CODEWITHSUNDEEP
winformsforeachcheckedlistbox
topofsteel
topofsteel

Reputation: 1277

iterate through checkedListBox testing for checked - cast error

i'm trying to check each item in a checkedlistbox and do something with the item depending if it is checked or not. I've been able to just get the checked items with the indexCollection, but i'm having trouble getting all of the items, i'm getting this error 'Unable to cast object of type 'System.String' to type 'System.Windows.Forms.ListViewItem'

        foreach (ListViewItem item in checkedListBox2.Items)
        {
            if (item.Checked == true)
                //do something with item.name

            else
                //do something else with item.name
        }

i'm unsure why it's giving me the string cast error in the foreach line. How can I accomplish this? Thanks.

Upvotes: 7

Views: 17346

Answers (2)

Steve
Steve

Reputation: 216313

If you allow a checkbox to have the Indeterminate state then you should use the GetItemCheckState method to retrieve the state of a check box 

for (int i = 0; i < checkedListBox2.Items.Count; i++) 
{
     CheckState st = checkedListBox2.GetItemCheckState(checkedListBox2.Items.IndexOf(i));
     if(st == CheckState.Checked)
        ....
     else if(st == CheckState.Unchecked)
        ....
     else
        ... // inderminate
}

otherwise is enough to call GetItemChecked that return a true/false value (true also for the indeterminate state)

Upvotes: 7

VladL
VladL

Reputation: 13043

CheckedListBox.Items holds the collection of objects, not the collection of ListViewItem

You can check it this way

        for (int i = 0; i < checkedListBox2.Items.Count; i++)
        {
            if (checkedListBox2.GetItemChecked(i))
            {
                //do something with checkedListBox2.Items[i]
            }
            else
            {
                //do something else with checkedListBox2.Items[i]
            }
        }

Upvotes: 2

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