WP8 differences between file manipulation APIs in fileapi.h and stdio.h?

Question

According to Supported Win32 APIs for Windows Phone 8, WP8 does support many file manipulation APIs in fileapi.h like CreateFile2, ReadFile, WriteFile, ...

But when I include <stdio.h> I can use fopen, fread, fwrite, ...

Using both those APIs, I can create and read/write to a text file.

CreateFile2("hello.txt", ...);
fopen("hello.txt", ...);

... means other parameters, which aren't important to this question.

The other thing is that I don't know where that text file resides. Installed location isn't the case, because it is read-only location. The other case is Local folder, but I don't specify any Local folder path.

So what are the differences between those APIs (in fileapi.h and stdio.h) and which location does they act on ?

P/S: I'm doing in the WP Runtime Component

Answer 1

The main difference is the API set these functions use.

<stdio.h> contains the file APIs of the standard C library, <fileapi.h> is the Win32 APIs. There are also C++ APIs (<iostream>) which you could use.

I've found that whatever API you use, you should explicitly set the file location to the Local folder.

Platform::String^ localfolder = Windows::Storage::ApplicationData::Current->LocalFolder->Path;
Platform::String^ myFileName = Platform::String::Concat(localfolder, "\\myfile.txt");

One thing to watch is that Platform::String^ uses wchar_t, not char internally so you need to be a bit careful in specifying the file name.

So, try and find an API that takes wchar_t* for the file name and use that to avoid having to do character set conversion.

E.g.: Use _wfsopen instead of fopen.