/// <summary>
/// This method saves the user data both to memory, and subsequently to persistent storage.
/// </summary>
private async void SaveData( )
{
// Save the user data to memory.
StaticUserDataStore.UserData = _appUserData;
// Write the data to persistent storage.
var fileWriteStream = await _fileStreamRetriever.ObtainFileStreamAsync(StaticUserDataStore.UserFileName, true, FileAccess.ReadAndWrite);
var writeTask = _userDataStreamWriter.Write(fileWriteStream, _appUserData);
// Navigate back to previous page upon saving.
NavigationParameters navigationParameters = new NavigationParameters();
navigationParameters.Add("userData", _appUserData);
await _navigationService.GoBackAsync(navigationParameters);
}
public async void OnNavigatingTo(NavigationParameters parameters)
{
// Attempt to load the user data from the store.
var userDataFileExists = await _fileStreamRetriever.CanObtainStreamFromPathAsync(StaticUserDataStore.UserFileName);
if (userDataFileExists)
{
// Attempt to load the user data.
var stream = await _fileStreamRetriever.ObtainFileStreamAsync(StaticUserDataStore.UserFileName, false, FileAccess.Read);
var appUserData = _jsonObjectStreamReader.Read <AppUserData>(stream);
// Navigate to the homepage.
var navigationParameters = new NavigationParameters();
navigationParameters.Add("userData", appUserData);
await _navigationService.NavigateAsync("/GNav/MainPage");
}
else
{
// Load the enter user details page.
await _navigationService.NavigateAsync("/GNav/MainPage/EditUser");
}
}
private async Task <AppUserData> LoadAppUserDataFromFileAsync(string userFileName)
{
var fileReadStream = await _fileStreamRetriever.ObtainFileStreamAsync(userFileName, false, FileAccess.Read);
return(await _jsonObjectStreamReader.Read <AppUserData>(fileReadStream));
}