Enum: Binding to the Description Attribute

re: Enum: Binding to the Description Attribute

Nico — Thu, 03 Dec 2009 11:11:37 GMT

Hi Deborah,

Is there a way to make this work in a datagridview comboboxColumn?

Thanx,

Nico

re: Enum: Binding to the Description Attribute

Rob — Thu, 30 Jul 2009 18:21:04 GMT

Deborah,

your solution is lacking of a sort (orderby) metod. Check my ListKeyValuePairEx which you can change for Dictionaries as well:

To use:

<combobox>.BindEnumKeyValue(typeof(<enum>));

<combobox>.BindEnumDescriptionValue(typeof(<enum>));

public static class ComboBoxEx

{

public static void BindEnumKeyValue(this ComboBox obj, Type enumType)

{

obj.DataSource = enumType.EnumToList();

obj.DisplayMember = "Key";

obj.ValueMember = "Value";

}

public static void BindEnumDescriptionValue(this ComboBox obj, Type enumType)

{

obj.DataSource = enumType.EnumDescriptionToList();

obj.DisplayMember = "Key";

obj.ValueMember = "Value";

}

public static class EnumEx

{

public static IList EnumToList(this Type enumType)

{

List<KeyValuePair<string, int>> list = new List<KeyValuePair<string, int>>();

foreach (Enum key in Enum.GetValues(enumType))

{

int value = (int)Enum.Parse(enumType, key.ToString());

list.AddUnique(new KeyValuePair<string, int>(key.ToString(), value));

}

return list.SortByKey();

}

public static IList EnumDescriptionToList(this Type enumType)

{

List<KeyValuePair<string, int>> list = new List<KeyValuePair<string, int>>();

foreach (Enum key in Enum.GetValues(enumType))

{

int value = (int)Enum.Parse(enumType, key.ToString());

list.AddUnique(new KeyValuePair<string, int>(key.GetEnumDescription(), value));

}

return list.SortByKey();

}

public static string GetEnumDescription(this Enum value)

{

return GetEnumAttribute(value, typeof(DescriptionAttribute));

}

public static string GetEnumCategory(this Enum value)

{

return GetEnumAttribute(value, typeof(CategoryAttribute));

}

public static string GetEnumAttribute(this Enum value, Type attribute)

{

Type type = value.GetType();

if (value == null)

{

throw new ArgumentException("Value must be of type Enum", "Value");

}

System.Reflection.MemberInfo[] memberInfo = type.GetMember(value.ToString());

if (memberInfo != null && memberInfo.Length > 0)

{

object[] attrs = memberInfo[0].GetCustomAttributes(attribute, false);

if (attrs != null && attrs.Length > 0)

{

return ((DescriptionAttribute)attrs[0]).Description;

}

return value.ToString();

}

public static class ListKeyValuePairEx

{

public static List<KeyValuePair<K, V>> AddUnique<K, V>(this List<KeyValuePair<K, V>> list, KeyValuePair<K, V> kv)

{

if (!list.Contains(kv))

list.Add(kv);

return list;

}

public static List<KeyValuePair<K, V>> SortByKey<K, V>(this List<KeyValuePair<K, V>> list)

{

List<KeyValuePair<K, V>> sorted = new List<KeyValuePair<K, V>>();

foreach (KeyValuePair<K, V> item in list.OrderBy(key => key.Key))

{

sorted.Add(new KeyValuePair<K, V>(item.Key, item.Value));

}

return sorted;

}

public static List<KeyValuePair<K, V>> SortByValue<K, V>(this List<KeyValuePair<K, V>> list)

{

List<KeyValuePair<K, V>> sorted = new List<KeyValuePair<K, V>>();

foreach (KeyValuePair<K, V> item in list.OrderBy(key => key.Value))

{

sorted.Add(new KeyValuePair<K, V>(item.Key, item.Value));

}

return sorted;

}

re: Enum: Binding to the Description Attribute

Deborah Kurata — Tue, 21 Jul 2009 22:14:38 GMT

Hi Paul -

If you have to support multiple languages in your UI, you should not have any strings that you plan to display to the user hard-coded in the code.

So you won't be able to leverage this technique.

re: Enum: Binding to the Description Attribute

Deborah Kurata — Thu, 16 Jul 2009 23:19:02 GMT

Very cool, Yann.

Thanks!

re: Enum: Binding to the Description Attribute

Yann — Thu, 16 Jul 2009 12:57:49 GMT

Hi Deborah,

Thanks, this was just what I needed!

However, instead of using a dictionary as you did, I used LINQ with an anonymous type.

Dim enums = [Enum].GetValues(_type)

result = _

( _

From e As Object In enums _

Select e = New With _

{ _

.ID = CInt(e) _

, .Name = CType(e, [Enum]).GetDescription _

} _

Order By _

e.Name _

).ToList

I had already created an extension method "ToWords" for the string type (which I didn't show here for simplicity), but I needed to have "Week 1/2", "Week 3/4" which of course I couldn't have as enum members.

So your code helped me out enormously!

Thanks,

Yann

re: Enum: Binding to the Description Attribute

Deborah Kurata — Mon, 13 Jul 2009 17:15:31 GMT

Hi Moggoly -

Thank you for your post. My extension method just extended [Enum]. It would be interesting to see how you did it with a generic extension method. Would you be willing to post some of your code?

Thanks again!

re: Enum: Binding to the Description Attribute

Moggoly — Sun, 12 Jul 2009 11:47:19 GMT

I wrote about this same solution over a year ago - with a slight difference in that my solution is using a generic extension method to get the description attribute value.

re: Enum: Binding to the Description Attribute

paul — Sat, 11 Jul 2009 19:49:56 GMT

Great !

How using this in a multi-language context?