ui->setupUi(this);
//ui->pic1Label->setPixmap(QPixmap(":/pic.jpg"));
QImage image(":/pic.jpg");
ui->pic1Label->setPixmap(QPixmap::fromImage(image));
QByteArray ba;
QBuffer buffer(&ba);
buffer.open(QIODevice::WriteOnly);
if(image.save(&buffer, "JPG"))
qDebug()<< buffer.size();
QImage pic;
pic.loadFromData(buffer.data(),"JPG");
ui->pic2Label->setPixmap(QPixmap::fromImage(pic));
测试可以