华清 Qt day5 9月21

QT       += core gui sql network
 
/*****************************************************************/
#ifndef WIDGET_H
#define WIDGET_H
 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include "second.h"
#include 
#include 
#include 
 
 
QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE
 
class Widget : public QWidget
{
    Q_OBJECT
 
public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
 
private slots:
    void on_btn1_clicked();
 
    void on_btn2_clicked();
 
    void on_le1_cursorPositionChanged(int arg1, int arg2);
 
    void on_le2_cursorPositionChanged(int arg1, int arg2);
 
    void on_btn3_clicked();
 
signals:
    void jump();      //定义一个跳转到其他界面的信号
 
private:
    Ui::Widget *ui;
 
    Second *s1;
 
    QSqlDatabase db;   //定义一个数据库的类对象
};
#endif // WIDGET_H
 
/*****************************************************************/
#ifndef SECOND_H
#define SECOND_H
 
#include 
#include 
#include 
 
namespace Ui {
class Second;
}
 
class Second : public QDialog
{
    Q_OBJECT
 
public:
    explicit Second(QWidget *parent = nullptr);
    ~Second();
 
public slots:
    void jump_slot();     //自定义了一个槽函数
 
private slots:
    void on_pushButton_2_clicked();
    void connected_slot();
    void readyRead_slot();
 
    void on_send_clicked();
 
    void on_duankai_clicked();
 
    void disconnected_slot();
 
private:
    Ui::Second *ui;
 
    //定义一个客户端指针
    QTcpSocket *socket;
 
    //定义字符串用于接收用户名
    QString username;
};
 
#endif // SECOND_H
 
/*****************************************************************/
#include "widget.h"
#include "ui_widget.h"
 
Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    s1 = new Second;
    connect(this,&Widget::jump,s1,&Second::jump_slot); //将jump信号绑定到Second的槽函数
 
    //添加一个数据库
    if(!db.contains("id_passwd.db"))
    {
        db = QSqlDatabase::addDatabase("QSQLITE");
        db.setDatabaseName("id_passwd.db");
    }
    //打开数据库
    if(!db.open())
    {
        QMessageBox::information(this,"失败","数据库打开失败");
        return;
    }
    //创建表格，准备sql语句
    QString sql = "create table if not exists id_passwd("
                  "id varchar(10) primary key,"
                  "passwd varchar(20))";
    //准备语句执行者
    QSqlQuery querry;
    if(!querry.exec(sql))
    {
        QMessageBox::information(this,"失败","创建表失败");
    }
}
 
 
Widget::~Widget()
{
    delete ui;
}
 
//登录按钮
void Widget::on_btn1_clicked()
{
    QString username = ui->le1->text();
    QString password = ui->le2->text();
    QString sql = QString("select * from id_passwd where id = '%1' "
                          "and passwd  = '%2'").arg(username).arg(password);
    QSqlQuery q;
 
 
    //登录成功
    if (q.exec(sql)&&q.next())
    {
        QMessageBox::information(this,"登录成功","登录成功");
        //跳转到其他界面的代码
        emit jump();   //使用关键字emit发射自定义的信号
        this->hide();
    }
    else  //登录失败
    {
        //静态版
        int ret = QMessageBox::critical(this,"登录失败",
                                        "账号密码不匹配，是否重新登录",
                                        QMessageBox::Ok|QMessageBox::Cancel);
        if(ret==QMessageBox::Ok)
        {
            //清楚密码框内容
            ui->le2->clear();
        }
        else if(ret==QMessageBox::Cancel)
        {
            //关闭界面
            close();
        }
    }
}
 
//取消按钮
void Widget::on_btn2_clicked()
{
    //对象版
    QMessageBox box(QMessageBox::Question,"退出登录","是否确定退出登录？",
                    QMessageBox::Yes|QMessageBox::No,
                    this);
    int ret = box.exec();
    if(ret == QMessageBox::Yes)
    {
        //关闭界面
        close();
    }
}
 
//输入账号
void Widget::on_le1_cursorPositionChanged(int arg1, int arg2)
{
    ui->le1->setPlaceholderText("账号");
}
 
//输入密码
void Widget::on_le2_cursorPositionChanged(int arg1, int arg2)
{
    ui->le2->setPlaceholderText("密码");
    ui->le2->setEchoMode(QLineEdit::Password);
    ui->le2->setMaxLength(12);
}
 
//注册按钮对应的槽函数
void Widget::on_btn3_clicked()
{
    QString id = ui->le1->text();
    QString passwd = ui->le2->text();
 
    if(id.isEmpty()||passwd.isEmpty())
    {
        QMessageBox::information(this,"提示","填写完整账号或者密码");
        return;
    }
    //准备sql语句
    QString sql = QString("insert into id_passwd(id,passwd)"
                          "values('%1','%2')").arg(id).arg(passwd);
 
    //准备语句的执行者
    QSqlQuery querry;
    if(!querry.exec(sql))
    {
        QMessageBox::information(this,"失败","注册失败");
        return;
    }
    else
    {
        QMessageBox::information(this,"成功","注册成功");
    }
}
 
/*****************************************************************/
#include "second.h"
#include "ui_second.h"
 
Second::Second(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Second)
{
    ui->setupUi(this);
    //给客户端指针实例化对象
    socket = new QTcpSocket(this);
    connect(socket,&QTcpSocket::connected,this,&Second::connected_slot);
    connect(socket,&QTcpSocket::readyRead,this,&Second::readyRead_slot);
    connect(socket,&QTcpSocket::disconnected,this,&Second::disconnected_slot);
 
}
 
Second::~Second()
{
    delete ui;
}
 
void Second::jump_slot()
{
    this->show();     //当接收到信号，展示自己的界面
}
 
//连接按钮对应的槽函数
void Second::on_pushButton_2_clicked()
{
    //获取UI界面上的相关信息
    username = ui->le_usr->text();
    QString ip = ui->le_ip->text();
    quint16 port = ui->le_port->text().toUInt();
    //将客户端连接到指定的服务器
    socket->connectToHost(ip,port);
    //连接成功的话客户端会自动发送一个connected的信号
 
}
 
void Second::connected_slot()
{
    QMessageBox::information(this,"成功","连接服务器成功");
    QString msg = username + ":进入聊天室";
    socket->write(msg.toLocal8Bit());         //将数据发给服务器
}
 
void Second::readyRead_slot()
{
    //读取服务器发来的信息
    QByteArray msg = socket->readAll();
    //将数据展示到界面
    ui->listWidget->addItem(QString::fromLocal8Bit(msg));
}
 
//发送按钮对应的槽函数
void Second::on_send_clicked()
{
    //读取UI界面中输入的内容
    QString msg = username + ": " + ui->text->text();
    //发送给服务器
    socket->write(msg.toLocal8Bit());
    ui->text->clear();
}
 
//断开按钮对应的槽函数
void Second::on_duankai_clicked()
{
    QString msg = username + " 离开服务器";
    socket->write(msg.toLocal8Bit());
 
    //断开连接
    socket->disconnectFromHost();
    //此时，客户端会自动发射一个disconnected信号
}
 
void Second::disconnected_slot()
{
    QMessageBox::information(this,"提示","退出成功");
}

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