Cant switch themes after updating to 5.0 about materialdesigninxamltoolkit

[jbooth88]

I don't know if it's the "right way", but try this

var newTheme = _darkTheme ? BaseTheme.Dark : BaseTheme.Light;
var colorKey = nameof(MaterialDesignColor.DeepPurple);
var swatchProvider = new SwatchesProvider();
var swatch = swatchProvider.Swatches.FirstOrDefault(x => string.Equals(x.Name, colorKey, StringComparison.OrdinalIgnoreCase));
if (swatch != null)
{
    var paletteHelper = new PaletteHelper();
    var theme = paletteHelper.GetTheme();
    theme.SetBaseTheme(newTheme);
    theme.SetPrimaryColor(swatch.ExemplarHue.Color);
    theme.SetSecondaryColor(swatch.SecondaryExemplarHue?.Color ?? swatch.ExemplarHue.Color); //nullable SecondaryExemplarHue? I don't know what to do here.
    paletteHelper.SetTheme(theme);
}

[Keboo]

It is actually slightly easier to do in the 5.0 release.

You still need to get an instance of the Theme. This will typically be done with PaletteHelper.GetTheme() or the GetTheme() extension method on ResourceDictionary. Once you have that theme instance you can switch between Light/Dark themes simply by calling SetDarkTheme()/SetLightTheme() directly on it, which will update the internal brushes with the corresponding values. Finally, to apply the theme, you will need to call PaletteHelper.SetTheme(Theme) or more generically the SetTheme() extension method on ResourceDictionary.

[Jonesie]

Thanks people :)

This works:

var ph = new PaletteHelper();
var theme = ph.GetTheme();
if (theme != null)
{
  if (_darkTheme)
    theme.SetDarkTheme();
  else
    theme.SetLightTheme();
  ph.SetTheme(theme);
}