QT作业5 - 技术栈

1、聊天室

服务器端

cpp 复制代码

//头文件
#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QTcpServer>
#include <QTcpSocket>
#include <QList>
#include <QListWidget>
#include <QMessageBox>
#include <QDebug>
#include <QLineEdit>
#include <QPushButton>
QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT
    QListWidget *wid;
    QLineEdit *Edit;
    QPushButton *Btn;

public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
private slots:
    void on_clicked();
    void newConnect_slot();
    void readyRead_slot();

private:
    Ui::Widget *ui;
    QTcpServer *ser;
    QList<QTcpSocket*> cliList;
};
#endif // WIDGET_H


//源文件
#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    this->wid=new QListWidget(this);
    wid->resize(800,500);
    wid->setFixedSize(760,400);
    wid->move(20,20);

    this->Edit=new QLineEdit(this);
    Edit->resize(500,50);
    Edit->move(20,440);
    this->Btn=new QPushButton("启动",this);
    Btn->resize(200,50);
    Btn->move(580,440);
    ser=new QTcpServer(this);
    QObject::connect(Btn,&QPushButton::clicked,this,&Widget::on_clicked);
}

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

void Widget::on_clicked()
{
    if(this->Btn->text()=="启动")
    {
        quint16 port=this->Edit->text().toUInt();

            if(ser->listen(QHostAddress::Any, port) == true)
            {
                QMessageBox::information(this, "成功", "服务器启动成功");
            }else
            {
                QMessageBox::information(this, "失败", "服务器启动失败");
            }


            connect(ser, &QTcpServer::newConnection, this, &Widget::newConnect_slot);




            //将文本内容更改成 关闭
            this->Btn->setText("关闭");
        }else
        {
            //关闭服务器
            ser->close();        //关闭监听


            //将文件内容更改成 启动
            this->Btn->setText("启动");
        }
}
void Widget::newConnect_slot()
{
    qDebug () <<"有新客户端发来连接请求了，请尽快处理";
    //获取最新连接的客户端套接字,并将最新连接的套接字地址返回
    QTcpSocket* socket = ser->nextPendingConnection();


    //将该客户端套接字放入到客户端容器中
    cliList.append(socket);


    //当有客户端向服务器发来数据时，当前这个客户端套接字就会自动发射一个readyRead信号
    //我们可以将该信号连接到对应的信号处理函数中，处理相关数据
    connect(socket, &QTcpSocket::readyRead, this, &Widget::readyRead_slot);


}
void Widget::readyRead_slot()
{
    //判断客户端容器中，是否有已经退出的客户端，或无效的客户端，如果有，将其进行移除
    for(int i=0; i<cliList.length(); i++)
    {
        if(cliList[i]->state() == QTcpSocket::UnconnectedState)
        {//功能：判断当前套接字的状态
           //参数：无
           //返回值：readyRead_slot表示无效的套接字
           cliList.removeAt(i);           //将下标为i的客户端套接字从容器中移除
        }
    }


    //再将客户端容器遍历一遍，判断哪个客户端中有数据待读
    for(int i=0; i<cliList.length(); i++)
    {
        if(cliList[i]->bytesAvailable() != 0)
        {
            //功能：获取当前套接字中待读数据的个数
            //参数：无
            //返回值：返回套接字中待读数据的个数，如果为0，表示没有数据可读
            //如果不等于0，表示有数据可读，可以使用readAll读取数据
            QByteArray msg = cliList[i]->readAll();


            //将该消息，展示到ui界面上
            this->wid->addItem(QString::fromLocal8Bit(msg));


            //将该消息转发给所有客户端
            for(int j=0; j<cliList.length(); j++)
            {
                if(i!=j)       
                {
                    cliList[j]->write(msg);
                }
            }
        }
    }
}

客户端

cpp 复制代码

头文件：
#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QTcpSocket>
#include <QMessageBox>
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 connnected_slot();
    void readyRead_slot();
    void disconnectes_slot();
    void on_pushButton_clicked();

    void on_connectBtn_clicked();

private:
    Ui::Widget *ui;
    QTcpSocket *cli;
    QString userName;
};
#endif // WIDGET_H


