- private:
- QTcpSocket *tcpClient;
- QFile *localFile; //要發送的文件
- qint64 totalBytes; //數據總大小
- qint64 bytesWritten; //已經發送數據大小
- qint64 bytesToWrite; //剩餘數據大小
- qint64 loadSize; //每次發送數據的大小
- QString fileName; //保存文件路徑
- QByteArray outBlock; //數據緩衝區,即存放每次要發送的數據
- private slots:
- void send(); //連接服務器
- void startTransfer(); //發送文件大小等信息
- void updateClientProgress(qint64); //發送數據,更新進度條
- void displayError(QAbstractSocket::SocketError); //顯示錯誤
- void openFile(); //打開文件
- Widget::Widget(QWidget *parent) :
- QWidget(parent),
- ui(new Ui::Widget)
- {
- ui->setupUi(this);
- loadSize = 4*1024;
- totalBytes = 0;
- bytesWritten = 0;
- bytesToWrite = 0;
- tcpClient = new QTcpSocket(this);
- connect(tcpClient,SIGNAL(connected()),this,SLOT(startTransfer()));
- //當連接服務器成功時,發出connected()信號,我們開始傳送文件
- connect(tcpClient,SIGNAL(bytesWritten(qint64)),this,SLOT(updateClientProgress(qint64)));
- //當有數據發送成功時,我們更新進度條
- connect(tcpClient,SIGNAL(error(QAbstractSocket::SocketError)),this,SLOT(displayError(QAbstractSocket::SocketError)));
- ui->sendButton->setEnabled(false);
- ui->hostLineEdit->setText("192.168.1.100");
- ui->portLineEdit->setText("6666");
- }
- void Widget::openFile() //打開文件
- {
- fileName = QFileDialog::getOpenFileName(this);
- if(!fileName.isEmpty())
- {
- ui->sendButton->setEnabled(true);
- ui->clientStatusLabel->setText(tr("打開文件 %1 成功!").arg(fileName));
- }
- }
- void Widget::send() //連接到服務器,執行發送
- {
- ui->sendButton->setEnabled(false);
- bytesWritten = 0;
- //初始化已發送字節爲0
- ui->clientStatusLabel->setText(tr("連接中…"));
- tcpClient->connectToHost(QHostAddress(ui->hostLineEdit->text()),ui->portLineEdit->text().toInt());//連接
- }
- void Widget::on_openButton_clicked() //打開按鈕
- {
- openFile();
- }
- void Widget::on_sendButton_clicked() //發送按鈕
- {
- send();
- }
- void Widget::startTransfer() //實現文件大小等信息的發送
- {
- localFile = new QFile(fileName);
- if(!localFile->open(QFile::ReadOnly))
- {
- qDebug() << "open file error!";
- return;
- }
- totalBytes = localFile->size();
- //文件總大小
- QDataStream sendOut(&outBlock,QIODevice::WriteOnly);
- sendOut.setVersion(QDataStream::Qt_4_6);
- QString currentFileName = fileName.right(fileName.size() - fileName.lastIndexOf('/')-1);
- sendOut << qint64(0) << qint64(0) << currentFileName;
- //依次寫入總大小信息空間,文件名大小信息空間,文件名---僅是文件名不含路徑,沒必要含路徑
- totalBytes += outBlock.size();
- //這裏的總大小是文件名大小等信息和實際文件大小的總和
- sendOut.device()->seek(0);
- sendOut<<totalBytes<<qint64((outBlock.size() - sizeof(qint64)*2));
- //totalBytes是文件總大小,即兩個quint64的大小+文件名+文件實際內容的大小
- //qint64((outBlock.size() - sizeof(qint64)*2))得到的是文件名大小
- bytesToWrite = totalBytes - tcpClient->write(outBlock);
- //發送完頭數據後剩餘數據的大小,即文件實際內容的大小
- ui->clientStatusLabel->setText(tr("已連接"));
- outBlock.resize(0);
- }
- void Widget::updateClientProgress(qint64 numBytes) //更新進度條,實現文件的傳送
- {
- bytesWritten += (int)numBytes;
