QTcpSocket使用QDataStream发送和保存图片文件

àì夳堔傛蜴生んèń 2022-01-30 08:59 419阅读 0赞

# QTcpSocket使用QDataStream发送和保存图片文件 #

## 图片文件 ##

现在遇到的问题是writeRawData()读取大文件时程序崩溃，思路是分多次进行读取和发送。

发送端

qDebug()<<"start to find pix"<<endl;

QImage pic("D:/svn//timg.jpg");

if(pic.isNull())\{

qDebug()<<"can not find pix"<<endl;

return ;

else\{

qDebug()<<"succeed tot find pix"<<endl;

QByteArray block; //用于暂存我们要发送的数据

QDataStream out(&block,QIODevice::ReadWrite);

out.setVersion(QDataStream::Qt\_4\_6);

qDebug()<<"pic.size:"<<pic.size()<<endl;

//  out<<tr("hello Tcp!!!");

out<<pic;

out.device()->seek(0);

QTcpSocket \*clientConnection = tcpServer->nextPendingConnection();

clientConnection->write(block);

接收端

/\*全局变量

\*QImage image;

\*QByteArray res\_block;

\*/

connect(tcpSocket, &QTcpSocket::readyRead,

\[=\]()\{

//从通信套接字中取出内容

QByteArray array = tcpSocket->readAll();

qDebug()<<"size:"<<array.size()<<endl;

res\_block=res\_block+array;

qDebug()<<"res\_block size:"<<res\_block.size()<<endl;

QDataStream image\_stream(&res\_block,QIODevice::ReadWrite);

image\_stream>>image;

\});

## 任意文件(无法读取大文件) ##

发送端

QFile file("D:/svn/UVSScure/Client/build/jpeg\_2\_128.jpg");

int flag=file.open(QIODevice::ReadOnly);

QDataStream in(&file);

QFileInfo fileInfo("D:/svn/UVSScure/Client/build/jpeg\_2\_128.jpg");

QTcpSocket \*clientConnection = tcpServer->nextPendingConnection();

char datRawArray\[fileInfo.size()\];

in.readRawData(datRawArray, fileInfo.size());

QByteArray block(datRawArray,fileInfo.size());

quint32 write\_len = clientConnection->write(block);

接收端

/\*全局变量

\*QDataStream file\_stream;

\*QByteArray  res\_block;

\*QFile       file;

\*/

file.setFileName("D:/svn/UVSScure/Client/build/image\_res.jpg");

file.open(QIODevice::ReadWrite);

file\_stream.setDevice(&file);

connect(tcpSocket, &QTcpSocket::readyRead,

\[=\]()\{

//从通信套接字中取出内容

QByteArray array = tcpSocket->readAll();

qDebug()<<"size:"<<array.size()<<endl;

res\_block=res\_block+array;

qDebug()<<"res\_block size:"<<res\_block.size()<<endl;

QDataStream image\_stream(&res\_block,QIODevice::ReadWrite);

file\_stream.writeRawData(res\_block,res\_block.size();//这个函数放在ondisconnect中

\});

## TCP收发大文件 ##

1. TCP分多次发送读取和接收大文件

QFile file("D:/svn/UVSScure/Client/build/jpeg\_2\_128.jpg");

int flag=file.open(QIODevice::ReadOnly);

QDataStream in(&file);

QFileInfo fileInfo("D:/svn/UVSScure/Client/build/jpeg\_2\_128.jpg");

QTcpSocket \*clientConnection = tcpServer->nextPendingConnection();

connect(clientConnection,SIGNAL(disconnected()),clientConnection,

SLOT(deleteLater()));

int file\_size;

file\_size=fileInfo.size();

connect(clientConnection,&QTcpSocket::bytesWritten,\[=\](qint64 num)\{

static int total\_size=0;

total\_size+=num;

qDebug()<<"num:"<<num<<endl;

qDebug()<<"total\_size:"<<total\_size<<endl;

qDebug()<<"file\_size:"<<file\_size<<endl;

if(total\_size>file\_size)\{

clientConnection->disconnectFromHost();

qDebug()<<"wrirte finished!"<<endl;

total\_size=0;

\});

int buffer\_size=65535;

char datRawArray\[buffer\_size\];

qDebug()<<"nomal"<<fileInfo.size()<<endl;

while(!in.atEnd())\{

in.readRawData(datRawArray, buffer\_size);

QByteArray block(datRawArray,buffer\_size);

qDebug()<<"block\_size:"<<block.size()<<endl;

quint32 write\_len = clientConnection->write(block);

qDebug("write len:%d",write\_len);

2. TCP接收文件

connect(tcpSocket,SIGNAL(disconnected()),this,SLOT(ondisconnect()));

file.setFileName("D:/svn/UVSScure/Client/build/image\_res.jpg");

file.open(QIODevice::ReadWrite);

file\_stream.setDevice(&file);

connect(tcpSocket, &QTcpSocket::readyRead,

\[=\]()\{

//从通信套接字中取出内容

QByteArray array = tcpSocket->readAll();

qDebug()<<"size:"<<array.size()<<endl;

res\_block=res\_block+array;

qDebug()<<"res\_block size:"<<res\_block.size()<<endl;

\});

void ondisconnect()\{

if(file\_stream.writeRawData(res\_block,res\_block.size()))\{

qDebug()<<"write csv file successful"<<endl;

else\{

qDebug()<<"fail to save csv file"<<endl;

file.close();

qDebug()<<"file closed !"<<endl;

## TCP一次性发送发大文件 ##

QFile file("D:/svn/UVSScure/Client/build/jpeg\_2\_128.jpg");

int flag=file.open(QIODevice::ReadOnly);

QDataStream in(&file);

QFileInfo fileInfo("D:/svn/UVSScure/Client/build/jpeg\_2\_128.jpg");

QTcpSocket \*clientConnection = tcpServer->nextPendingConnection();

QByteArray total\_file;

connect(clientConnection,SIGNAL(disconnected()),clientConnection,

SLOT(deleteLater()));

int file\_size;

file\_size=fileInfo.size();

connect(clientConnection,&QTcpSocket::bytesWritten,\[=\](qint64 num)\{

clientConnection->disconnectFromHost();

\});

int buffer\_size=65535;

char datRawArray\[buffer\_size\];

qDebug()<<"nomal"<<fileInfo.size()<<endl;

while(!in.atEnd())\{

in.readRawData(datRawArray, buffer\_size);

QByteArray block(datRawArray,buffer\_size);

qDebug()<<"block\_size:"<<block.size()<<endl;

total\_file+=block

quint32 write\_len = clientConnection->write(total\_file);

qDebug("write len:%d",write\_len);

QTcpSocket使用QDataStream发送和保存图片文件

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