源文件：
#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    cli=new QTcpSocket(this);
    connect(cli,&QTcpSocket::connected,this,&Widget::connnected_slot);
    connect(cli,&QTcpSocket::readyRead,this,&Widget::readyRead_slot);
    connect(cli,&QTcpSocket::disconnected,this,&Widget::disconnectes_slot);
}

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


void Widget::connnected_slot()
{
    QMessageBox::information(this,"连接","连接成功！");
}


void Widget::readyRead_slot()
{
    //将客户端套接字中的消息读取出来
    QByteArray msg=cli->readAll();
    ui->listWidget->addItem(msg);
}
void Widget::disconnectes_slot()
{
    QMessageBox::information(this,"断开","断开服务器");
}

void Widget::on_pushButton_clicked()
{
    QString msg=ui->lineEdit->text();
    cli->write(msg.toLocal8Bit());
    ui->lineEdit->clear();
    QListWidgetItem *item=new QListWidgetItem(msg);
    item->setTextAlignment(Qt::AlignRight);
    ui->listWidget->addItem(item);
}

void Widget::on_connectBtn_clicked()
{
    if(ui->connectBtn->text()=="连接服务器")
    {
        userName = ui->userNameEdit->text();
        QString ip=ui->ipEdit->text();
        quint16 port =ui->portEdit->text().toUInt();
        cli->connectToHost(ip,port);

        ui->connectBtn->setText("断开服务器");
    }else {
        cli->disconnectFromHost();
        ui->connectBtn->setText("连接服务器");
    }
}

2、完善数据库管理系统

cpp 复制代码

头文件：
#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QSqlDatabase>
#include <QSqlQuery>
#include <QSqlRecord>
#include <QMessageBox>
#include <QDebug>
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_addBtn_clicked();

    void on_searchBtn_clicked();

private:
    Ui::Widget *ui;
    QSqlDatabase db;
};
#endif // WIDGET_H

源文件
#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    if(!db.contains("mydb.db"))
    {
        db=QSqlDatabase::addDatabase("QSQLITE");
        db.setDatabaseName("mydb.db");
    }
    if(!db.open())
    {
        QMessageBox::information(this,"失败","数据打开失败");
        return;
    }
    QString sql="create table if not exists Stu(numb int,name char,sex char,score double)";
    QSqlQuery query;
    if(!query.exec(sql))
    {
        QMessageBox::information(this,"提示","创建数据表失败");

        return;
    } else
        {
            QMessageBox::information(this,"提示","创建数据表成功");
            return;
        }
}

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

void Widget::on_addBtn_clicked()
{
    int ui_numb=ui->numbEdit->text().toUInt();
    QString ui_name=ui->nameEdit->text();
    QString ui_sex=ui->sexEdit->text();
    double ui_score=ui->scoreEdit->text().toDouble();
    if(ui_sex==NULL||ui_numb==0||ui_score==0||ui_name==NULL)
    {
        QMessageBox::information(this,"提示","请将信息填写完整");
        return;
    }else
    {

    }
    //准备sql语句
    QString sql=QString("insert into Stu values(%1,'%2','%3',%4)").arg(ui_numb).arg(ui_name).arg(ui_sex).arg(ui_score);
    QSqlQuery query;
    if(!query.exec(sql))
    {
        QMessageBox::information(this,"提示","创建数据表失败");

        return;
    }else
    {
        QMessageBox::information(this,"提示","创建数据表成功");
        return;
    }
}
//查找按钮对应的槽函数
void Widget::on_searchBtn_clicked()
{
    QString sql;
    if(ui->nameEdit->text()==NULL)
    {
        sql="select * from Stu";
    }else
    {
        sql=QString("select %1 from Stu").arg(ui->nameEdit->text());
    }
    QSqlQuery query;
    if(!query.exec(sql))
    {
        QMessageBox::information(this,"提示","查询失败");
        return;
    }

    int i=0;
    while(query.next())
    {
        //qDebug()<<query.record();
        for(int j=0;j<query.record().count();j++)
        {
            QTableWidgetItem *item=new QTableWidgetItem(query.record().value(j).toString());
            item->setTextAlignment(Qt::AlignCenter);
            ui->tableWidget->setItem(i,j,item);
        }
        i++;
    }
}

3、思维导图