下面是代码 ：
用QT 写了个发送和接受图片，发现能正常显示的远小于不能显示的，不知哪里出问题
我每次用UDP发送128B，图片大小为30K，直到发送完成。接受端那里出现丢包现象，偶而会成功一次
请高人帮我看看，下面是代码：
发送端：
connect(ui->sendButton,SIGNAL(clicked()),
this,SLOT(sendDatagram()));
connect(udpSocket,SIGNAL(bytesWritten(qint64)),
this,SLOT(UpdateProgress(qint64)));
void client::sendDatagram()
{
qDebug()<<"sending ......";
TotalByte=0;
havewritedByte=0;
leftByte=0;
outblock=0;
loadSize=128; //每次发送数据的大小 i
magefile=new QFile("./linux.png");
if(!imagefile->open(QFile::ReadOnly))
{
qDebug() << "open file error!";
return;
}
TotalByte=imagefile->size();
//send datagram
QDataStream out(&outblock,QIODevice::WriteOnly);//datastream
out.setVersion(QDataStream:t_4_0);// set datastream setVersion
outblock= imagefile->read(loadSize);//一次性读取128B数据
udpSocket->writeDatagram(outblock, QHostAddress::Broadcast,
ui->ortlineEdit->text().toInt());}
void client::UpdateProgress(qint64 havesendbyte)
{
qDebug()<<"TotalByte is ......"<<TotalByte;
havewritedByte+=havesendbyte;
qDebug()<<"havewritedByte is ......"<<havewritedByte;
leftByte=TotalByte-havewritedByte;
qDebug()<<"leftByte is ......"<<leftByte;
ui->sendProgressbar->setMaximum(TotalByte);
ui->sendProgressbar->setValue(havewritedByte);
if(leftByte>0)
{
outblock= imagefile->read(qMin(leftByte,loadSize));
udpSocket->writeDatagram(outblock,
QHostAddress::Broadcast,
ui->ortlineEdit->text().toInt());
}
else//发送完
{
delete imagefile;
udpSocket->close();
outblock.resize(0);
}
}
接受端：
//有收到数据就更新UI
connect( udpSocket, SIGNAL( readyRead() ),
this, SLOT( processDatagrms_slot() ) );
connect( this, SIGNAL( haveDatagrams_signal( qint64, QByteArray ) ),
this, SLOT( updateServerProgress( qint64, QByteArray ) ) );
void server::processDatagrms_slot()
{
while ( udpSocket->hasPendingDatagrams() )
{
this->inblock.resize( this->udpSocket->pendingDatagramSize() );
//get 数据包大小
this->udpSocket->readDatagram( inblock.data(), inblock.size() );
emit haveDatagrams_signal( this->inblock.size(), inblock);
}
//接受over ，就显示图片
QPixmap pixmap;//pixel map
pixmap.loadFromData( countblock ); //load all image byteArray data
if ( !pixmap.isNull() ) //is image
{
qDebug()<<"ui->imagelabel_3->setPixmap( pixmap ) .....";
ui->imagelabel_3->setPixmap( pixmap ); //将图片加载到label
ui->imagelabel_3->show();
}
else
{
ui->imagelabel_3->setText("123...");
qDebug()<<"NO LOAD Image ..image is null...";
}
inblock.resize(0);
countblock.resize(0);
bytesReceived=0;
}
//更新进度条
void server::updateServerProgress( qint64 byteshaveReceived, QByteArray havereceiveDatagrams )
{
qDebug() << "updateServerProgress run ......";
countblock += havereceiveDatagrams;//累加数据包，用来显示图片
bytesReceived += byteshaveReceived;
qDebug() << "bytesReceived is ......" << bytesReceived;
...........
}
