Binding Ischecked of a checkbox in wpf listbox on selectionchanged of the combobox

Question

I have a combobox of customer and that customer can be in more than 1 categories so i used a listbox which contains check-boxes of all the categories...

On the selection change of the customer, the categories in which a particular customer is, should be checked and all the other categories should remain unchecked..

here is my .dbml file

Here is my xaml code of listbox...

  <ListBox Height="113.88" Margin="399.342,125.543,424.66,0" Name="lst_category" VerticalAlignment="Top" SelectedValuePath="CategoryID">
            <ListBox.ItemTemplate>
                <HierarchicalDataTemplate>
                <CheckBox Content="{Binding CategoryName}"/>
            </HierarchicalDataTemplate></ListBox.ItemTemplate>
        </ListBox>

I think i should use relative source in the binding in Ischecked property of checkbox... But i dont know how to use it please help me out... If there is some other solution to this than do let me know.. Thanks in advance...

Answer 1

Solution 1: Create a class CategoryViewModel like this:

class CategoryViewModel : INotifyPropertyChanged
{
   public Category Category {get ... set ...}
   public bool IsChecked {get ... set ...} //true if Category belongs to currently selected contact
}

Bind your UI to a ViewModel class that contains a list of CategoryViewModel that gets computed whenever you change the Selected Contact.

Basically:

class ViewModel : INotifyPropertyChanged
{
   public Contact SelectedContact { get .... set ....}

   //list of all possible categories (the ones belonging to SelectedContact will have IsChecked true
   public ObservableCollection<CategoryViewModel> Categories 
   {
       get .... set ....
   }   
}

Bind your listbox above to ViewModel.Categories property.

SelectedContact should be bound to the currently selected contact. When it changes, in the setter, you re-create Categories list.

Solution 2: Use some converters (wouldn't recommend it thought, because it's not MVVM)