How to change theme whenever select value from listpicker in wp8 c#

Question

In my windows phone 8 application, I have theme setting's page like below:

In the listpicker control I have two values Dark and Light . And when I select Dark from listpicker control I want to change the theme of the application:

And In the themelistPicker1_SelectionChanged method, I am doing like below:

private void themelistPicker1_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            ListPickerItem lpi = (sender as ListPicker).SelectedItem as ListPickerItem;
            themename = lpi.Content.ToString();
            if (themename == "Dark")
            {
              App.dark();
            }
            else 
            {
                App.light();
            }
        }

And in the App.xaml.cs page I have define Dark and Light method defined like below:

using System;
using System.Diagnostics;
using System.Resources;
using System.Windows;
using System.Windows.Markup;
using System.Windows.Navigation;
using Microsoft.Phone.Controls;
using Microsoft.Phone.Shell;
using GetContacts.Resources;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Windows.Media;

namespace GetContacts
{
    public partial class App : Application
    {
        /// <summary>
        /// Provides easy access to the root frame of the Phone Application.
        /// </summary>
        /// <returns>The root frame of the Phone Application.</returns>
        /// <summary>
        /// Constructor for the Application object.
        /// </summary>
        public App()
        {
            // Global handler for uncaught exceptions.
            UnhandledException += Application_UnhandledException;

            // Standard XAML initialization
            InitializeComponent();

            // Phone-specific initialization
            InitializePhoneApplication();
            // Language display initialization
            InitializeLanguage();

            // Show graphics profiling information while debugging.
            if (Debugger.IsAttached)
            {
                // Display the current frame rate counters.
                Application.Current.Host.Settings.EnableFrameRateCounter = true;

                // Show the areas of the app that are being redrawn in each frame.
                //Application.Current.Host.Settings.EnableRedrawRegions = true;

                // Enable non-production analysis visualization mode,
                // which shows areas of a page that are handed off to GPU with a colored overlay.
                //Application.Current.Host.Settings.EnableCacheVisualization = true;

                // Prevent the screen from turning off while under the debugger by disabling
                // the application's idle detection.
                // Caution:- Use this under debug mode only. Application that disables user idle detection will continue to run
                // and consume battery power when the user is not using the phone.
                PhoneApplicationService.Current.UserIdleDetectionMode = IdleDetectionMode.Disabled;
            }
        }
        public static void dark()
        {
            (App.Current.Resources["PhoneAccentBrush"] as SolidColorBrush).Color = Color.FromArgb(12, 12, 54, 145);
            (App.Current.Resources["PhoneForegroundBrush"] as SolidColorBrush).Color = Colors.White;
            (App.Current.Resources["PhoneBackgroundBrush"] as SolidColorBrush).Color = Colors.Gray;
        }
        public static void light()
        {
            (App.Current.Resources["PhoneAccentBrush"] as SolidColorBrush).Color = Color.FromArgb(12, 12, 54, 145);
            (App.Current.Resources["PhoneForegroundBrush"] as SolidColorBrush).Color = Colors.Black;
            (App.Current.Resources["PhoneBackgroundBrush"] as SolidColorBrush).Color = Colors.White;
        }

    }
}

But when I select Dark theme PhoneBackgroundBrush=Black instead of Gray and PhoneForegroundBrush=white and when I select Light theme PhoneBackgroundBrush=Black instead of White and PhoneForegroundBrush=Black .

Kindly suggest me what I should do, to change the application theme after selection of value from listpicker control,do you have any idea? waiting for reply.

Thanks

Answer 1

I have an idea. Use ThemeManager developed by Jeff Wilcox By using ThemeManager you can change theme of Application.

Install ThemeManager Library in Nuget Packages & change your code like this..

private void themelistPicker1_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            ListPickerItem lpi = (sender as ListPicker).SelectedItem as ListPickerItem;
            themename = lpi.Content.ToString();
            if (themename == "Dark")
            {
              ThemeManager.ToDarkTheme();
            }
            else 
            {
              ThemeManager.ToLightTheme();
            }
        }

Hope this Helps