<![CDATA[Reading a binary file]]>hi to everyone
i am trying to read a binary file and save it to my db as a blob data(qsqlite)
i use this code
@ QFIle myfile("1.zip");
QByteArray x;
if(!myfile.open())
return;
while(!myfile.atEnd())
x = myfile.readall();
QFIle myfile1("1.png");
QByteArray x1;
if(!myfile1.open())
return;
while(!myfile1.atEnd())
x1 = myfile1.readall();
@
i think it only read the a few first charachters of my file
how can i solve this?

]]>https://forum.qt.io/topic/10335/reading-a-binary-fileRSS for NodeMon, 20 Apr 2026 06:17:51 GMTWed, 12 Oct 2011 05:16:00 GMT60<![CDATA[Reply to Reading a binary file on Thu, 13 Oct 2011 13:36:10 GMT]]>You're speaking of charactares, which makes me guess that you're on the wrong concept.

You must not print arbitrary binary data with printf() or qDebug()! As cincirin already mentioned, this stops at the first null-byte (0x00) regardless how big your data is.

You must check the byte array's size with x.size().

]]>https://forum.qt.io/post/113153https://forum.qt.io/post/113153Thu, 13 Oct 2011 13:36:10 GMT<![CDATA[Reply to Reading a binary file on Thu, 13 Oct 2011 13:30:33 GMT]]>What is the value of @x.size()@ ?

]]>https://forum.qt.io/post/113154https://forum.qt.io/post/113154Thu, 13 Oct 2011 13:30:33 GMT<![CDATA[Reply to Reading a binary file on Thu, 13 Oct 2011 13:26:03 GMT]]>yes i am sure the data is incomplete
because the file is abour 200 kb but the x variable has only a few charachter(4 or 5 charachter)

]]>https://forum.qt.io/post/113152https://forum.qt.io/post/113152Thu, 13 Oct 2011 13:26:03 GMT<![CDATA[Reply to Reading a binary file on Wed, 12 Oct 2011 09:25:24 GMT]]>readAll is guaranteed to read all available data, so the while loop is completely unnecessary.

And so you think the data is incomplete? Did you proof yourself it actually is incomplete?

]]>https://forum.qt.io/post/113003https://forum.qt.io/post/113003Wed, 12 Oct 2011 09:25:24 GMT<![CDATA[Reply to Reading a binary file on Wed, 12 Oct 2011 08:48:25 GMT]]>Additionally, if readall does not return the whole file, you overwrite the previous data.

@
while(!myfile.atEnd())
x += myfile.readall();
@

or remove the while loop.

]]>https://forum.qt.io/post/112999https://forum.qt.io/post/112999Wed, 12 Oct 2011 08:48:25 GMT<![CDATA[Reply to Reading a binary file on Wed, 12 Oct 2011 07:00:48 GMT]]>bq. QByteArray can be used to store both raw bytes (including '\0's) and traditional 8-bit '\0'-terminated strings
Behind the scenes, it always ensures that the data is followed by a '\0' terminator

Perhaps this is the reason why you see only part of the array.

]]>https://forum.qt.io/post/112964https://forum.qt.io/post/112964Wed, 12 Oct 2011 07:00:48 GMT<![CDATA[Reply to Reading a binary file on Wed, 12 Oct 2011 06:06:31 GMT]]>I don't understand what the problem is. How can you say that only a few data is read from the file?

]]>https://forum.qt.io/post/112959https://forum.qt.io/post/112959Wed, 12 Oct 2011 06:06:31 GMT