton);
    vLayout->addWidget(regButton);
    mainWin->setLayout(vLayout);

    // 设置窗口标题
    mainWin->setWindowTitle("Login/Register");

    // 连接按钮的Click事件
    QObject::connect(loginButton, &QPushButton::clicked, [=](){
        QString username = userLineEdit->text();
        QString password = passLineEdit->text();
        if(username == "admin" && password == "password"){
            QDialog *userInfoWin = new QDialog;
            QVBoxLayout *vLayout = new QVBoxLayout;
            QLabel *nameLabel = new QLabel("Name: John");
            QLabel *idLabel = new QLabel("ID: 123456");
            QLabel *classLabel = new QLabel("Class: A1");
            QLabel *addressLabel = new QLabel("Address: No.1 Road");
            vLayout->addWidget(nameLabel);
            vLayout->addWidget(idLabel);
            vLayout->addWidget(classLabel);
            vLayout->addWidget(addressLabel);
            userInfoWin->setLayout(vLayout);
            userInfoWin->setWindowTitle("User Information");
            userInfoWin->exec();
        }else{
            QMessageBox::warning(mainWin, "Login Failed", "Invalid username or password!");
        }
    });
    QObject::connect(regButton, &QPushButton::clicked, [=](){
        QMessageBox::information(mainWin, "Register", "Registration is not supported in this demo!");
    });

    // 显示窗口
    mainWin->show();

    return a.exec();
}

3. 实现一个简单的文本编辑器

#include <QApplication>
#include <QMainWindow>
#include <QTextEdit>
#include <QMenuBar>
#include <QMenu>
#include <QAction>
#include <QToolBar>
#include <QFile>
#include <QFileDialog>
#include <QMessageBox>

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

    // 创建主窗口和控件
    QMainWindow *mainWin = new QMainWindow;
    QTextEdit *textEdit = new QTextEdit;
    QMenuBar *menuBar = new QMenuBar;
    QMenu *fileMenu = new QMenu("File");
    QMenu *editMenu = new QMenu("Edit");
    QAction *newAction = new QAction("New");
    QAction *openAction = new QAction("Open");
    QAction *exitAction = new QAction("Exit");
    QAction *copyAction = new QAction("Copy");
    QAction *pasteAction = new QAction("Paste");
    QAction *cutAction = new QAction("Cut");
    QToolBar *toolBar = new QToolBar;
    QAction *saveAction = new QAction("Save");
    QAction *cutAction2 = new QAction("Cut");
    QAction *pasteAction2 = new QAction("Paste");

    // 添加控件到窗口中
    mainWin->setCentralWidget(textEdit);
    mainWin->setMenuBar(menuBar);
    menuBar->addMenu(fileMenu);
    menuBar->addMenu(editMenu);
    fileMenu->addAction(newAction);
    fileMenu->addAction(openAction);
    fileMenu->addAction(exitAction);
    editMenu->addAction(copyAction);
    editMenu->addAction(pasteAction);
    editMenu->addAction(cutAction);
    mainWin->addToolBar(toolBar);
    toolBar->addAction(saveAction);
    toolBar->addAction(cutAction2);
    toolBar->addAction(pasteAction2);

    // 设置窗口标题
    mainWin->setWindowTitle("Text Editor");

    // 连接Action的Click事件
    QObject::connect(newAction, &QAction::triggered, [=](){
        textEdit->clear();
    });
    QObject::connect(openAction, &QAction::triggered, [=](){
        QString filename = QFileDialog::getOpenFileName(mainWin, "Open File", ".", "Text Files(*.txt)");
        if(filename != ""){
            QFile file(filename);
            if(file.open(QIODevice::ReadOnly)){
                QTextStream stream(&file);
                textEdit->setText(stream.readAll());
                file.close();
            }else{
                QMessageBox::warning(mainWin, "Open Failed", "Failed to open file!");
            }
        }
    });
    QObject::connect(exitAction, &QAction::triggered, [=](){
        mainWin->close();
    });
    QObject::connect(copyAction, &QAction::triggered, [=](){
        textEdit->copy();
    });
    QObject::connect(pasteAction, &QAction::triggered, [=](){
        textEdit->paste();
    });
    QObject::connect(cutAction, &QAction::triggered, [=](){
        textEdit->cut();
    });
    QObject::connect(saveAction, &QAction::triggered, [=](){
        QString filename = QFileDialog::getSaveFileName(mainWin, "Save File", ".", "Text Files(*.txt)");
        if(filename != ""){
            QFile file(filename);
            if(file.open(QIODevice::WriteOnly)){
                QTextStream stream(&file);
                stream << textEdit->toPlainText();
                file.close();
            }else{
                QMessageBox::warning(mainWin, "Save Failed", "Failed to save file!");
            }
        }
    });
    QObject::connect(cutAction2, &QAction::triggered, [=](){
        textEdit->cut();
    });
    QObject::connect(pasteAction2, &QAction::triggered, [=](){
        textEdit->paste();
    });

    // 显示窗口
    mainWin->show();

    return a.exec();
}