I have set the ItemsSource of my combobox column to a list of custom objects. This works fine and I am able to update my object with the selected item from the combobox. The problem is that my users will need to be able to set this column to null, so I add a null to the list of objects. I can see the null in the list fine, but whenever I select it, the property of the DataMember SalesRep does NOT get set at all. I have to select a different item in the list. I've put a break point on the Property set and it isn't firing at all on null. Is this a bug, or is there a "better" way?
...
<DataTemplate DataType="{x:Type lib:Security.UserInfo}">...
<TextBlock>
<TextBlock.Text>
<MultiBinding StringFormat="{}{0}, {1}">
<Binding Path="LastName" />
<Binding Path="FirstName" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
</DataTemplate>
<telerik1:GridViewComboBoxColumn Name="SalesRepColumn" Header="Sales Rep" DataMemberBinding="{Binding SalesRep, ValidatesOnDataErrors=True,ValidatesOnExceptions=True,UpdateSourceTrigger=PropertyChanged}"/>...
CollectionViewSource userInfoSource = this.FindResource("userInfoSource") as CollectionViewSource;
var ul = UserInfoList.GetUserInfoList().OrderBy(u => u.LastName).ToList();
ul.Insert(0, null);
userInfoSource.Source = ul;
SalesRepColumn.ItemsSource = userInfoSource.View;
...
public UserInfo SalesRep {
get { return GetProperty(SalesRepProperty); }
set { _salesRep = value; }
}