Apply Themes to WPF applications

NuGet command:

PM> Install-Package wpfthemes

As the WPF.Themes is built in Environment .Net 4.0, if we are building our application for .Net 4.0 above version, we can apply themes simply like below:

using WPF.Themes;     

namespace UseNuGetApplyThemes 

{     
     /// Interaction logic for MainWindow.xaml           public partial class MainWindow : Window     

      {         

          public MainWindow()         

         {             

             InitializeComponent();             

             this.ApplyTheme("WhistlerBlue");         

         }     

     } 

} 

The Themes names can be:

• ExpressionDark
• ExpressionLight
• Rainier
• RainierPurple
• RainierOrange
• RainierRadialBlue
• Shiny
• ShinyDarkGreen
• ShinyDarkTeal
• ShinyDarkPurple
• ShinyBlue
• ShinyRed
• Bureau
• BureauBlack
• BureauBlue
• Whistler
• WhistlerBlue
• DavesGlossyControls
• DavesGlossyControls
• UXMusing
• UXMusingRed
• UXMusingGreen
• UXMusingRough
• UXMusingRoughGreen
• UXMusingRoughRed
  
• UXMusingBubbly
• UXMusingBubblyBlue

Let's use ILSpy to analyze the WPF.Themes.dll assembly, we will see it use ThemeManager class extension method to apply themes, it is merge the theme to app resources dictionary, so if not .net 4.0 application, like .net 3.5, we can use its ThemeManager class, sometimes we don't want all the themes files included in the assemblies or use other themes not in the above list, we can use its method to apply themes too. Let's post it below:

using System;
using System.Reflection;
using System.Windows;
using System.Windows.Controls;
namespace WPF.Themes
{
 public static class ThemeManager
 {
  public static readonly DependencyProperty ThemeProperty = DependencyProperty.RegisterAttached("Theme", typeof(string), typeof(ThemeManager), new FrameworkPropertyMetadata(string.Empty, new PropertyChangedCallback(ThemeManager.OnThemeChanged)));
  public static ResourceDictionary GetThemeResourceDictionary(string theme)
  {
   ResourceDictionary result;
   if (theme != null)
   {
    Assembly assembly = Assembly.LoadFrom("WPF.Themes.dll");
    string uriString = string.Format("/WPF.Themes;component/{0}/Theme.xaml", theme);
    result = (Application.LoadComponent(new Uri(uriString, UriKind.Relative)) as ResourceDictionary);
   }
   else
   {
    result = null;
   }
   return result;
  }
  public static string[] GetThemes()
  {
   return new string[]
   {
    "ExpressionDark", 
    "ExpressionLight", 
    "ShinyBlue", 
    "ShinyRed", 
    "DavesGlossyControls", 
    "WhistlerBlue", 
    "BureauBlack", 
    "BureauBlue", 
    "BubbleCreme", 
    "TwilightBlue", 
    "UXMusingsRed", 
    "UXMusingsGreen", 
    "UXMusingsBubblyBlue"
   };
  }
  public static void ApplyTheme(this Application app, string theme)
  {
   ResourceDictionary themeResourceDictionary = ThemeManager.GetThemeResourceDictionary(theme);
   if (themeResourceDictionary != null)
   {
    app.Resources.MergedDictionaries.Clear();
    app.Resources.MergedDictionaries.Add(themeResourceDictionary);
   }
  }
  public static void ApplyTheme(this ContentControl control, string theme)
  {
   ResourceDictionary themeResourceDictionary = ThemeManager.GetThemeResourceDictionary(theme);
   if (themeResourceDictionary != null)
   {
    control.Resources.MergedDictionaries.Clear();
    control.Resources.MergedDictionaries.Add(themeResourceDictionary);
   }
  }
  public static string GetTheme(DependencyObject d)
  {
   return (string)d.GetValue(ThemeManager.ThemeProperty);
  }
  public static void SetTheme(DependencyObject d, string value)
  {
   d.SetValue(ThemeManager.ThemeProperty, value);
  }
  private static void OnThemeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
  {
   string text = e.NewValue as string;
   if (!(text == string.Empty))
   {
    ContentControl contentControl = d as ContentControl;
    if (contentControl != null)
    {
     contentControl.ApplyTheme(text);
    }
   }
  }
 }
}