Android Preferences กับ Shared Preferences มีวิธีใช้ยังไงครับ

public class UserHelper {
	Context context;
	SharedPreferences sharedPerfs;
	Editor editor;
	
	// Prefs Keys
	static String perfsName = "UserHelper";
	static int perfsMode = 0;
	
	public UserHelper(Context context) {
		this.context = context;
		this.sharedPerfs = this.context.getSharedPreferences(perfsName, perfsMode);
		this.editor = sharedPerfs.edit();
	}
	
	public void createSession(String key) {
		editor.putBoolean("isLogin", true);
                editor.putString("userID", key);
                editor.commit();
	}
	
	public void deleteSession() {
		editor.clear();
		editor.commit();
	}
	
	public boolean isLogin() {
		return sharedPerfs.getBoolean("isLogin", false);
	}
	
	public String getUserID() {
		return sharedPerfs.getString("userID", null);
	}
}

UserHelper usrHelper = new UserHelper(this);

// Create Session
usrHelper.createSession(ID);

// Delete Session
usrHelper.deleteSession();

// Check Login
if (usrHelper.isLogin()) {

} else {

}

// Get UserID
usrHelper.getUserID()

SharedPreferences settings = getSharedPreferences("UserInfo", 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("sUsername",txtUsername.getText().toString());
editor.putString("sPassword",txtPassword.getText().toString());
editor.commit();

SharedPreferences settings = getSharedPreferences("UserInfo", 0);
string strUsername = settings.getString("sUsername", "").toString();
string strPassword = settings.getString("sPassword", "").toString();