You can simplify the operation of saving, retrieving and selecting the Application theme and backdrop. All operations are performed automatically.

Backdrops

Name
None
Mica
MicaAlt
Acrylic
AcrylicThin
Transparent

Events

Name
ThemeChanged
BackdropChanged

Properties

Name
IsDark
ElementTheme
ActualTheme
BackdropType

Methods

Name
Window
SetElementThemeAsync
SetElementThemeWithoutSaveAsync
SetBackdropTypeAsync
SetBackdropTypeWithoutSaveAsync
GetAcrylicSystemBackdrop
GetMicaSystemBackdrop
GetSystemBackdrop
OnThemeComboBoxSelectionChanged
SetThemeComboBoxDefaultItem
OnBackdropComboBoxSelectionChanged
SetBackdropComboBoxDefaultItem
OnThemeRadioButtonChecked
SetThemeRadioButtonDefaultItem
OnBackdropRadioButtonChecked
SetBackdropRadioButtonDefaultItem
Dispose
ConfigureAutoSave
ConfigureElementTheme
ConfigureBackdrop
Initialize

Simple Usage

var themeService = new ThemeService();
themeService.Initialize(window);

Configs

there are some configure methods:

ConfigureBackdrop

If you use the ConfigureBackdrop, the themeService will automatically save and restore the SystemBackdrop (if ConfigureAutoSave is enabled (by default it is enabled))

themeService.ConfigureBackdrop(BackdropType.Mica).Initialize(window);

ConfigureElementTheme

If you use the ConfigureElementTheme, the themeService will automatically save and restore the ElementTheme (if ConfigureAutoSave is enabled (by default it is enabled))

themeService.ConfigureElementTheme(ElementTheme.Default).Initialize(window);

ConfigureAutoSave

themeService.ConfigureAutoSave(true, filePath).Initialize(window);

Changing ElementTheme in Runtime

you can change ElementTheme in Runtime like this:

await themeService.SetElementThemeAsync(ElementTheme.Dark);

Changing SystemBackdrop Type in Runtime

you can change SystemBackdrop Type in Runtime like this:

await themeService.SetBackdropTypeAsync(BackdropType.Mica);

MVVM Pattern

first register a IThemeService service:

services.AddSingleton<IThemeService, ThemeService>();

then in your App.xaml.cs

var themeService = GetService<IThemeService>() as ThemeService;
themeService.Initialize(Window);

Multi-Window

if you have multiple window, you need to use WindowHelper.TrackWindow method, before Activate your window.

Window myWindow = new Window();
WindowHelper.TrackWindow(myWindow);
myWindow.Activate();

TintColor (Mica and Acrylic)

There are no built-in methods for working with TintColor. However, you can access the current backdrop by calling GetAcrylicSystemBackdrop or GetMicaSystemBackdrop, and then modify the TintColor property manually.

Auto Change Theme/Backdrop and Auto Load Default Item

if you want to set defualt item for combobox or radiobuttons, and auto switch between themes or backdrops just add following line in your xaml

ComboBox

<ComboBox dev:ThemeServiceAttach.ThemeService="{x:Bind local:App.Current.GetThemeService}">
    <ComboBoxItem Content="Light" Tag="Light" />
    <ComboBoxItem Content="Dark" Tag="Dark" />
    <ComboBoxItem Content="Default" Tag="Default" />
</ComboBox>

<ComboBox dev:ThemeServiceAttach.ThemeService="{x:Bind local:App.Current.GetThemeService}">
    <ComboBoxItem Tag="None" Content="None"/>
    <ComboBoxItem Tag="Mica" Content="Mica"/>
    <ComboBoxItem Tag="MicaAlt" Content="Mica Alt"/>
    <ComboBoxItem Tag="Acrylic" Content="Acrylic"/>
    <ComboBoxItem Tag="AcrylicThin" Content="Acrylic Thin"/>
    <ComboBoxItem Tag="Transparent" Content="Transparent"/>
</ComboBox>

RadioButtons

<StackPanel dev:ThemeServiceAttach.ThemeService="{x:Bind local:App.Current.GetThemeService}">
    <RadioButton Tag="Light" Content="Light"/>
    <RadioButton Tag="Dark"  Content="Dark" />
    <RadioButton Tag="Default" Content="Use system setting" />
</StackPanel>

 <StackPanel dev:ThemeServiceAttach.ThemeService="{x:Bind local:App.Current.GetThemeService}">
    <RadioButton Tag="None" Content="None"/>
    <RadioButton Tag="Mica" Content="Mica"/>
    <RadioButton Tag="MicaAlt" Content="Mica Alt" />
    <RadioButton Content="Acrylic" Tag="Acrylic" />
    <RadioButton Content="Acrylic Thin" Tag="AcrylicThin" />
    <RadioButton Content="Transparent" Tag="Transparent" />
</StackPanel>

Auto Change Theme/Backdrop and Auto Load Default Item (Old Methods)

ComboBox

if you want to handle everything by yourself, first of all remove dev:ThemeServiceAttach.ThemeService="{x:Bind local:App.Current.GetThemeService}" and then add your events:

for changing and saving application theme / backdrop:

private void cmbTheme_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    themeService.OnThemeComboBoxSelectionChanged(sender);
    themeService.OnBackdropComboBoxSelectionChanged(sender);
}

for selecting currect combobox item when page is loading, you can call SetThemeComboBoxDefaultItem or SetBackdropComboBoxDefaultItem method in Page Loaded event:

themeService.SetThemeComboBoxDefaultItem(cmb1);
themeService.SetBackdropComboBoxDefaultItem(cmb2);

RadioButtons

if you want to handle everything by yourself, first of all remove dev:ThemeServiceAttach.ThemeService="{x:Bind local:App.Current.GetThemeService}" and then add your events:

for changing and saving application theme / backdrop:

private void OnThemeRadioButtonChecked(object sender, RoutedEventArgs e)
{
    themeService.OnThemeRadioButtonChecked(sender);
    themeService.OnBackdropRadioButtonChecked(sender);
}

for selecting currect radiobutton item when page is loading, you can call SetThemeRadioButtonDefaultItem or SetBackdropRadioButtonDefaultItem method in Page Loaded event:

themeService.SetThemeRadioButtonDefaultItem(ThemePanel1);
themeService.SetBackdropRadioButtonDefaultItem(ThemePanel2);

Demo

you can run demo and see this feature.