I believe QtTcpSocket is used in a manner similar to the following:
QTcpSocket* socket = new QTcpSocket;
QString serverAddr = "192.168.1.100";
quint16 serverPort = 12345;
char* data = ...;
qint64 dataSize = ...;
qint64 bytesWritten = 0;
while (bytesWritten < dataSize)
qint64 written = socket->write(data + bytesWritten, dataSize - bytesWritten);
if (written == -1)
// error; decide if you want to break from the loop, or try again.
bytesWritten += written;
You can read more here about QTcpSocket
. This class is a sub-class of QAbstractSocket
, which in turn is a sub-class of QIODevice
The links are pertinent to Qt 4.7.1; if this is not the version of Qt you are using, then please accept my apologies.