枚举的多语言显示

关于枚举类型的多语言显示，其实就是Globalization的问题。解决方案当然不止一种，这里介绍一种可用性和扩展性的比较好的通用方法。

 

显然这里自己去实现自定义格式化，即通过IFormatable、IFormatProvider、ICustomFormatter等接口已达到Globalization有点小题大作了，而另外一个很容易想到的点是通过DiaplayMember实现显示值得自定义（对于简单Binding，例如ComboBox、ListBox等只用重载ToString就可以了）。

 

首先，我们希望Binding整个枚举类型的每一个值，也就是说，我们需要把这个枚举的所有值变成一个数据源，为了实现这一点，我们可以使用Enum上的helper方法Enum.GetValues(Type)来返回一个对所有值得枚举，然后依次添加到IList对象或者IListSource接口即可。

 

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if (!typeof(EnumType).IsEnum) {     throw new NotSupportedException("Can not support type: " + typeof(EnumType).FullName);     // It's better use resource version as below.     // throw new NotSupportedException(SR.GetString("TYPE_NOT_SUPPORT",  typeof(EnumType).FullName)); }   // Use Enum helper enumerator list all enum values and add to current context. foreach (EnumType value in Enum.GetValues(typeof(EnumType))) {     //TODO: add each value to IList     base.Add(new EnumAdapter(value)); }

 

然后，取到了值，由于我们希望自定义Binding显示，那么需要对枚举值进行封装，而在这个封装里面，我们可以实现多语言的支持。

 

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/// <summary> ///   Enum value adapter, used to get values from each Cultures. /// </summary> public sealed class EnumAdapter {     /**//// <summary>     ///   Storage the actual Enum value.     /// </summary>     private EnumType _value;       /**//// <summary>     ///   Constructor an <see cref="EnumAdapter"/>.     /// </summary>     /// <param name="value">The enum value.</param>     /// <exception cref="">     ///       /// </exception>     public EnumAdapter(EnumType value)     {         if (!Enum.IsDefined(typeof(EnumType), value))         {             throw new ArgumentException(string.Format("{0} is not defined in {1}", value, typeof(EnumType).Name), "value");             // It's better use resource version as below.             // throw new ArgumentException(SR.GetString("ENUM_NOT_DEFINED_FMT_KEY", value, typeof(EnumType).Name), "value");         }         _value = value;     }       /**//// <summary>     ///   Gets the actual enum value.     /// </summary>     public EnumType Value     {         get { return _value; }     }       /**//// <summary>     ///   Gets the display value for enum value by search local resource with currrent UI lture     ///   and special key which is concated from Enum type name and Enum value name.     /// </summary>     /// <remarks>     ///   This would get correct display value by accessing location resource with current UI Culture.     /// </remarks>     public string DisplayValue     {         get { return SR.GetString(string.Format("{0}.{1}", typeof(EnumType).Name, _value.ToString())); }     }       //TODO: If you want more, please add below }

 

至此，整个功能的框架已经完成，下面我们来看看一些细节——如何对资源读取和管理的封装：

 

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/// <summary> ///   Constructor a new <see cref="SR"/>. /// </summary> internal SR() {     //TODO: If you modified resource location, please update here     this.resources = new System.Resources.ResourceManager(         string.Concat(typeof(EnumAdapter).Namespace, ".Resource"),         base.GetType().Assembly); }   /**//// <summary> ///   Get singleton instance. /// </summary> /// <returns>A singleton <see cref="SR"/></returns> private static SR GetLoader() {     if (loader == null)     {         lock (SR.InternalSyncObject)         {             if (loader == null)             {                 loader = new SR();             }         }     }     return loader; }   /**//// <summary> ///   Gets an object from resources by special key, which provided by <paramref name="name"/>. /// </summary> /// <param name="name">Resource accessed key</param> /// <returns>return stored object in resource. if resource not found, return <paramref name="name"/> as object.</returns> public static object GetObject(string name) {     SR loader = GetLoader();     if (loader == null)     {         return null;     }     try     {         return loader.resources.GetObject(name, Culture);     }     catch { }     return name; }   /**//// <summary> ///   Gets a string from resources by special key, which provided by <paramref name="name"/>. /// </summary> /// <param name="name">Resource accessed key</param> /// <returns>return stored string in resource. If resource not found, retuen <paramref name="name"/> as result.</returns> public static string GetString(string name) {     SR loader = GetLoader();     if (loader == null)     {         return null;     }     try     {         return loader.resources.GetString(name, Culture);     }     catch { }     return name; }   /**//// <summary> ///   Gets a formatted string from resources by special key, which provided by <paramref name="name"/> and optional parameters. /// </summary> /// <param name="name">Resource accessed key</param> /// <param name="args">format arguments.</param> /// <returns>return stored string in resource. If resource not found, use <paramref name="name"/> as formator, return the formatted string.</retur public static string GetString(string name, params object[] args) {     SR loader = GetLoader();     if (loader == null)     {         return null;     }     string format = name;     try     {         format = loader.resources.GetString(name, Culture);     }     catch { }       if ((args == null) || (args.Length <= 0))     {         return format;     }       // It's better cut long arg for formating.     for (int i = 0; i < args.Length; i++)     {         string arg = args[i] as string;         if ((arg != null) && (arg.Length > 0x400))         {             args[i] = arg.Substring(0, 0x3fd) + "";         }     }     return string.Format(System.Globalization.CultureInfo.CurrentCulture, format, args); }

 

OK，大功告成，有了这么一个封装，在应用里就可以简单的这么几句够搞定。

 

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private void Form1_Load(object sender, EventArgs e) {     this.comboBox1.DataSource = new EnumDataSource<Sex>();     this.comboBox1.DisplayMember = "DisplayValue";     this.comboBox1.ValueMember = "Value"; }   public enum Sex {     Male,     Female }