// show a dialog to open a file
FilePickerCross myFile = await FilePickerCross.importFromStorage(
  type: FileTypeCross.any,       // Available: `any`, `audio`, `image`, `video`, `custom`. Note: not available using FDE
  fileExtension: 'txt, md'     // Only if FileTypeCross.custom . May be any file extension like `dot`, `ppt,pptx,odp`
);

// save our file to the fictional directory. It is not necessary that it already exists.
myFile.saveToPath('/my/awesome/folder/' + myFile.fileName);

// save our file to the internal storage or share to other apps
myFile.exportToStorage();

// for sharing to other apps you can also specify optional `text` and `subject`
myFile.exportToStorage(
  subject: "Awesome file",
  text: "Here is the file you've been waiting for",
);

// on iPad you may also need to specify the `sharePositionOrigin` for native share UI
GlobalKey widgetKey = GlobalKey();
...
RenderBox renderBox = widgetKey.currentContext.findRenderObject();
Offset position = renderBox.localToGlobal(Offset.zero);
filePickerCross.exportToStorage(
    position.dx, position.dy, renderBox.size.width, renderBox.size.height);

List<FilePickerCross> myMultipleFiles = await FilePickerCross.importMultipleFromStorage();
print(myMultipleFiles);

// list all previously opened files
List<String> paths = await FilePickerCross.listInternalFiles();
print(paths);

// open an existing file
FilePickerCross anotherFile = FilePickerCross.fromInternalPath(paths[0]);

// delete our perfect file
FilePickerCross.delete(paths[0]);

// get the file storage size
print(await FilePickerCross.quota());

// you can access the following properties on a FilePickerCross instance:

myFile.toString();

myFile.toUint8List();

myFile.toBase64();

myFile.toMultipartFile(filename: 'myFile.txt');

myFile.length;

myFile.path;

myFile.fileName;

myFile.fileExtension;

myFile.directory;

await FilePickerCross.importFromStorage().then(() {
  // ...
}).onError((error, _) {
  String _exceptionData = error.reason();
  print('----------------------');
  print('REASON: ${_exceptionData}');
  if (_exceptionData == 'read_external_storage_denied') {
    print('Permission was denied');
  } else if (_exceptionData == 'selection_canceled') {
    print('User canceled operation');
  } 
  print('----------------------');
});

// for the first file, you show an export as dialog
FilePickerCross myFile = ...

String pathForExports = await myFile.exportToStorage(); // <- will return the file's path on desktops

// you parse the file's directory and use it for later automated exports.
pathForExports = pathForExports.substring(0,pathForExports.lastIndexOf(r'/'));
print(pathForExports);

// now save the path for later use using shared preferences etc.
...

// next time, check whether you are overwriting an existing file or simply write the file
print(await File(pathForExports+'/myNextFile.csv').exists());
File myCsvFile = await File(pathForExports+'/myNextFile.csv').writeAsString('comma,separated,values'); // <- This only works on desktops. All other devices prevent this.