Trying to dump an "unsigned char" array to file!

[fernando306]

Hi there! How are you?

My problem is fairly simple for those used to CLI programming!

I basically have an "unsigned char" type array that I need to dump to a file and later be able to read it back, like an EEPROM memory. It's quite simple, but I am having difficulty to find the information on how that could be accomplished. I tried to use StreamWriter but I did not succeed. The code bellow compiles, but all I get is the "System.Byte[]" message on the created file...

array<unsigned char>^ array3 = gcnew array<unsigned char>(8);

array3[0]=10;
array3[1]=77;
array3[2]=24;
array3[3]=56;
array3[4]=17;
array3[5]=76;
array3[6]=72;
array3[7]=05;

String^ fileName = "textfile.txt";
StreamWriter^ sw = gcnew StreamWriter(fileName);
sw->Write(array3);
sw->Close();

Edit: And ah! After I succeed writing it, how to read it back??

Any help will be greatly appreciated!

Thanks!

[Eri523]

Hi there! How are you?

Fine. (For the unlikely case this question is actually meant for me... )

Looks like what you actually want is a FileStream rather than a StreamWriter. Like this:

String ^fileName = "textfile.txt";
FleStream ^fs = gcnew FileStream(fileName, FileMode::Create);
fs->Write(array3, 0, array3->Length);
fs->Close();

Already the first line of the MSDN StreamWriter doc page could have been a useful indicator that this isn't what you actually want, BTW:

Implements a TextWriter for writing characters to a stream in a particular encoding.

[...] And ah! After I succeed writing it, how to read it back??

Reading it back is much like writing it; you'd even use the same framework class. Just study the MSDN docs.

However, if what you actually want is text file handling, a StreamWriter may very well be what you're looking for. It just doesn't have a Write(array<unsigned char> ^) overload (the C++ unsigned char is equivalent to the .NET System::Byte). Appropriate objects to pass to TextWriter::Write() are, among others, array<System::Char> ^ (note the capital C, where the equivalent native item type is wchar_t rather than unsigned char) or simply System::String ^.

BTW, code tags?

[fernando306]

Hi Eri523! Thank you so much for your help. I'll definitively study the FileStream class and implement it. No, I'm not handling text files, so you surely saved me from a lot of headaches

Oh yeah! Code tags!

I'll get back here ASAP. Happy Xmas BTW!

[fernando306]

Hey Eri523!

I used FileStream and it worked 100% fine. I also used OpenFileDialog and SaveFileDialog to browse directories and provide the file path. It was a piece of cake!

Thanks a lot, your suggestion was great!

Best wishes,

Fernando