c++ - Convert byte array to picture -

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hello try convert byte array image each time null image, me please ? 

qimage image("p.jpg"); qdebug()<<image;   qimage image2; qbytearray paquet2; qdatastream out2(&paquet2, qiodevice::writeonly);  out2 << image;  qdebug()<<image2.fromdata(paquet2,"jpg");

qdebug 1 result: qimage(qsize(500,500))
qdebug 2 result: qimage(qsize(0,0))

fromdata() static method.

try image2.loadfromdata(paquet2) or qimage::fromdata(paquet2) instead.

i noticed strange, code works expected:

  qimage img("...");   qbytearray data;   qbuffer buff(&data);   qdatastream out(&buff);   out << img;   qdebug() << qimage::fromdata(data);

but gives warning iodevice not being open.

if manually buff.open(), fromdata() produces null image again.

without explicitly opening, openmode() automatically set unbuffered | writeonly , works, if open() explicitly unbuffered | writeonly doesn't work. go figure...


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