Changing Combobox item in code-behind throws invalidoperationexception

Question

I have several comboboxes which are initialiced with a default text which will be replaced later on by textes out of a text-file to support different languages. I tried different ways to change the text but none of them worked out:

Initialization:

myCombobox.itemSource = new ObservableCollection(Of String){"FirstItem", "SecoundItem"})

First Way:

myCombobox.Items(i) = GetString(myCombobox.Items(i))

Secound Way:

Dim comboboxStr = myCombobox.Items(i)
myCombobox.Items.RemoveAt(i)
myCombobox.Items.Add(GetString(i))

Both ways throw an InvalidOperationException with the hint to try "ItemsControl.ItemsSource" instead of "ItemsSource"

Is there maybe another way to change the items or what why is this exception occurring?

score 1 · Accepted Answer · answered Aug 11 '14 at 07:49

This is a common problem. Once you have data bound the ItemsControl.ItemsSource (or any class derived from ItemsControl, then you cannot use the ItemsControl.Items property to manipulate the data. Instead, (you should declare a property and) just access the data collection that you data bound directly:

SomeProperty = new ObservableCollection(Of String){"FirstItem", "SecoundItem"})

...

myCombobox.itemSource = SomeProperty

...

SomeProperty.Remove(someItem)

Changing Combobox item in code-behind throws invalidoperationexception

1 Answers1