使用实体框架在WPF中的数据网格中显示子记录

Question

I have two tables named Process and ProcessTriggers . ProcessTriggers referring Process table.And need to create a screen to diplay Process as well as the ProcessTrigger related to the Process. I have created data objects using entity framework and my classes look like.

public partial class Process
    {  
       public Process()
        {
            this.ProcessTriggers = new ObservableCollection<ProcessTrigger>();
        }

        public int ID { get; set; }
        public int WorkflowID { get; set; }
        public string Name { get; set; }
        public bool IsBatch { get; set; }
        public Nullable<System.DateTime> ModifiedOn { get; set; }

        public virtual ObservableCollection<ProcessTrigger> ProcessTriggers { get; set; }
}

And my view model look like..

public class ProcessViewModel : ViewModel<Process>
{
    private RelayCommand saveCommand;
    private RelayCommand cancelCommand;

    public ProcessViewModel()
    {
        using(var context = new PACEContext())
        {
            this.Entity = context.Processes.FirstOrDefault(i => i.ID == 1);
            IsInEditMode = true;
        }
    }
 }

I am binding these viewModel to my View, Entity properties are bound correctly, but the ProcessTriggerCollection is not binding to datagrid ..

<DataGrid ItemsSource="{Binding Entity.ProcessTriggers}" AutoGenerateColumns="True">
                    </DataGrid>

I juts started learning WPF, MVVM and Entity framework.Can any one help.?

Answer 1

I understand the Process have a ObservableCollection of other class called ProcessTriggers.

Why you don't create a ObservableCollection and binding this?

private ObservableCollection<ProcessTrigger> _listProcessTriggers;
    public ObservableCollection<ProcessTrigger> ListProcessTriggers
    {
        get { return _listProcessTriggers; }
        set { _listProcessTriggers= value; RaisePropertyChanged("ListProcessTriggers"); }
    }

public ProcessViewModel()
{
    using(var context = new PACEContext())
    {
        this.Entity = context.Processes.FirstOrDefault(i => i.ID == 1);
        ListProcessTriggers = Entity.ProcessTriggers;
        IsInEditMode = true;
    }
}

And In Xmal Binding

<DataGrid ItemsSource="{Binding ListProcessTriggers}" AutoGenerateColumns="True />