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));

}