从c#更新主题资源?

您可以看看模板10是如何改变主题的,但在他们的情况下,他们提前在资源字典中定义了两个不同的主题。您可以在 repo on Github ,但以下是使用的一些代码:

(Window.Current.Content as FrameworkElement).RequestedTheme = value.ToElementTheme();
Views.Shell.SetRequestedTheme(value, UseBackgroundChecked);

从…起 here

public static void SetRequestedTheme(ApplicationTheme theme, bool UseBackgroundChecked)
    {

        WindowWrapper.Current().Dispatcher.Dispatch(() =>
        {
            (Window.Current.Content as FrameworkElement).RequestedTheme = theme.ToElementTheme();

            ParseStyleforThemes(theme);

            HamburgerMenu.NavButtonCheckedForeground = NavButtonCheckedForegroundBrush;

            HamburgerMenu.NavButtonCheckedBackground = (UseBackgroundChecked) ?
                NavButtonCheckedBackgroundBrush : NavButtonBackgroundBrush;

            HamburgerMenu.NavButtonCheckedIndicatorBrush = (UseBackgroundChecked) ?
                Colors.Transparent.ToSolidColorBrush() : NavButtonCheckedIndicatorBrush;

            HamburgerMenu.SecondarySeparator = SecondarySeparatorBrush;

            List<HamburgerButtonInfo> NavButtons = HamburgerMenu.PrimaryButtons.ToList();
            NavButtons.InsertRange(NavButtons.Count, HamburgerMenu.SecondaryButtons.ToList());

            List<HamburgerMenu.InfoElement> LoadedNavButtons = new List<HamburgerMenu.InfoElement>();

            foreach (var hbi in NavButtons)
            {
                StackPanel sp = hbi.Content as StackPanel;
                if (hbi.ButtonType == HamburgerButtonInfo.ButtonTypes.Literal) continue;
                ToggleButton tBtn = sp.Parent as ToggleButton;
                Button btn = sp.Parent as Button;

                if (tBtn != null)
                {
                    var button = new HamburgerMenu.InfoElement(tBtn);
                    LoadedNavButtons.Add(button);
                }
                else if (btn != null)
                {
                    var button = new HamburgerMenu.InfoElement(btn);
                    LoadedNavButtons.Add(button);
                    continue;
                }
                else
                {
                    continue;
                }

                Rectangle indicator = tBtn.FirstChild<Rectangle>();
                indicator.Visibility = ((!hbi.IsChecked ?? false)) ? Visibility.Collapsed : Visibility.Visible;

                if (!hbi.IsChecked ?? false) continue;

                ContentPresenter cp = tBtn.FirstAncestor<ContentPresenter>();
                cp.Background = NavButtonCheckedBackgroundBrush;
                cp.Foreground = NavButtonCheckedForegroundBrush;
            }

            LoadedNavButtons.ForEach(x => x.RefreshVisualState());

        });
    }

从…起 here

我有一个空白,用于分析图像,提取两种主要颜色,并替换我在App.xaml中覆盖的“SystemControlForegroundAccentBrush”和“SystemContrrolHighlightAccentBruch”。

首先,我不认为你的代码在应用程序中。xaml可以覆盖 ThemeResource ,你用了这个 Brush 在页面中如下所示:

<TextBlock Foreground="{ThemeResource SystemControlForegroundAccentBrush}" Text="Hello World!" FontSize="50" />

如果您在 SystemControlForegroundAccentBrush ,您可以在“generic.xaml”文件中找到该资源。

现在假设您的 ColorExtractor.cs 班级工作顺利 ColorExtractor.Analyse() 可以覆盖这两个画笔的颜色,并且页面中有许多控件使用这两个资源,刷新此处的页面可以解决您的问题。

但我认为最好不要做这个手术 OnNavagateTo 事件或 Page.Loaded 事件,UWP中没有刷新方法,我们使用再次导航到此页面进行刷新,因此如果将此操作放入 OnNavagate收件人 事件或 页面.已加载 事件,则每次导航到此页面时,资源都将被覆盖,并且它将再次导航。因此,我将此操作放在按钮单击事件中,如下所示:

public bool Reload()
{
    return Reload(null);
}

private bool Reload(object param)
{
    Type type = this.Frame.CurrentSourcePageType;
    if (this.Frame.BackStack.Any())
    {
        type = this.Frame.BackStack.Last().SourcePageType;
        param = this.Frame.BackStack.Last().Parameter;
    }
    try { return this.Frame.Navigate(type, param); }
    finally
    {
        this.Frame.BackStack.Remove(this.Frame.BackStack.Last());
    }
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    ColorExtractor.Analyse();
    Reload();
}

最后,我决定在ColorExtractor中创建一个事件。反恐精英:

public static event EventHandler Analysed;
public async static void  Analyse(BitmapImage poster)
{
    //Analyse colors
    Analysed(null, null);
}

然后,在我的主页.xaml.cs上:

ColorExtractor.Analyse(bmp);
ColorExtractor.Analysed += (sender, EventArgs) =>
{
    //Set Page foreground color, as a lot of controls are dynamically binded to their parent's foreground brush.
    //If a control isn't automatically binded, all I have to do is say: Foreground="{Binding Foreground, ElementName=page}"
    page.Foreground = Application.Current.Resources["SystemControlForegroundAccentBrush"] as SolidColorBrush;
    page.BorderBrush = Application.Current.Resources["SystemControlHighlightAccentBrush"] as SolidColorBrush;
    //Reload any custom user control that sets it's children's color when it's loaded.
    backdrop.UserControl_Loaded(null, null);
};

因此,我实际上并没有直接将控件绑定到ForegroundAccentBrush,但这并不需要重新导航到页面。