[SOLVED]QDataStream writing wrong values

alok9871

Hi,

I'm building a program with a working thread.

@
QFile file("file.dat");
file.open(QIODevice::WriteOnly);
QDataStream out(&file);
out.setByteOrder(QDataStream::LittleEndian);
//out << QString("the answer is"); // serialize a string
int x = 54;
out << (qint32)x;
out.device()->close();
@

I was expecting an output of 54. Itself it writing its char value, that is,6; same is tha case with other numbers.

Please let me know how to address this problem

Thanks

Regards
Alok

ChrisW67

There is no problem. QDataStream is outputting exactly what you asked it to. You have a 32-bit unsigned integer with the value 54 and you have asked for output in LittleEndian order. The integer is 4 bytes 0x00000036, and QDataStream outputs them in reverse order. You get 4 bytes in the file, the first is 54 decimal (0x36) followed by 3 zero bytes. Treated as text this is equivalent to the C string "6".

@ const int num = 54;

QFile out("out.txt");
if (out.open(QIODevice::WriteOnly) {
QTextStream s(&out);
s << num;
}

@
Also look at QString::number(), QByteArray::number() etc.