文章目录
- 第一步:基础实现,资源文件入门
- 第二步:依赖属性,提升WPF体验
- 第三步:多页面复用,减少重复代码
- 第四步:动态化,应对更多字符串
- 总结与反思
作为一名WPF开发者,我最近在一个配置工具项目中遇到了国际化需求。起初,我只是想让按钮文本支持英文和中文切换,但随着页面增多,需求复杂化,我逐渐摸索出一套从简单到专业化的实现方案。这篇文章记录了我的探索过程,从最基础的资源文件开始,到多页面复用的优化,希望能给有类似需求的开发者一些启发。
第一步:基础实现,资源文件入门
我的项目是一个基于WPF和MVVM的配置工具,界面上有“Save”和“Refresh”两个按钮,需要支持英文和中文切换。WPF的国际化通常从资源文件(.resx)入手,于是我先尝试了最简单的方法。
在项目中,我创建了一个Resources文件夹,添加了两个资源文件:
- Resources.resx(默认英文):
- save: Save
- refresh: Refresh
- Resources.zh-CN.resx(中文):
- save: 保存
- refresh: 刷新
在XAML中,我尝试直接绑定到资源:
<Button Content="{Binding Source={x:Static local:Resources.save}}" />
但很快发现,这种方式在运行时切换语言时不会更新UI,因为静态绑定无法响应动态变化。于是,我转向代码隐藏文件,在UserControl中定义属性:
public partial class PageTemplate : UserControl
{public string Save => Resources.ResourceManager.GetString("save");public string Refresh => Resources.ResourceManager.GetString("refresh");public PageTemplate(){InitializeComponent();DataContext = this;}
}
XAML改为:
<Button Content="{Binding Save}" />
这时候,按钮显示了英文,但点击“中文”按钮后,文本没变。我意识到,语言切换需要更新CultureInfo,于是引入了一个单例类LanguageManager:
public class LanguageManager
{private static readonly Lazy<LanguageManager> _instance = new Lazy<LanguageManager>(() => new LanguageManager());public static LanguageManager Instance => _instance.Value;private CultureInfo _currentCulture = new CultureInfo("en-US");public CultureInfo CurrentCulture{get => _currentCulture;set{_currentCulture = value;Thread.CurrentThread.CurrentUICulture = value;}}public string GetString(string key) => Resources.ResourceManager.GetString(key, _currentCulture) ?? $"[{key}]";
}
在PageTemplate中使用:
private readonly LanguageManager _languageManager = LanguageManager.Instance;
public string Save => _languageManager.GetString("save");
加上切换命令:
<Button CommandParameter="zh-CN" Command="{Binding SwitchLanguageCommand}" Content="中文" />
public ICommand SwitchLanguageCommand => new RelayCommand<string>(lang =>
{_languageManager.CurrentCulture = new CultureInfo(lang);
});
然而,切换后UI还是没更新。我调试发现,虽然CultureInfo变了,但绑定没有刷新。加上INotifyPropertyChanged后问题解决:
public partial class PageTemplate : UserControl, INotifyPropertyChanged
{private readonly LanguageManager _languageManager = LanguageManager.Instance;public string Save => _languageManager.GetString("save");public PageTemplate(){InitializeComponent();DataContext = this;_languageManager.PropertyChanged += (s, e) => OnPropertyChanged(null);}public event PropertyChangedEventHandler PropertyChanged;protected void OnPropertyChanged(string propertyName) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
终于,切换语言时按钮文本正常更新了!
