How can I get the string value of a checked item from a CheckedListBox?

Question

I've got this code to try to extract the display value from a CheckedListBox:

CheckedListBox.CheckedItemCollection selectedUnits = checkedListBoxUnits.CheckedItems;
_selectedUnit = selectedUnits[0].ToString();

...but it doesn't work - the value of "_selectedUnit", instead of being "platypus" as it should be, is "System.Data.DataRowView".

How can I coax the string value out of this complex object?

UPDATE

I'm not sure just what user2946329 wants to see bzg. my CheckedListBox, but here is how it is populated:

private void PopulateUnits()
{
    using (SqlConnection con = new SqlConnection(ReportRunnerConstsAndUtils.CPSConnStr))
    {
        using (SqlCommand cmd = new SqlCommand(ReportRunnerConstsAndUtils.SelectUnitsQuery, con))
        {
            cmd.CommandType = CommandType.Text;
            using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
            {
                DataTable dt = new DataTable();
                sda.Fill(dt);
                ((ListBox)checkedListBoxUnits).DataSource = dt;
                ((ListBox)checkedListBoxUnits).DisplayMember = "Unit";
                ((ListBox)checkedListBoxUnits).ValueMember = "Unit";
            }
        }
    }
}

Let me know if there is anything missing that would help you.

I believe you want to access the Item within selectedUnits[0] and call ToString() on that, not the container itself — wentimo, Dec 22 '15 at 19:08
Take a look here https://msdn.microsoft.com/en-us/library/system.windows.forms.checkedlistbox.checkeditems(v=vs.110).aspx — ProgrammerV5, Dec 22 '15 at 19:08
@wentimo: Okay, but how do I do that ("access the item within the selectedUnits[0]"? The only thing available after a "." appended to that is ToString() - there is no "DisplayValue" or such. — B. Clay Shannon-B. Crow Raven, Dec 22 '15 at 19:38
@ProgrammerV5: I don't see anything at that link that helps me; the best I could derive from there was "object itemChecked = selectedUnits[0].ToString();" and that also is "System.Data.DataRow.View" — B. Clay Shannon-B. Crow Raven, Dec 22 '15 at 19:46
@B.ClayShannon...I think it will be better to rollback to previous version of your post for more readability. I thought showing `CheckedListBox` would help that moment! — Salah Akbari, Dec 22 '15 at 20:28
@user2946329: Leaving it as-is gives answers to people in both situations. — B. Clay Shannon-B. Crow Raven, Dec 22 '15 at 21:07

score 2 · Accepted Answer · edited Dec 22 '15 at 21:32

2

It should be something like this:

DataRowView dr = checkedListBoxUnits.CheckedItems[0] as DataRowView;
string Name = dr["Unit"].ToString();

edited Dec 22 '15 at 21:32

B. Clay Shannon-B. Crow Raven

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answered Dec 22 '15 at 19:13

Salah Akbari

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score 1 · Answer 2 · answered Dec 22 '15 at 19:49

Judging by the string you get ("System.Data.DataRowView"), you use the CheckListBox with datasource attached. If that's the case, in CheckedItems you really get DataRowViews.. hence the string, since its ToString() returns class name. You will need to access the data from the DataRowView, by column name or index.

score 1 · Answer 3 · answered Dec 22 '15 at 19:55

1

_selectedUnit = ((DataRowView)selectedUnits[0])["Name"].ToString();

the key is to typecast the item before accessing it...

answered Dec 22 '15 at 19:55

MaxOvrdrv

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score 0 · Answer 4 · answered Dec 22 '15 at 23:32

0

Combining user2946329's answer with Resharper's contribution, the code I ended up using is:

String _selectedUnit;
. . .
DataRowView dr = checkedListBoxUnits.CheckedItems[0] as DataRowView;
if (dr != null) _selectedUnit = dr["Unit"].ToString();

(Resharper complained about a possible null reference issue, and so added the "if (dr != null)" jazz to the last line.

answered Dec 22 '15 at 23:32

B. Clay Shannon-B. Crow Raven

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You could also get OutOfRange exception if there are none items checked in the list, since you directly access item at index 0 without any check whether or not there is such item. – Jiri P. Dec 22 '15 at 23:41
Yes, theoretically it's not possible, because the "Go" button is disabled until a unit has been selected (among other things), but I know it's better to be defensive than offensive when it comes to programming. – B. Clay Shannon-B. Crow Raven Dec 22 '15 at 23:45

How can I get the string value of a checked item from a CheckedListBox?

UPDATE

4 Answers4

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