简易版QQ？Qt也可以实现！（一）

class QtClient : public QWidget
{
  Q_OBJECT
public:
  QtClient(QWidget *parent = 0, Qt::WFlags flags = 0);
  ~QtClient();

  void initTCP();
  void newConnect();

  private slots:
    ////连接服务器
    void connectServer();
    ////与服务器断开连接
    void disconnectServer();
    ////接收服务器发送的数据
    void receiveData();  
    ////向服务器发送数据
    void sendData();

    ////浏览文件
    void selectFile();
    ////发送文件
    void sendFile();
    ////更新文件发送进度
    void updateFileProgress(qint64);
    ////更新文件接收进度
    void updateFileProgress();

private:
  Ui::QtClientClass ui;
  QTcpSocket *tcpSocket;
  QTcpSocket *fileSocket;

  ///文件传送
  QFile *localFile;
  ///文件大小
  qint64 totalBytes;      //文件总字节数
  qint64 bytesWritten;    //已发送的字节数
  qint64 bytestoWrite;    //尚未发送的字节数
  qint64 filenameSize;    //文件名字的字节数
  qint64 bytesReceived;   //接收的字节数
  ///每次发送数据大小
  qint64 perDataSize;
  QString filename;
  ///数据缓冲区
  QByteArray inBlock;
  QByteArray outBlock;

  ////系统时间
  QDateTime current_date_time;
  QString str_date_time;
};

#include "qtclient.h"

QtClient::QtClient(QWidget *parent, Qt::WFlags flags)
  : QWidget(parent, flags)
{
  ui.setupUi(this);
  this->initTCP();

  /////文件传送相关变量初始化
  ///每次发送数据大小为64kb
  perDataSize = 64*1024;
  totalBytes = 0;
  bytestoWrite = 0;
  bytesWritten = 0;
  bytesReceived = 0;
  filenameSize = 0;

  connect(this->ui.pushButton_openFile,SIGNAL(clicked()),this,SLOT(selectFile()));
  connect(this->ui.pushButton_sendFile,SIGNAL(clicked()),this,SLOT(sendFile()));
}

QtClient::~QtClient()
{
}

void QtClient::initTCP()
{
  this->tcpSocket = new QTcpSocket(this);
  connect(ui.pushButton_connect,SIGNAL(clicked()),this,SLOT(connectServer()));
  connect(ui.pushButton_disconnect,SIGNAL(clicked()),this,SLOT(disconnectServer()));
  connect(ui.pushButton_send,SIGNAL(clicked()),this,SLOT(sendData()));
}

void QtClient::connectServer()
{
  tcpSocket->abort();
  tcpSocket->connectToHost("127.0.0.1",6666);
  connect(tcpSocket,SIGNAL(readyRead()),this,SLOT(receiveData()));
}

void QtClient::disconnectServer()
{
  //这里不做实现了，大家自己定义吧O(∩_∩)O哈哈~
}

void QtClient::receiveData()
{
  /////获取当前时间
  current_date_time = QDateTime::currentDateTime();
  str_date_time = current_date_time.toString("yyyy-MM-dd hh:mm:ss")+"\n";
  ////接收数据
  QString str = tcpSocket->readAll();
  ////显示
  str = "Server "+str_date_time+str;
  this->ui.textEdit->append(str);
}

void QtClient::sendData()
{
  ////发送数据
  QString str = ui.lineEdit->text();
  this->tcpSocket->write(ui.lineEdit->text().toLatin1());
  ////显示
  current_date_time = QDateTime::currentDateTime();
  str_date_time = current_date_time.toString("yyyy-MM-dd hh:mm:ss");
  str = "You "+str_date_time+"\n"+str;
  ui.textEdit->append(str);
}

void QtClient::selectFile()
{
  this->fileSocket = new QTcpSocket(this);
  fileSocket->abort();
  fileSocket->connectToHost("127.0.0.1",8888);
  ////文件传送进度更新
  connect(fileSocket,SIGNAL(bytesWritten(qint64)),this,SLOT(updateFileProgress(qint64)));
  connect(fileSocket,SIGNAL(readyRead()),this,SLOT(updateFileProgress()));

  this->ui.progressBar->setValue(0);
  this->filename = QFileDialog::getOpenFileName(this,"Open a file","/","files (*)");
  ui.lineEdit_filename->setText(filename);
}