动态资源

通过DynamicResource可以实现本地资源的替换，实现多语切换或者主题切换功能。

动态资源

定义资源文件

一个Key为Hello的键值对模拟多语切换

一个Key为ButtonBackground的键值对模拟主题切换

中文资源文件

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:sys="clr-namespace:System;assembly=mscorlib">
    <sys:String x:Key="Hello">您好</sys:String>
    <SolidColorBrush x:Key="ButtonBackground" Color="Orange"></SolidColorBrush>
</ResourceDictionary>

英文资源文件

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:sys="clr-namespace:System;assembly=mscorlib">
    <sys:String x:Key="Hello">Hello</sys:String>
    <SolidColorBrush x:Key="ButtonBackground" Color="Purple" />
</ResourceDictionary>

引用资源文件

默认引用zh-cn.xaml资源文件

<Application
    x:Class="WpfApp1.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="pack://application:,,,/WpfApp1;component/Themes/zh-cn.xaml" />
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

页面

13行代码高亮：绑定Key为ButtonBackground的资源，模拟主题切换

27行代码高亮：绑定Key为Hello的资源，模拟多语切换

29行代码高亮：实现切换功能

<UserControl
    x:Class="WpfApp1.Views.SwitchView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    d:DesignHeight="450"
    d:DesignWidth="800"
    mc:Ignorable="d">
    <UserControl.Resources>
        <Style x:Key="SwitchButton" TargetType="{x:Type Button}">
            <Setter Property="OverridesDefaultStyle" Value="True" />
            <Setter Property="Background" Value="{DynamicResource ButtonBackground}" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type Button}">
                        <Border Background="{TemplateBinding Background}">
                            <ContentPresenter />
                        </Border>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </UserControl.Resources>
    <Grid>
        <StackPanel>
            <TextBlock Text="{DynamicResource Hello}" />
            <Button Content="按钮" Style="{StaticResource SwitchButton}" />
            <Button Click="Button_Click" Content="切换" />
        </StackPanel>
    </Grid>
</UserControl>

切换功能

Application.Current.Resources.MergedDictionaries显示当前使用的所有资源

private void Button_Click(object sender, RoutedEventArgs e)
{
    var sourceXaml= Application.Current.Resources.MergedDictionaries.FirstOrDefault(it=>it.Source.Segments.Contains("zh-cn.xaml"));
    var targetXaml = Application.Current.Resources.MergedDictionaries.FirstOrDefault(it => it.Source.Segments.Contains("en.xaml"));
    Uri addSource = null;
    if(sourceXaml is null && targetXaml is not null)
    {
        sourceXaml = targetXaml;
        addSource = new Uri($"pack://application:,,,/WpfApp1;component/Themes/zh-cn.xaml");
    }
    else if(targetXaml is null)
    {
        addSource = new Uri($"pack://application:,,,/WpfApp1;component/Themes/en.xaml");
    }

    Application.Current.Resources.MergedDictionaries.Remove(sourceXaml);
    Application.Current.Resources.MergedDictionaries.Add(new ResourceDictionary() { Source = addSource });

    Application.Current.MainWindow?.OnApplyTemplate();
}