在WPF中创建UI设置的正确方法是什么？

Question

I'm working now on a base Style in XAML which includes a Template for my standard HandledWindow type. The style includes several local resources like colours, fonts and other variables to reuse later in my style.

I was thinking of UI settings for the user, so he can change things like colours and sizes as he wishes. But then I've discovered that changing the local resource won't change the style itself but only for the current HandledWindow instance, So it's not suitable way for UI settings since there might be more then running window in the application.

Then I realised I have to bind variables relatively to the template of my HandledWindow class, which will include all changeable settings as public & static properties. But then I encountered an issue with static property binding since I cannot raise the PropertyChanged event which works only for an instance. And the window won't update it's style by itself.

In addition I am trying to make the style react and update immediately on the fly without restarts.

Answer 1

WPF is "resource-centric". You define all your UI styles, brushes and templates in your resources and at runtime it is very easy to enable application-wide theme change that would encompass all the properties you mention. Here is how I do it in my MainViewModel after it receives a message from my Settings Window via its SettingsViewModel:

private void ApplyTheme()
{          
    Application.Current.Resources.MergedDictionaries.Clear();

    var rd = new ResourceDictionary { { "Locator", locator } };
    Application.Current.Resources.MergedDictionaries.Add(rd);

    switch (theme)
    {
        case "Blue":
            Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("/Telerik.Windows.Themes.Office_Blue;component/Themes/System.Windows.xaml", UriKind.RelativeOrAbsolute) });
            Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("/Telerik.Windows.Themes.Office_Blue;component/Themes/Telerik.Windows.Controls.GridView.xaml", UriKind.RelativeOrAbsolute) });
            Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("/Telerik.Windows.Themes.Office_Blue;component/Themes/Telerik.Windows.Controls.Input.xaml", UriKind.RelativeOrAbsolute) });
            Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("/Telerik.Windows.Themes.Office_Blue;component/Themes/Telerik.Windows.Controls.Navigation.xaml", UriKind.RelativeOrAbsolute) });
            Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("/Telerik.Windows.Themes.Office_Blue;component/Themes/Telerik.Windows.Controls.xaml", UriKind.RelativeOrAbsolute) });
            break;
        case "Summer":
            Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("/Telerik.Windows.Themes.Summer;component/Themes/System.Windows.xaml", UriKind.RelativeOrAbsolute) });
            Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("/Telerik.Windows.Themes.Summer;component/Themes/Telerik.Windows.Controls.GridView.xaml", UriKind.RelativeOrAbsolute) });
            Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("/Telerik.Windows.Themes.Summer;component/Themes/Telerik.Windows.Controls.Input.xaml", UriKind.RelativeOrAbsolute) });
            Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("/Telerik.Windows.Themes.Summer;component/Themes/Telerik.Windows.Controls.Navigation.xaml", UriKind.RelativeOrAbsolute) });
            Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("/Telerik.Windows.Themes.Summer;component/Themes/Telerik.Windows.Controls.xaml", UriKind.RelativeOrAbsolute) });
            break;
        }
        Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("Resources/Brushes.xaml", UriKind.RelativeOrAbsolute) });
        Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("Resources/ControlTemplates.xaml", UriKind.RelativeOrAbsolute) });
        Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("Resources/DataTemplates.xaml", UriKind.RelativeOrAbsolute) });
        Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = new Uri("Resources/Styles.xaml", UriKind.RelativeOrAbsolute) });
    }

Obviously I am using Telerik controls so I load their dictionaries but at the bottom of the method you'll notice I load my own resources like Brushes, Styles etc. as well.

In conclusion, application-wide theme changes could not be easier with WPF.