I saw a lot of posts on how to bind an enum to a combobox using code behind and C#, but since I was using MVVM, I needed a different solution. I basically wanted to bind a list of the enums in a maintenance view model, and have the the xaml handle the binding of the item list. To help remember what I did and help whomever along the way with the same issue, I thought I would write about it.
Let’s start off with a basic enumeration :
5 | [Description("Medium")] |
Now make that enumeration into a collection in your maintenance view model (or where ever you bind the lists on your comboboxes, etc…). There are a few ways to do this, I just replicated what I’ve done with other collections, just with a little twist to get the descriptions.
1 | private List<keyvaluepair<string,<span class="hiddenSpellError">VolumeLevel>> _VolumeLevelList; |
2 | public List<keyvaluepair<string,<span class="hiddenSpellError">VolumeLevel>> VolumeLevelList |
6 | if (_VolumeLevelList == null) |
8 | _VolumeLevelList = new List<KeyValuePair<string, VolumeLevel>>(); |
9 | foreach (VolumeLevel level in Enum.GetValues(typeof(VolumeLevel))) |
12 | FieldInfo fieldInfo = level.GetType().GetField(level.ToString()); |
13 | DescriptionAttribute[] attributes = (DescriptionAttribute[])fieldInfo.GetCustomAttributes(typeof(DescriptionAttribute), false); |
14 | if (attributes != null && attributes.Length > 0) { Description = attributes[0].Description; } |
15 | else { Description = string.Empty; } |
16 | KeyValuePair<string, volumelevel=""> TypeKeyValue = |
17 | new KeyValuePair<string, VolumeLevel>(Description, level); |
18 | _VolumeLevelList.Add(TypeKeyValue); |
21 | return _VolumeLevelList; |
So now that you have your list and your enumeration, let’s insert the final piece. This will be the combobox in the xaml with bindings to your List. Note : The form I am using is a child of a maintenance view, so if your enum list is within the current datacontext, you won’t need the relative source binding.
4 | HorizontalAlignment="Left" |
6 | SelectedValuePath="Value" |
7 | ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type my:VolumeChangerMaintenanceView}}, Path=DataContext.VolumeLevelList}" |
8 | SelectedValue="{Binding SelectedVolumeLevel, ValidatesOnDataErrors=True, Mode=TwoWay}" |
There you go. All wired up and good to go. There are a few different ways to do this, but I thought I’d share mine just in case it helps somebody. Happy coding!
** UPDATE 11/16/2012 **
George had asked for a working example. I noticed an error in my code and is now fixed. Here is the working example!
**UPDATE 1/9/2014**
There was an issue with not calling the raise property changed from the public property, code has been updated and fixed
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Hi,
could you attach working example for this?
There is now a working example attached at the bottom of the post.
Wonderful! This is the first example that has worked for me. I’ve been on this issue for a few days now, and whoever designed ComboBox should be punished.