我正在尝试通过QDataStream从客户端向服务器发送图像( OpenCV Mat )。 第一项是int，即缓冲区的大小。 它可以处理10到15张图片，然后服务器读取第一个int随机数(通常〜2 ^ 30)，这会导致应用崩溃。 这是客户端，处于一个循环中(图像来自摄像头，周期为500ms)：

//1) encode to jpg

cv::vector buf;

cv::imencode(".jpg", *mat, buf);

//2) write to buffer

QByteArray buffer;

QDataStream out(&buffer, QIODevice::WriteOnly);

out << int(0); // save place for an int which represents the buffer size

for(cv::vector::iterator it = buf.begin(); it != buf.end(); ++it)

{

out << *it; //write each byte

}

out.device()->seek(0); //write the buffer size

out << buffer.size();

qDebug() << "Sent " << buffer.size() << "bytes";

qint64 bytesSent = socket->write(buffer);

if(bytesSent < buffer.size())

{

if(bytesSent != -1)

{

qDebug() << "Transmit Error! Sent " << bytesSent << " out of " << buffer.size();

}

else

{

qDebug() << socket->errorString();

}

}

服务器端：

QDataStream in(socket);

int msgSize = -1;

//first read the size as an int

if(socket->bytesAvailable())

{

in >> msgSize;

}

qDebug() << "Read image size: " << msgSize << "bytes";

//wait until all bytes all available

while(socket->bytesAvailable() < ( qint64 ) ( ( qint64 )msgSize - sizeof(int) ) )

{

if(!socket->waitForReadyRead())

{

qDebug() << "Disconnected: " << socket->errorString();

socket->disconnectFromHost();

break;

}

}

qDebug() << "Bytes recieved: " << msgSize;

QByteArray ba;

quint8 byte;

for(int i = 0; i < msgSize - 1; ++i)

{

in >> byte;

ba.append(byte);

}

cv::Mat imgbuf = cv::Mat(FRAME_WIDTH, FRAME_HEIGHT, CV_8UC3, ba.data());

cv::Mat matImg = cv::imdecode(imgbuf, CV_LOAD_IMAGE_COLOR);

两个套接字都是QTcpSocket 。

输出示例：

The server side:

Read image size: 67551 bytes

Bytes recieved: 67551

Read image size: 56924 bytes

Bytes recieved: 56924

Read image size: 70027 bytes

Bytes recieved: 70027

Read image size: -2046830337 bytes

Bytes recieved: -2046830337

Read image size: -536866742 bytes

Bytes recieved: -536866742

Read image size: 1179207168 bytes

At this point it tries to read 1179207168 bytes.

The client side:

Sent 67551 bytes

Sent 56924 bytes

Sent 70027 bytes

Sent 70277 bytes

Sent 85633 bytes

Sent 65155 bytes

etc ...

只有前三个成功。