Master Detail Detail with Business Objects (2 Questions) Win Forms

Question

I have a ListBox and 2 DataGridViews.

I have an Object which has

[Serializable]
public class Process
{
...
    public string ProcessName { get; set; }
    public List<Step> Steps { get; set; }
}

[Serializable]
public class Step
{
...
    public List<StepEvent> StepEvents { get; set; }
}

[Serializable]
public class StepEvent
{
...
    public int EventId { get; set; }
}

I can connect the listbox and the first grid, but I can not hook up the second grid. I don't think I can use a DataRelation because its an object not a DataTable

Code So Far

        List<Process> processes = new XMLHelper().CreateObject<List<Process>>(GetXmlProcess());

        listProcess.DataSource = processes;
        listProcess.DisplayMember = "ProcessName";
        listProcess.ValueMember = "ProcessName";

        dgSteps.DataSource = processes;
        dgSteps.DataMember = "Steps";


        //List<Step> steps = (from p in processes
        //                    from st in p.Steps
        //                    select st).ToList();

        dgStepEvents.DataSource = processes;
        dgStepEvents.DataMember = "Steps.StepEvents";

No matter what I make dgStepEvents.DataMember it gives me an error. As you can see I tried LINQ but then [steps] is a new object and doesn't link.

2nd related question: I have been reading a lot of BindableSource but I figured I didn't need something like that since the listview and the datagrid are already in sync.

Answer 1

You could do it the old fashion way of hooking up the SelectIndexChange Event

    private void listProcess_SelectedIndexChanged(object sender, EventArgs e)
    {
        Process p = listProcess.SelectedItem as Process;
        dgSteps.DataSource = p.Steps;

    }

    private void dgSteps_SelectionChanged(object sender, EventArgs e)
    {
        List<Step> steps = dgSteps.DataSource as List<Step>;

        dgStepEvents.DataSource = steps[dgSteps.CurrentRow.Index].StepEvents;

    }