This is a scenario which is easily resolved with dependency injection.
Have a interface with the desired methods on your shared or PCL code, like:
public interface IUserPreferences
{
void SetString(string key, string value);
string GetString(string key);
}
Have a property on your App class of that interface:
public class App
{
public static IUserPreferences UserPreferences { get; private set; }
public static void Init(IUserPreferences userPreferencesImpl)
{
App.UserPreferences = userPreferencesImpl;
}
(...)
}
Create platform-specific implementations on your target projects:
IOS
public class iOSUserPreferences : IUserPreferences
{
public void SetString(string key, string value)
{
NSUserDefaults.StandardUserDefaults.SetString(key, value);
}
public string GetString(string key)
{
(...)
}
}
Android
public class AndroidUserPreferences : IUserPreferences
{
public void SetString(string key, string value)
{
var prefs = Application.Context.GetSharedPreferences("MySharedPrefs", FileCreationMode.Private);
var prefsEditor = prefs.Edit();
prefEditor.PutString(key, value);
prefEditor.Commit();
}
public string GetString(string key)
{
(...)
}
}
Then on each platform-specific project create an implementation of IUserPreferences and set it using either App.Init(new iOSUserPrefernces()) and App.Init(new AndroidUserPrefernces()) methods.
Finally, you could change your code to:
public class MyPage : ContentPage
{
public MyPage()
{
//do work to initialize MyPage
}
public void LogIn(object sender, EventArgs eventArgs)
{
bool isAuthenticated = false;
string accessToken = string.Empty;
//do work to use authentication API to validate users
if(isAuthenticated)
{
App.UserPreferences.SetString("AccessToken", accessToken);
}
}
}
Hope This Will be Helpful
