Csharp 如何在WinUI 3中手动切换 colored颜色 主题

让我们假设这个组合框是MainPage.xaml.

<ComboBox x:Name="themeMode" SelectionChanged="Themes_SelectionChanged">
    <ComboBoxItem>Light</ComboBoxItem>
    <ComboBoxItem>Dark</ComboBoxItem>
    <ComboBoxItem>Defaut</ComboBoxItem>                    
</ComboBox>

然后在MainPage.xaml.cs分钟内

private void Themes_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    if (sender is ComboBox comboBox &&
        comboBox.SelectedItem is ComboBoxItem comboBoxItem &&
        comboBoxItem.Content is string themeString &&
        Enum.TryParse(themeString, out ElementTheme theme) is true)
    {
        this.RequestedTheme = theme;
    }
}

此外，您可以这样做，而不是手动在XAML中添加项.

在MainPage.xaml年中:

public ImmutableArray<string> ElementThemeOptions { get; } = ImmutableArray.Create(Enum.GetNames<ElementTheme>());

private void Themes_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    if (sender is ComboBox comboBox &&
        comboBox.SelectedValue is string themeString &&
        Enum.TryParse(themeString, out ElementTheme theme) is true)
    {
        this.RequestedTheme = theme;
    }
}

而在MainPage.xaml年:

<ComboBox
    ItemsSource="{x:Bind ElementThemeOptions}"
    SelectionChanged="Themes_SelectionChanged" />

UPDATE个

不要忘记在根页面中执行此操作，在本例中为MainPage.

<Window
    ...
    ...>
    <local:MainPage />
</Window>