使枚舉類型的選項在VS的屬性窗裏顯示爲中文

     我們自己做的組件，一般希望它的屬性在設計時能夠在屬性窗裏顯示爲中文，可以在屬性上添加System.ComponentModel.DisplayNameAttribute標註達到這個目的。但是，枚舉的選項如何以中文的形式顯示在屬性窗裏呢？

     假設我們有如下枚舉：

public enum MyEnum
{
    A,
    B
}

     在某個組件裏有一個MyEnum類型的屬性，如下：

   1: [DisplayName("我的枚舉")]

   2:  public MyEnum MyEnum

   3:  {

   4:      get;set;

   5:  }

     在設計時把這個組件拖到設計器中，發現屬性窗中出現了“我的枚舉”這個屬性，但選項是A和B，如何讓它們示爲“選項一”和“選項二”呢？這就需要利用到TypeConverter了，因爲PropertyGrid利用TypeConverter來顯示枚舉的選項的。另外，爲了使擴展性更好，我們還需要DescriptionAttribute.

     繼承System.ComponentModel.EnumConverter，實現自己的Converter，如下：

   1: public class MyEnumConverter : EnumConverter

   2: {

   3:     private IDictionary<object, string> dic;

   4:     private IDictionary<string, object> dic2;

   5:     private readonly Type type = typeof(MyEnum);

   6:  

   7:     public MyEnumConverter()

   8:         : base(typeof(MyEnum))

   9:     {

  10:     }

  11:     

  12:  

  13:     public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)

  14:     {

  15:         if(value is string)

  16:         {

  17:             if(dic2 != null && dic2.ContainsKey(value as string))

  18:             {

  19:                 return dic2[value as string];

  20:             }

  21:         }

  22:         return base.ConvertFrom(context, culture, value);

  23:     }

  24:  

  25:     public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)

  26:     {

  27:         if(destinationType == typeof(string))

  28:         {

  29:             if(dic == null)

  30:             {

  31:                 dic = new Dictionary<object, string>();

  32:                 dic2 = new Dictionary<string, object>();

  33:                 Type reflectionType = TypeDescriptor.GetReflectionType(this.type);

  34:                 if (reflectionType == null)

  35:                 {

  36:                     reflectionType = this.type;

  37:                 }

  38:                 FieldInfo[] fields = reflectionType.GetFields(BindingFlags.Public | BindingFlags.Static);

  39:                 ArrayList list = null;

  40:                 if ((fields != null) && (fields.Length > 0))

  41:                 {

  42:                     list = new ArrayList(fields.Length);

  43:                 }

  44:                 if (list != null)

  45:                 {

  46:                     foreach (FieldInfo info in fields)

  47:                     {

  48:                         object fieldValue = info.GetValue(info);

  49:                         string desc = fieldValue.ToString();

  50:                         DescriptionAttribute descriptionAttribute = null;

  51:                         foreach (DescriptionAttribute a in info.GetCustomAttributes(typeof(DescriptionAttribute), false))

  52:                         {

  53:                             descriptionAttribute = a;

  54:                             break;

  55:                         }

  56:                         if (descriptionAttribute != null)

  57:                         {

  58:                             desc = descriptionAttribute.Description;

  59:                         }

  60:                         dic[fieldValue] = desc;

  61:                         dic2[desc] = fieldValue;

  62:                     }

  63:                 }

  64:             }

  65:             return dic[value];

  66:         }

  67:         

  68:         return base.ConvertTo(context, culture, value, destinationType);

  69:     }

  70: }

     然後修改MyEnum，如下：

   1: public enum MyEnum

   2: {

   3:     [Description("選項一")]

   4:     A,

   5:     [Description("選項二")]

   6:     B

   7: }

     並且修改組件裏的屬性，加入TypeConverterAttribute，如下：

   1: [DisplayName("我的枚舉")]

   2: [TypeConverter(typeof(MyEnumConverter))]

   3: public MyEnum MyEnum

   4: {

   5:     get;

   6:     set;

   7: }

     這樣，就可以以中文的形式在屬性窗裏顯示枚舉的選項了，如下圖：