Qt ：图片与QByteArray互转

1 将图片转为QByteArray传输

QBuffer buffer;

        buffer.open(QIODevice::ReadWrite);

//pixmap不能为空，必须先将图片加载到pixmap中

        pixmap.save(&buffer,"jpg");

        QByteArray pixArray;

        pixArray.append(buffer.data());

2 将QByteArray转为图片显示

       QByteArray array;

       while(client->waitForReadyRead(100)){

           array.append((QByteArray)client->readAll());

       }

       QBuffer buffer(&array);

       buffer.open(QIODevice::ReadOnly);

       QImageReader reader(&buffer,"JPG");

       QImage img = reader.read();

       if(!img.isNull()){

           QPixmap pix = QPixmap::fromImage(img);

           ui->showImageLabel->setPixmap(pix.scaled(ui->showImageLabel->size(),Qt::KeepAspectRatio,Qt::SmoothTransformation));

}