第二步:依赖属性,提升WPF体验
虽然基础功能实现了,但这种只读属性方式让我觉得不够“WPF”。在WPF中,依赖属性更适合绑定场景。于是我改用依赖属性:
public static readonly DependencyProperty SaveProperty = DependencyProperty.Register(nameof(Save), typeof(string), typeof(PageTemplate), new PropertyMetadata(string.Empty));public string Save
{get => (string)GetValue(SaveProperty);set => SetValue(SaveProperty, value);
}public PageTemplate()
{InitializeComponent();DataContext = this;UpdateLocalizedStrings();_languageManager.PropertyChanged += (s, e) => UpdateLocalizedStrings();
}private void UpdateLocalizedStrings()
{Save = _languageManager.GetString("save");Refresh = _languageManager.GetString("refresh");
}
这样,绑定更符合WPF的习惯,而且UI更新更可靠。下一步,我把语言切换按钮改成了下拉框:
<ComboBox ItemsSource="{Binding Languages}"DisplayMemberPath="DisplayName"SelectedValuePath="CultureName"SelectedValue="{Binding SelectedLanguage, Mode=TwoWay}"/>
public List<LanguageOption> Languages { get; } = new List<LanguageOption>
{new LanguageOption("English", "en-US"),new LanguageOption("中文", "zh-CN")
};public static readonly DependencyProperty SelectedLanguageProperty = DependencyProperty.Register(nameof(SelectedLanguage), typeof(string), typeof(PageTemplate),new PropertyMetadata("en-US", OnSelectedLanguageChanged));public string SelectedLanguage
{get => (string)GetValue(SelectedLanguageProperty);set => SetValue(SelectedLanguageProperty, value);
}private static void OnSelectedLanguageChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{var page = (PageTemplate)d;page._languageManager.CurrentCulture = new CultureInfo((string)e.NewValue);
}
这让界面更友好,用户体验也提升了。
第三步:多页面复用,减少重复代码
项目发展到有多个页面时,我发现每个页面都重复定义Save、Refresh和语言切换逻辑,太繁琐了。我决定把国际化集中化,先创建了一个基类:
public class BaseViewModel : INotifyPropertyChanged
{protected readonly LanguageService _languageService = LanguageService.Instance;public string Save => _languageService.GetString("save");public string Refresh => _languageService.GetString("refresh");public event PropertyChangedEventHandler PropertyChanged;protected void OnPropertyChanged(string propertyName) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
LanguageService接管了语言管理:
public class LanguageService : INotifyPropertyChanged
{private static readonly Lazy<LanguageService> _instance = new Lazy<LanguageService>(() => new LanguageService());public static LanguageService Instance => _instance.Value;private CultureInfo _currentCulture = new CultureInfo("en-US");public CultureInfo CurrentCulture{get => _currentCulture;set{_currentCulture = value;Thread.CurrentThread.CurrentUICulture = value;OnPropertyChanged(null);}}public string GetString(string key) => Resources.ResourceManager.GetString(key, _currentCulture) ?? $"[{key}]";public List<LanguageOption> Languages { get; } = new List<LanguageOption>{new LanguageOption("English", "en-US"),new LanguageOption("中文", "zh-CN")};public string SelectedLanguage{get => _currentCulture.Name;set => CurrentCulture = new CultureInfo(value);}public event PropertyChangedEventHandler PropertyChanged;protected void OnPropertyChanged(string propertyName) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
页面只需继承BaseViewModel:
public class PageTemplateViewModel : BaseViewModel { }
public partial class PageTemplate : UserControl
{public PageTemplate(){InitializeComponent();DataContext = new PageTemplateViewModel();}
}
XAML绑定到全局服务:
<ComboBox ItemsSource="{Binding Languages, Source={x:Static services:LanguageService.Instance}}"SelectedValue="{Binding SelectedLanguage, Source={x:Static services:LanguageService.Instance}, Mode=TwoWay}"/>
第四步:动态化,应对更多字符串
页面越来越多,字符串也从save、refresh扩展到title、user等十几个。我不想在BaseViewModel中为每个字符串写属性,于是尝试了动态方案:
public class BaseViewModel : INotifyPropertyChanged
{protected readonly LanguageService _languageService = LanguageService.Instance;public dynamic Strings => new LocalizedStrings(_languageService);public BaseViewModel(){_languageService.PropertyChanged += (s, e) => OnPropertyChanged(nameof(Strings));}public event PropertyChangedEventHandler PropertyChanged;protected void OnPropertyChanged(string propertyName) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}public class LocalizedStrings : DynamicObject
{private readonly LanguageService _languageService;public LocalizedStrings(LanguageService languageService){_languageService = languageService;}public override bool TryGetMember(GetMemberBinder binder, out object result){result = _languageService.GetString(binder.Name.ToLower());return true;}
}
XAML改为:
<Button Content="{Binding Strings.save}" />
<TextBlock Text="{Binding Strings.title}" />
现在,无论有多少字符串,我只需在资源文件里添加键值对,代码完全不用改动。这种方式让我从繁琐的属性定义中解放出来。
总结与反思
从最初的简单资源文件,到依赖属性,再到多页面复用,最后用动态对象优化,我的国际化之旅走了不少弯路,但每一步都让我更理解WPF和MVVM的精髓:
- 起步简单:资源文件和基本绑定能快速实现单页面国际化。
- 提升体验:依赖属性和下拉框让切换更自然。
- 复用为王:集中化管理避免重复劳动。
- 动态扩展:用动态对象应对未来需求。
如果你的项目也有国际化需求,不妨从基础开始,根据规模逐步优化。你遇到过哪些国际化难题?欢迎留言分享!