Windows Phone 8 and read/write file

Question

My application have a small piece of code which read/write a file in C++/CX (Windows Phone 8 Interop DirectX) like this:

bool WriteState(char *fileName) {
    FILE *fp = fopen(fileName);
    if (fp) {
        // Do save
        ...
        fclose(fp);
        return true;
    }

    return false;
}

and ReadState has the same code. and invoking (call from C#):

ObjectClass game = new ObjectClass();
game.WriteState("game1.state");

It's no problem when I run on my device, debug with no error. But after I published to Windows Phone Store and install to my device, the Read/Write code doesn't work. Why this happen?

Answer 1

http://msdn.microsoft.com/en-us/library/windows/apps/jj681698(v=vs.105).aspx

There is this way, that should work for you..

Answer 2

Make sure you aren't saving the file in its install location. Your app won't have access to its install location in production. You'll need to save in isolated storage.