- //已經發送數據的大小
- if(bytesToWrite > 0) //如果已經發送了數據
- {
- outBlock = localFile->read(qMin(bytesToWrite,loadSize));
- //每次發送loadSize大小的數據,這裏設置爲4KB,如果剩餘的數據不足4KB,
- //就發送剩餘數據的大小
- bytesToWrite -= (int)tcpClient->write(outBlock);
- //發送完一次數據後還剩餘數據的大小
- outBlock.resize(0);
- //清空發送緩衝區
- }
- else
- {
- localFile->close(); //如果沒有發送任何數據,則關閉文件
- }
- ui->clientProgressBar->setMaximum(totalBytes);
- ui->clientProgressBar->setValue(bytesWritten);
- //更新進度條
- if(bytesWritten == totalBytes) //發送完畢
- {
- ui->clientStatusLabel->setText(tr("傳送文件 %1 成功").arg(fileName));
- localFile->close();
- tcpClient->close();
- }
- }
- void Widget::displayError(QAbstractSocket::SocketError) //顯示錯誤
- {
- qDebug() << tcpClient->errorString();
- tcpClient->close();
- ui->clientProgressBar->reset();
- ui->clientStatusLabel->setText(tr("客戶端就緒"));
- ui->sendButton->setEnabled(true);
- }
流程:
1創建tcpSocket ,tcpClient= new QTcpSocket(this);
2.關聯信號connected和槽函數startTransfer,connect(tcpClient,SIGNAL(connected()),this,SLOT(startTransfer()));其中信號connected在連接服務器成功(即本客戶端執行 tcpClient->connectToHost,得到服務器的成功響應)時發射,此時執行startTransfer開始傳輸文件頭數據
3.關聯信號bytesWritten和槽函數updateClientProgress,connect(tcpClient,SIGNAL(bytesWritten(qint64)),this,SLOT(updateClientProgress(qint64)));其中信號bytesWritten在當有數據發送成功時(即本客戶端執行 tcpClient->write(outBlock);服務器的成功收outBlock時)時發射,此時執行updateClientProgress來更新進度條並接着發送剩餘數據
4.連接到某個ip的某個端口,tcpClient->connectToHost(QHostAddress(ui->hostLineEdit->text()),ui->portLineEdit->text().toInt())
5.實現槽函數startTransfer,開始傳輸文件頭數據
5.實現槽函數updateClientProgress,更新進度條,並接着發送剩餘數據
其中發送的文件頭包括一個quint64(記錄文件總大小,包括sizeof(quint64)+sizeof(quint64)+文件名+文件實際內容),一個quint64(記錄文件名大小),一個文件名不含路徑,一個文件實際內容
tcpReceiver
- private:
- QTcpServer tcpServer;
- QTcpSocket *tcpServerConnection;
- qint64 totalBytes; //存放總大小信息
- qint64 bytesReceived; //已收到數據的大小
- qint64 fileNameSize; //文件名的大小信息
- QString fileName; //存放文件名
- QFile *localFile; //本地文件
- QByteArray inBlock; //數據緩衝區
- private slots:
- void start(); //開始監聽
- void acceptConnection(); //建立連接
- void updateServerProgress(); //更新進度條,接收數據
- void displayError(QAbstractSocket::SocketError socketError);
- Widget::Widget(QWidget *parent) :
- QWidget(parent),
- ui(new Ui::Widget)
- {
- ui->setupUi(this);
- totalBytes = 0;
- bytesReceived = 0;
- fileNameSize = 0;
- connect(&tcpServer,SIGNAL(newConnection()),this,SLOT(acceptConnection()));
- //當發現新連接時發出newConnection()信號
- }
- void Widget::start() //開始監聽
- {
- ui->startButton->setEnabled(false);
- bytesReceived =0;
- if(!tcpServer.listen(QHostAddress("192.168.1.100"),6666))
- {
- qDebug() << tcpServer.errorString();
- close();
- return;
- }
- ui->serverStatusLabel->setText(tr("監聽"));
- }
- void Widget::on_startButton_clicked() //開始監聽按鈕
- {
- start();
- }
- void Widget::acceptConnection() //接受連接
- {
- tcpServerConnection = tcpServer.nextPendingConnection();
- connect(tcpServerConnection,SIGNAL(readyRead()),this,SLOT(updateServerProgress()));
- connect(tcpServerConnection,SIGNAL(error(QAbstractSocket::SocketError)),this,SLOT(displayError(QAbstractSocket::SocketError)));
- ui->serverStatusLabel->setText(tr("接受連接"));
- tcpServer.close();
- }
- void Widget::updateServerProgress() //更新進度條,接收數據
- {
- QDataStream in(tcpServerConnection);
- in.setVersion(QDataStream::Qt_4_6);
- if(bytesReceived <= sizeof(qint64)*2)
- { //如果接收到的數據小於16個字節,那麼是剛開始接收數據,我們保存到//來的頭文件信息
- if((tcpServerConnection->bytesAvailable() >= sizeof(qint64)*2)&& (fileNameSize == 0))
- { //接收數據總大小信息和文件名大小信息
- in >> totalBytes >> fileNameSize;
- bytesReceived += sizeof(qint64) * 2;
- }
- if((tcpServerConnection->bytesAvailable() >= fileNameSize)
- && (fileNameSize != 0))
- { //接收文件名,並建立文件
- in >> fileName;
- ui->serverStatusLabel->setText(tr("接收文件 %1 …").arg(fileName));
- bytesReceived += fileNameSize;
- localFile = new QFile(fileName);
- if(!localFile->open(QFile::WriteOnly))
- {
- qDebug() << "open file error!";
- return;
- }
- }
- else return;
- }
- if(bytesReceived < totalBytes)
- { //如果接收的數據小於總數據,那麼寫入文件
- bytesReceived += tcpServerConnection->bytesAvailable();
- inBlock = tcpServerConnection->readAll();
- localFile->write(inBlock);
- inBlock.resize(0);
- }
- ui->serverProgressBar->setMaximum(totalBytes);
- ui->serverProgressBar->setValue(bytesReceived);
- //更新進度條
- if(bytesReceived == totalBytes)
- { //接收數據完成時
- tcpServerConnection->close();
- localFile->close();
- ui->startButton->setEnabled(true);
- ui->serverStatusLabel->setText(tr("接收文件 %1 成功!").arg(fileName));
- }
- }
- void Widget::displayError(QAbstractSocket::SocketError) //錯誤處理
- {
- qDebug() << tcpServerConnection->errorString();
- tcpServerConnection->close();
- ui->serverProgressBar->reset();
- ui->serverStatusLabel->setText(tr("服務端就緒"));
- ui->startButton->setEnabled(true);
- }
流程
1.創建 QTcpServer tcpServer;使之監聽本機的某個端口,tcpServer.listen(QHostAddress("192.168.1.100"),6666)
2,關聯信號newConnection和槽函數sendMessage, connect(&tcpServer,SIGNAL(newConnection()),this,SLOT(acceptConnection()));其中信號newConnection在有客戶端的連接請求(即客戶端執行tcpSocket->connectToHost)時發射,此時執行acceptConnection,
3.實現槽函數acceptConnection,在裏面
從tcpServer取得已經建立但掛起的QTcpSocket連接
tcpServerConnection = tcpServer.nextPendingConnection();
並關聯信號readyRead和槽函數updateServerProgress,
connect(tcpServerConnection,SIGNAL(readyRead()),this,SLOT(updateServerProgress()));其中信號readyRead在有新的數據到達時發射,此時執行updateServerProgress函數把接收到的數據保存到文件,並更新進度條
4.實現槽函數updateServerProgress
從上篇和此篇可看出基於客戶和服務器的tcp編程:
需要在服務器端有QTcpServer監視某個端口,在客戶端使用QTcpSocket發起連接,然後在服務器端獲取連接QTcpSocket,然後雙方就使用QTcpSocket提供的方法來互發數據其中,
發送方使用 QByteArray block; clientConnection->write(block);發送數據,使用bytesWritten信號得知數據已經發送完成
接收方使用readyRead信號得知有數據到達,使用 QDataStream in(tcpSocket); in >> message;