Collection was modified; enumeration operation may not execute.

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Hi,

I have a list box there is 5 data.i want to remove data from listbox but when i am clik on botton
then getting error
Collection was modified; enumeration operation may not execute.

my Coding is

C#

foreach (ListItem selectItem in lstSelectPages.Items)
{
    if (selectItem.Selected == true)
    {
        lstSelectPages.Items.Remove(lstSelectPages.SelectedItem);
        lstSelectPages.DataBind();      
    }
}

please help me out

Posted 9-Aug-13 20:13pm

Pradhan Gagan

Updated 18-Aug-21 3:41am

Dennis C. Dietrich

v3

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2 solutions

Solution 1

Foreach does not allow the manupulation of the collection. Try for loop as shown.

C#

for(int x=0; x < lstSelectPages.Items.Count;x++)
            {
                if (lstSelectPages.SelectedItem == lstSelectPages.Items[x])
                {
                    lstSelectPages.Items.RemoveAt(x);
                    lstSelectPages.DataBind();
                }
            }

Posted 9-Aug-13 21:37pm

ArunRajendra

Comments

Pradhan Gagan 10-Aug-13 3:48am

THANKS LOT I GOT RAGING SOLUTION FROM ONLY YOUR SIDE

ArunRajendra 10-Aug-13 4:56am

Can you mark the solution as answered. :)

ArunRajendra 10-Aug-13 4:55am

welcome :)

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Bernhard Hiller · Accepted Answer · 2013-08-11T21:58:00

Solution 2

The loop is not needed at all:

SQL

if (lstSelectPages.SelectedItem != null)
{
    lstSelectPages.Items.Remove(lstSelectPages.SelectedItem);
    lstSelectPages.DataBind();
}

Posted 11-Aug-13 21:58pm

Bernhard Hiller

Comments

Maciej Los 12-Aug-13 4:35am

+5!