文件传输软件

桥段、

<div id="cnblogs_post_body">  首先我们明确，这是一个局域网文件传输工具，具体功能实现，用网络编程，同样要设置端口号，IP地址等，这个软件已经用起来比U盘方便跟多，比平常U盘等移动存储工具的传输速率高。
传输文件数据时候，设置文件头包含信息，包括文件大小，文件名，防止出错在文件头加了个标示，读取到标识才开始传文件数据，还需要设置缓冲区，缓冲区传文件开始之前先清空。
对于文件传输来说，相当于数据先进缓冲区，之后在从缓冲区去文件数据，这样的话在接收端看到的进度条效果会比发送端进度条延后一些。


发送端

接收端


选择打开文件。

等待确认。


接收端确认



确认接收文件




接收成功。



F盘已经有文件存在。

发送端：
<div class="cnblogs_code">#include "testclient.h"#include "ui_testclient.h"#include <string>TestClient::TestClient(QWidget *parent) :    QWidget(parent),    ui(new Ui::TestClient){    ui->setupUi(this);    socket = new QTcpSocket();    loadSize = qint64(4*1024);    this->onReset();    connect(socket,SIGNAL(connected()),this,SLOT(startTransfer()));    connect(socket,SIGNAL(bytesWritten(qint64)),this,SLOT(updateProgress(qint64)));    connect(socket,SIGNAL(error(QAbstractSocket::SocketError)),this,SLOT(displayError(QAbstractSocket::SocketError)));    connect(ui->pushButton_file,SIGNAL(clicked()),this,SLOT(openFile()));    connect(ui->pushButton_send,SIGNAL(clicked()),this,SLOT(onSend()));    connect(ui->pushButton_abort,SIGNAL(clicked()),this,SLOT(onAbort()));    connect(socket,SIGNAL(readyRead()),this,SLOT(onRead()));}TestClient::~TestClient(){    delete ui;    delete socket;    delete localFile;}void TestClient::openFile(){    fileName = QFileDialog::getOpenFileName(this);    if(!fileName.isEmpty())    {        localFile = new QFile(fileName);        ui->pushButton_send->setEnabled(true);        ui->pushButton_file->setDisabled(true);        ui->pushButton_abort->setEnabled(true);        ui->textEdit->append(tr("Open %1 success.").arg(fileName));    }}void TestClient::onSend(){    if (0 == flag)    {        flag = 0;        ui->progressBar->reset();        ui->pushButton_send->setDisabled(true);        ui->pushButton_send->setText(tr("Pause"));        bytesWritten = 0;        ui->textEdit->append(tr("Connecting to host."));        socket->connectToHost(ui->lineEdit_host->text(),ui->lineEdit_port->text().toInt());        if(!socket->waitForConnected(3000))        {            ui->textEdit->append(tr("Connect timed out."));            return;        }    }    else if (1 == flag)    {        flag = 2;        ui->pushButton_send->setText(tr("Continue"));    }    else    {        flag = 1;        ui->pushButton_send->setText(tr("Pause"));        ui->textEdit->append(tr("Send %1 continue.").arg(currentFileName));        this->updateProgress(0);    }}void TestClient::onRead(){    int length = socket->bytesAvailable();    char readBuf[10];    memset(readBuf,0,sizeof(readBuf));    socket->read(readBuf,length);    //ui->textEdit->append(tr("Read %1 from host.").arg(readBuf));    if (0 == strcmp(readBuf,"yes"))    {        flag = 1;        ui->textEdit->append(tr("Host has comfirmed. Sending %1.").arg(currentFileName));        ui->pushButton_send->setEnabled(true);        this->updateProgress(0);    }    else    {        socket->abort();        localFile->close();        this->onReset();        ui->textEdit->append(tr("Send %1 failed. Host denied transfer.").arg(currentFileName));    }}void TestClient::onAbort(){    this->onReset();    ui->textEdit->append(tr("Send %1 abort.").arg(currentFileName));    socket->abort();    localFile->close();}void TestClient::onReset(){    ui->progressBar->reset();    ui->pushButton_send->setText(tr("Send"));    ui->pushButton_send->setDisabled(true);    ui->pushButton_abort->setDisabled(true);    ui->pushButton_file->setEnabled(true);    flag = 0;    totalBytes = 0;    bytesWritten = 0;    bytesToWrite = 0;}void TestClient::startTransfer(){    if(!localFile->open(QFile::ReadOnly))    {        ui->textEdit->append(tr("Open file failed."));        return;    }    totalBytes = localFile->size();    QDataStream sendOut(&outBlock,QIODevice::WriteOnly);    sendOut.setVersion(QDataStream::Qt_4_6);    currentFileName = fileName.right(fileName.size() - fileName.lastIndexOf('/')-1);    sendOut << qint64(0) << qint64(0) << currentFileName;    totalBytes += outBlock.size();    sendOut.device()->seek(0);    sendOut<<totalBytes<<qint64((outBlock.size() - sizeof(qint64)*2));    socket->write(outBlock);    socket->flush();//    bytesWritten += socket->write(outBlock);    bytesToWrite = totalBytes - bytesWritten;    ui->progressBar->setMaximum(totalBytes);    ui->textEdit->append(tr("Conected, watting for comformation."));    outBlock.resize(0);    ui->pushButton_abort->setEnabled(true);    ui->textEdit->append(tr("%1 of %2 . done %3 left").arg(bytesWritten).arg(totalBytes).arg(bytesToWrite));}void TestClient::updateProgress(qint64 numBytes){    bytesWritten += numBytes;    if (1 == flag)    {        if(bytesToWrite > 0)        {            outBlock = localFile->read(qMin(bytesToWrite,loadSize));            bytesToWrite -= socket->write(outBlock);            outBlock.resize(0);        }        else        {            ui->textEdit->append(tr("Finish sending %1 of %2 . done %3 left").arg(bytesWritten).arg(totalBytes).arg(bytesToWrite));        }        if(bytesWritten == totalBytes)        {            this->onReset();            ui->textEdit->append(tr("Send file %1 success.").arg(currentFileName));            localFile->close();            //socket->close();        }    }    else    {        ui->textEdit->append(tr("Sending %1 puased.").arg(currentFileName));    }    ui->progressBar->setValue(bytesWritten);}void TestClient::displayError(QAbstractSocket::SocketError){    if(bytesWritten != totalBytes)    {        this->onReset();        socket->abort();        localFile->close();        ui->textEdit->append(tr("Send %1 failed. Error: %2 .").arg(currentFileName).arg(socket->errorString()));    }}