combobox multiple valuemember single displaymember c#

Question

I have data like this...

id->name->floor
1->store1->1
2->store2->1
3->store2->2
4->store2->3
5->store3->2

I want add it in the combobox with display like this...

store1          
store2          
store3          

When I choose store2 I want get valuemember = 2, 3, 4

I think a logic (I'm not yet try at code)...
When I choose store2 I just get valuemember = 2 after that I check at database which id have same name in table. But I have 500++ data, so I think it's to waste process

Any idea??

note : this is just sample form, i don't know how to code, i just make design
it will be helpfull if you give me implementation to combobox not to cmd

Answer 1

Do you want to be easy to retrieve the data in selected items? I prefer to fill data with its special type so that can get data directly from seleted items. because the Combox.Item.Add() function needs a prameter in Object type, so, I suggest that you can firstly define your data in a new type, like this:

/// <summary>
/// my own data define
/// </summary>
public class MyFloor
{
    public int ID { get; set; }
    public string Name { get; set; }
    public string Floor { get; set; }

    //very important, the result will be displayed in the combox
    public override string ToString()
    {
        return string.Format("{0}->{1}->{2}", ID, Name, Floor);
    }
}

then, you can fill the data into combox in special type:

void FillData()
    {
        //load data from txt or database
        List<MyFloor> floorList = new List<MyFloor>(){
            new MyFloor{ID=1, Name="store1", Floor="1"},
            new MyFloor{ID=2, Name="store2", Floor="1"},
            new MyFloor{ID=3, Name="store2", Floor="2"},
            new MyFloor{ID=4, Name="store2", Floor="3"},
            new MyFloor{ID=5, Name="store3", Floor="2"}
            };
        //fill into combox
        foreach (MyFloor floor in floorList)
        {
            this.comboBox1.Items.Add(floor);
        }
    }

at last, you can get your data directly:

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        //retrieve data from selected item as MyFloor object
        MyFloor floor = this.comboBox1.SelectedItem as MyFloor;
        //show the selected data object
        if (floor != null)
        {
            txtID.Text = floor.ID.ToString();
            txtName.Text = floor.Name;
            txtFloor.Text = floor.Floor;
        }
    }

here is my result: