【WPF】 本地化的最佳做法

  应用程序本地化有很多种方式，选择合适的才是最好的。这里只讨论一种方式，动态资源（DynamicResource） 这种方式可是在不重启应用程序的情况下进行资源的切换，不论是语言切换，还是更上层的主题切换。想要运行时切换不同的资源就必须使用 动态资源（DynamicResource） 这种方式。
图片是可以使用资源字典进行动态 binding 的 不要被误导了

资源文件

确保不同语言环境中资源 Key 是同一个，且对用的资源类型是相同的。
在资源比较多的情况下，可以通过格式化的命名方式来规避 Key 冲突。

资源文件的属性可以设置成：
生成操作：内容
复制到输出目录：如果较新则复制

上面的操作可以在不重新编译程序的情况下编辑语言资源并应用。

如果不想让别人更改语言资源则
生成操作：页
复制到输出目录：不复制

英文资源文件 en-US.xaml

<ResourceDictionaryxmlns="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="WindowsTitle">MainWindow</sys:String><ImageSource x:Key="icon">pack://SiteOfOrigin:,,,/Icons/en-USicon.png</ImageSource><sys:String x:Key="LanguageButton">LanguageButton</sys:String><sys:String x:Key="LockTime-OneMinute">1 Minute</sys:String><sys:String x:Key="LockTime-FiveMinute">5 Minute</sys:String><sys:String x:Key="LockTime-TenMinute">10 Minute</sys:String><sys:String x:Key="LockTime-FifteenMinute">15 Minute</sys:String><sys:String x:Key="LockTime-ThirtyMinute">30 Minute</sys:String><sys:String x:Key="LockTime-OneHour">1 Hour</sys:String><sys:String x:Key="LockTime-TwoHour">2 Hour</sys:String><sys:String x:Key="LockTime-ThreeHour">3 Hour</sys:String><sys:String x:Key="LockTime-Never">Never</sys:String>
</ResourceDictionary>

中文资源文件 zh-CN.xaml

<ResourceDictionaryxmlns="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="WindowsTitle">主窗口</sys:String><ImageSource x:Key="icon">pack://SiteOfOrigin:,,,/Icons/zh-CNicon.png</ImageSource><sys:String x:Key="LanguageButton">语言按钮</sys:String><sys:String x:Key="LockTime-OneMinute">1 分钟</sys:String><sys:String x:Key="LockTime-FiveMinute">5 分钟</sys:String><sys:String x:Key="LockTime-TenMinute">10 分钟</sys:String><sys:String x:Key="LockTime-FifteenMinute">15 分钟</sys:String><sys:String x:Key="LockTime-ThirtyMinute">30 分钟</sys:String><sys:String x:Key="LockTime-OneHour">1 小时</sys:String><sys:String x:Key="LockTime-TwoHour">2 小时</sys:String><sys:String x:Key="LockTime-ThreeHour">3 小时</sys:String><sys:String x:Key="LockTime-Never">永不</sys:String>
</ResourceDictionary>

资源使用

App.xaml

设置默认语言资源，用于在设计阶段预览，并利用 VS 智能提示资源的 Key 防止 Key编写出错。

<Applicationx:Class="Localization.Core.App"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:local="clr-namespace:Localization.Core"StartupUri="MainWindow.xaml"><Application.Resources><ResourceDictionary><ResourceDictionary.MergedDictionaries><ResourceDictionary Source="/I18nResources/en-US.xaml" /></ResourceDictionary.MergedDictionaries></ResourceDictionary></Application.Resources>
</Application>

主界面布局

<Windowx:Class="Localization.Core.MainWindow"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:local="clr-namespace:Localization.Core"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"xmlns:operate="clr-namespace:Localization.Core.Operates"Title="{DynamicResource WindowsTitle}"Width="800"Height="450"Icon="{DynamicResource icon}"mc:Ignorable="d"><Grid><Grid.RowDefinitions><RowDefinition Height="Auto" /><RowDefinition /></Grid.RowDefinitions><ComboBoxx:Name="comLan"Width="{Binding SizeToContent.Width}"Height="{Binding SizeToContent.Width}"HorizontalAlignment="Center"VerticalAlignment="Center"SelectedValuePath="Tag"SelectionChanged="ComboBox_SelectionChanged"><ComboBoxItem Content="中文" Tag="zh-CN" /><ComboBoxItem Content="English" Tag="en-US" /></ComboBox><StackPanel Grid.Row="1"><ButtonMargin="0,50,0,0"HorizontalAlignment="Center"VerticalAlignment="Center"Content="{DynamicResource LanguageButton}" /><ComboBoxx:Name="cmTime"Width="120"Margin="20"VerticalAlignment="Center"><ComboBox.ItemTemplate><DataTemplate><TextBlock Text="{operate:ResourceBinding Key}" /></DataTemplate></ComboBox.ItemTemplate></ComboBox></StackPanel></Grid>
</Window>

cs代码

public partial class MainWindow : Window
{ObservableCollection<KeyValuePair<string, int>>? TimeList { get; set; }public MainWindow(){InitializeComponent();var lan = Thread.CurrentThread.CurrentCulture.Name;comLan.SelectedValue = lan;Loaded += MainWindow_Loaded;}private void MainWindow_Loaded(object sender, RoutedEventArgs e){TimeList = new ObservableCollection<KeyValuePair<string, int>>(){new KeyValuePair<string, int>("LockTime-OneMinute", 1),new KeyValuePair<string, int>("LockTime-FiveMinute", 5),new KeyValuePair<string, int>("LockTime-TenMinute", 10),new KeyValuePair<string, int>("LockTime-FifteenMinute", 15),new KeyValuePair<string, int>("LockTime-ThirtyMinute", 30),new KeyValuePair<string, int>("LockTime-OneHour", 60),new KeyValuePair<string, int>("LockTime-TwoHour", 120),new KeyValuePair<string, int>("LockTime-ThreeHour", 180),new KeyValuePair<string, int>("LockTime-Never", 0),};cmTime.ItemsSource = TimeList;cmTime.SelectedValue = TimeList[0];}private void ComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e){if (e.AddedItems is null) return;LanguageOperate.SetLanguage((e.AddedItems[0] as ComboBoxItem)!.Tag.ToString()!);}
}

App.config

language 配置项用于保存用户选择的语言类型

<?xml version="1.0" encoding="utf-8" ?>
<configuration><appSettings><add key="language" value=""/></appSettings>
</configuration>

辅助类

语言切换操作类

检查方法入参，有值则切换到指定的资源，无值则读取配置文件中的值，若配置文件中仍无值，则获取当前线程运行的语言环境，切换到与语言环境相匹配的资源，如果没有找到与之匹配的资源则不做操作。

切换资源之后，将配置文件中的 language 的 value 改为当前所选的语言保存并刷新配置文件，直到下次更改。

重写 Application 类的 OnStartup 方法，在 OnStartup 中调用 SetLanguage 方法以实现应用程序启动对语言环境的判别。

/// <summary>
/// 语言操作
/// </summary>
public class LanguageOperate
{private const string KEY_OF_LANGUAGE = "language";/// <summary>/// 语言本地化/// </summary>/// <param name="language">语言环境</param>public static void SetLanguage(string language = ""){if (string.IsNullOrWhiteSpace(language)){language = ConfigurationManager.AppSettings[KEY_OF_LANGUAGE]!;if (string.IsNullOrWhiteSpace(language))language = System.Globalization.CultureInfo.CurrentCulture.ToString();}string languagePath = $@"I18nResources\{language}.xaml";if (!System.IO.File.Exists(languagePath)) return;var lanRd = Application.LoadComponent(new Uri(languagePath, UriKind.RelativeOrAbsolute)) as ResourceDictionary;var old = Application.Current.Resources.MergedDictionaries.FirstOrDefault(o => o.Contains("WindowsTitle"));if (old != null)Application.Current.Resources.MergedDictionaries.Remove(old);Application.Current.Resources.MergedDictionaries.Add(lanRd);Configuration configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);configuration.AppSettings.Settings[KEY_OF_LANGUAGE].Value = language;configuration.Save();ConfigurationManager.RefreshSection("AppSettings");var culture = new System.Globalization.CultureInfo(language);System.Globalization.CultureInfo.CurrentCulture = culture;System.Globalization.CultureInfo.CurrentUICulture = culture;}
}

资源 binding 解析类

ComBox 控件通常是通过 ItemSource 进行绑定，默认情况下是无法对绑定的资源进行翻译的。
通过继承 MarkupExtension 类 重写 ProvideValue 方法来实现，item 绑定 资源的 Key 的解析。

/// <summary>
/// markup extension to allow binding to resourceKey in general case
/// </summary>
public class ResourceBinding : MarkupExtension
{#region propertiesprivate static DependencyObject resourceBindingKey;public static DependencyObject ResourceBindingKey{get => resourceBindingKey;set => resourceBindingKey = value;}// Using a DependencyProperty as the backing store for ResourceBindingKeyHelper.  This enables animation, styling, binding, etc...public static readonly DependencyProperty ResourceBindingKeyHelperProperty =DependencyProperty.RegisterAttached(nameof(ResourceBindingKey),typeof(object),typeof(ResourceBinding),new PropertyMetadata(null, ResourceKeyChanged));static void ResourceKeyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e){if (!(d is FrameworkElement target) || !(e.NewValue is Tuple<object, DependencyProperty> newVal)) return;var dp = newVal.Item2;if (newVal.Item1 == null){target.SetValue(dp, dp.GetMetadata(target).DefaultValue);return;}target.SetResourceReference(dp, newVal.Item1);}#endregionpublic ResourceBinding() { }public ResourceBinding(string path) => Path = new PropertyPath(path);public override object ProvideValue(IServiceProvider serviceProvider){if ((IProvideValueTarget)serviceProvider.GetService(typeof(IProvideValueTarget)) == null) return null;if (((IProvideValueTarget)serviceProvider.GetService(typeof(IProvideValueTarget))).TargetObject != null && ((IProvideValueTarget)serviceProvider.GetService(typeof(IProvideValueTarget))).TargetObject.GetType().FullName is "System.Windows.SharedDp") return this;if (!(((IProvideValueTarget)serviceProvider.GetService(typeof(IProvideValueTarget))).TargetObject is FrameworkElement targetObject) || !(((IProvideValueTarget)serviceProvider.GetService(typeof(IProvideValueTarget))).TargetProperty is DependencyProperty targetProperty)) return null;#region bindingBinding binding = new Binding{Path = Path,XPath = XPath,Mode = Mode,UpdateSourceTrigger = UpdateSourceTrigger,Converter = Converter,ConverterParameter = ConverterParameter,ConverterCulture = ConverterCulture,FallbackValue = FallbackValue};if (RelativeSource != null)binding.RelativeSource = RelativeSource;if (ElementName != null)binding.ElementName = ElementName;if (Source != null)binding.Source = Source;#endregionvar multiBinding = new MultiBinding{Converter = HelperConverter.Current,ConverterParameter = targetProperty};multiBinding.Bindings.Add(binding);multiBinding.NotifyOnSourceUpdated = true;targetObject.SetBinding(ResourceBindingKeyHelperProperty, multiBinding);return null;}#region Binding Members/// <summary>/// The source path (for CLR bindings)./// </summary>public object Source { get; set; }/// <summary>/// The source path (for CLR bindings)./// </summary>public PropertyPath Path { get; set; }/// <summary>/// The XPath path (for XML bindings)./// </summary>[DefaultValue(null)]public string XPath { get; set; }/// <summary>/// Binding mode/// </summary>[DefaultValue(BindingMode.Default)]public BindingMode Mode { get; set; }/// <summary>/// Update type/// </summary>[DefaultValue(UpdateSourceTrigger.Default)]public UpdateSourceTrigger UpdateSourceTrigger { get; set; }/// <summary>/// The Converter to apply/// </summary>[DefaultValue(null)]public IValueConverter Converter { get; set; }/// <summary>/// The parameter to pass to converter./// </summary>/// <value></value>[DefaultValue(null)]public object ConverterParameter { get; set; }/// <summary>/// Culture in which to evaluate the converter/// </summary>[DefaultValue(null)][TypeConverter(typeof(System.Windows.CultureInfoIetfLanguageTagConverter))]public CultureInfo ConverterCulture { get; set; }/// <summary>/// Description of the object to use as the source, relative to the target element./// </summary>[DefaultValue(null)]public RelativeSource RelativeSource { get; set; }/// <summary>/// Name of the element to use as the source/// </summary>[DefaultValue(null)]public string ElementName { get; set; }#endregion#region BindingBase Members/// <summary>/// Value to use when source cannot provide a value/// </summary>/// <remarks>/// Initialized to DependencyProperty.UnsetValue; if FallbackValue is not set, BindingExpression/// will return target property's default when Binding cannot get a real value./// </remarks>public object FallbackValue { get; set; }#endregion#region Nested typesprivate class HelperConverter : IMultiValueConverter{public static readonly HelperConverter Current = new HelperConverter();public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture){return Tuple.Create(values[0], (DependencyProperty)parameter);}public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture){throw new NotImplementedException();}}#endregion
}

实现效果