Putting in ValueMember and getting ValueMember out of Listbox

Question

Hello everyone out there! I'm trying to define the Valuemember and the Datasource of a Listbox Called "lb_Kostenstellen" (I need the ID of the Items for updating the Item in my Database) with the following statement:

lb_Kostenstellen.DataSource = db.Kostenstellen.ToList();
lb_Kostenstellen.ValueMember = "ID";
lb_Kostenstellen.DisplayMember = "Kostenstelle";

Now i created a button called "bt_Hinzufügen". When i click on the button, the Selected Item should move from my listbox called "lb_Kostenstellen" to "lb_Ausgewählt". (The item should be not visible in the first Listbox). I use this statement:

lb_Ausgewählt.Items.Add(lb_Kostenstellen.SelectedItem);

Until now, the statement works.

But now my Question: If i "switch" 3 Items from one Listbox to the Other,and then clicking on a button, I want to display 3 Messageboxes with the ID of every unique Item.

It doesn't work. I only get in the Messageboxes that:

1. MB : I
2. MB : D

3. MB : (NOTHING)

   for (int i = 0; i < lb_Ausgewählt.Items.Count; i++) { MessageBox.Show(lb_Ausgewählt.ValueMember[i].ToString()); }

I hope you have a compatible solution for me. Thanks, Daniel

My DatabaseContext is "db" (For EntityFramework).

Answer 1

You are iterating through the string "ID" as lb_Chosen.ValueMember is a string with value "ID".

You should use something like the code below to get your IDs:

for (int i = 0; i < lb_Chosen.Items.Count; i++) 
{ 
   MessageBox.Show((lb_Chosen.Items[i] as YourAccountClass).ID.ToString()); 
}

Edit: translated names in code to english