copy unsigned char array into QByteArray ..... problems

[o6a6r9v1p]

Thanks to all,
in the test code, i am initializing the array with integers.
then i tried to assign or copy into QByteArray.
while copy/paste, missed the lines.

int i;
for(i=0;i<20;i++){
    wbuf[i]=i;
}
 m_writeData =QByteArray::fromRawData(wbuf, sizeof(wbuf));

how to change the above line of code.

Thanks.

[o6a6r9v1p]

@J.Hilk hi,
passed buf[] as you told, as a parameter to QSerialPort(), but it gives same error.
The code is:

for(i=0;i<20;i++){
    wbuf[i]=i;
}

const qint64 bytesWritten = serPort->write(wbuf));

the error is:

invalid conversion from  "unsigned char*" to "const char*"

can you point to examples or doc pages, if possible.

Thanks.

[jsulm]

@o6a6r9v1p Please read what @raven-worx wrote (hint: casting)

[o6a6r9v1p]

@jsulm
hi,
can we do it the way it is done C?
or is it different in C++?

I am not good in C++.

Thanks.

[jsulm]

@o6a6r9v1p

const qint64 bytesWritten = serPort->write(reinterpret_cast<char*>(wbuf)));

[J.Hilk]

@o6a6r9v1p
take a look here

http://www.cplusplus.com/doc/tutorial/typecasting/

you can use c-style casting, but you're encuraged to use the cpp variants

[o6a6r9v1p]

@jsulm
hi,
Thanks for the word. this line was used, think i am wrong some where.

const qint64 bytesWritten = serPort->write(const QByteArray ((unsigned char*) wbuf));

where did i miss?

Thanks,

[jsulm]

@o6a6r9v1p Why do you create a byte array? @J-Hilk already said here that this is not needed.
What is wrong in your code: remove the const before QByteArray. You should learn more about C++.

[o6a6r9v1p]

@jsulm
hi,
sending data bytes in certain order.
we use a structure of bytes.

[jsulm]

@o6a6r9v1p Again: there is NO need for QByteArray.
This line should work as well, did you try?

const qint64 bytesWritten = serPort->write(reinterpret_cast<char*>(wbuf)));

[o6a6r9v1p]

@jsulm
removed const as told.
still i am getting:

invaild conversion from unsigned char* to const char* error.

i know c programming, but not good in c++,

thanks,

[jsulm]

@o6a6r9v1p You should read more carefully - I already showed you what you need to do.

1. Why do you want to use QByteArray? It is not needed. QByteArray does not care about any order - it is the order you give it.
2. You need to cast unsigned char* to char*. See my previous posts to see how, I don't want to write it again and again.

[o6a6r9v1p]

@jsulm
hi,
i under stood that line in wrongly. in the place of <char *>, i have used const QByteArray.
Now i got the point after going trough the type casting page, adviced by you.

Now it is working.
Thanks to all of you.