EnumPicker

The EnumPicker control allows for the input of an Enum value using a standard list presentation. It supports both flags and non-flags enumerations, altering the user interface as appropriate.

The EnumPicker directly embeds an EnumListBox control to provide the functionality mentioned above.

Enumeration Value and Type

The Value property provides a quick and easy way to setup to the list box. The EnumType property is used to build the items presented by the EnumPicker. The items are constructed by reflecting the enumeration type, with full support for the FlagsAttribute.

When the Value property is bound/set to a non-null enumeration value, then the enumeration type will be automatically set (if it has not been explicitly set). Therefore, the EnumType only needs to be set when Value is bound to a nullable enumeration type.

Using Display Attributes

Sometimes it is helpful to display an alternate text version of an enumeration value, especially when the values are made of multiple concatenated words. For instance, an enumeration value named FirstName might appear nicer as "First Name".

This scenario is fully supported by EnumPicker. A System.ComponentModel.DataAnnotations.DisplayAttribute can be applied to a value to give it an alternate textual description. Then as long as the UseDisplayAttributes property is set to true, that alternate text will be used.

If the DisplayAttribute.ResourceType property is left blank, it will use the direct value specified by the Name property. Otherwise, it will look in the specified resource Type for a localized resource value within the property indicated by Name. If the Name property is undefined, the ShortName property will be used instead.

In this example, the DisplayAttribute will look for a property named MyFirstValue in the string resources type MyResources and use that property's value:

public enum SampleEnum {

	[Display(ResourceType = typeof(MyResources), Name = "MyFirstValue")]
	MyFirstValue = 1

	...
}

Custom Sorting

By default, values are listed in the order they are defined. The exception is that in flags enumerations, group values get placed together.

Sorting can be altered by implementing a custom IComparer<Enum> class and assigning it to the EnumSortComparer property. The EnumValueNameSortComparer.Instance static property provides access to a pre-built comparer for listing enumeration values alphabetically by name.

Alternatively, the DisplayAttribute.Order property can be used to define the sort order if the UseDisplayAttributes property is set to true and a custom EnumSortComparer is undefined. Values that define a DisplayAttribute.Order will always be sorted before values that do not define the attribute.

Hiding Enumeration Values

By default, all values are listed in the control. If you wish to hide a specific value from the end user, use EditorBrowsableAttribute on the value with EditorBrowsableState.Never.

In this example, the EditorBrowsableAttribute hides the MyFirstValue value from the user interface:

public enum SampleEnum {

	[EditorBrowsable(EditorBrowsableState.Never)]
	MyFirstValue = 1

	...
}

Sample XAML

This control can be placed within any other XAML container control, such as a Page or Panel with this sort of XAML:

<editors:EnumPicker Value="{Binding Path=YourVMProperty, Mode=TwoWay}" />