Question

using Entity Framework (C#) I have a User class which has ONE:MANY mapping to the UserRight class (simply, user has a set of rights). Each right is identified by a string. And now, because the maximum number of possible rights is finite (<10) I’d like to have 10 CheckBoxes and edit the subset of rights for a given user manually.

What is the nice way to do it?

James

Answer 1

Create a RightViewModel class to contain user rights:

public class RightViewModel : INotifyPropertyChanged
{
    private string _name;
    public string Name
    {
        get { return _name; }
        set
        {
            _name = value;
            Change("Name");
        }
    }

    private bool _hasRight;
    public bool HasRight
    {
        get { return _hasRight; }
        set
        {
            _hasRight = value;
            Change("HasRight");
        }
    }

    public void Change(string strPropertyName)
    {
        if (PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs(strPropertyName));
    }
    public event PropertyChangedEventHandler PropertyChanged;
}

Create a similar class for your user, containing a member Rightsof type ObservableCollection<RightViewModel>.

In you XAML, use an ItemsControl:

<ItemsControl ItemsSource="{Binding Rights}"
    ItemTemplate="{StaticResource RightTemplate}"/>

And a template definition:

<DataTemplate x:Key="RightTemplate">
    <CheckBox Content="{Binding Name}" IsChecked="{Binding HasRight, Mode=TwoWay}"/>
</DataTemplate>

Mode=TwoWay makes the binding update your RightViewModel instance.

Define the ItemsControl‘s ItemsPanel if you need to display your checkboxes with a different layout.

Finally set your user as the DataContext of your container.