ListView - always checked one checkBox

Question

Mitja Bonca 557 Nearly a Posting Maven

16 Years Ago

I am doing some more coding on listView, and I can not figurate it out how to salve the problem that there is always just one checkBox on the listView checked.

On the listView I have some names. When I load it there is already a checked name - so far so good.

But I would like to do the code, that when I will check another checkBox, this one has to check and the other one which was checked before, it has to uncheck.
Anyone knows how to help me out with this?

So that there will always be just one checkBox checked.

.net:c# listview

4 Contributors
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Latest Post 13 Years Ago Latest Post by DjpjAmador

Dani AI

Generated 10 Months Ago

Short answer: treat the ListView checkboxes like radio buttons — when one item becomes checked, clear the others. As asked, that is the intended behaviour; and already showed the basic loop approach, and 's SelectionMode suggestion applies to WPF (System.Windows.Controls.ListView) rather than WinForms ListView.

A robust WinForms pattern is to temporarily unsubscribe the checked event while you change other items and wrap the changes in BeginUpdate/EndUpdate to avoid recursion and flicker. Example:

private void listView1_ItemChecked(object sender, ItemCheckedEventArgs e)
{
    if (!e.Item.Checked) return;

    listView1.ItemChecked -= listView1_ItemChecked; // prevent nested events
    try
    {
        listView1.BeginUpdate();
        foreach (ListViewItem it in listView1.Items)
            if (!object.ReferenceEquals(it, e.Item))
                it.Checked = false;
    }
    finally
    {
        listView1.EndUpdate();
        listView1.ItemChecked += listView1_ItemChecked;
    }
}

Notes and troubleshooting: if you must guarantee "exactly one" (user cannot uncheck the last item), handle uncheck attempts explicitly (re-check or select a default). If you are on WPF, prefer SelectionMode.Single or an ItemTemplate with RadioButtons. For virtual/owner-drawn ListViews manage check state yourself. Also confirm CheckBoxes is true and that the handler is wired on the UI thread to avoid invoke/locking issues.

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Mitja Bonca 557 Nearly a Posting Maven · Answer 1 · 2010-01-14T02:23:04+00:00

bool isChecking;
bool canCheck;
private void listView1_ItemCheck(object sender, ItemCheckEventArgs e)
{
    if (!isChecking && canCheck)
    {
        isChecking = true;
        foreach (ListViewItem item in listView1.Items)
        {
            item.Checked = false;
        }
        listView1.Items[e.Index].Checked = true;
        e.NewValue = CheckState.Checked;
        canCheck = false;
        isChecking = false;
    }
    else
    {
        if (isChecking)
        {
            e.NewValue = CheckState.Unchecked;
        }
        else
        {
            e.NewValue = e.CurrentValue;
        }
    }
}

private void listView1_MouseDoubleClick(object sender, MouseEventArgs e)
{
    // We can't unlock the lock if the value doesnt change.
    if (!listView1.GetItemAt(e.X, e.Y).Checked)
    {
        canCheck = true;
        listView1.GetItemAt(e.X, e.Y).Checked = true;
    }
}

Cxc8 0 Newbie Poster · Answer 2 · 2010-02-04T06:35:46+00:00

Here is another solution. Whenever a box is unchecked, there is no need to do anything. When the item that is checked is hit, we want to uncheck everything else.

private void lvMeets_ItemChecked(object sender, ItemCheckedEventArgs e)
        {
            if (!e.Item.Checked)
                return;

            foreach (ListViewItem item in lvMeets.Items)
            {
                if (item == e.Item)
                    continue;

                item.Checked = false;
            }
        }

Tarang 0 Newbie Poster · Answer 3 · 2010-12-22T13:24:00+00:00

private void listView1_ItemChecked(object sender, ItemCheckedEventArgs e)
        {
            foreach (ListViewItem lstItem in listView1.Items)
            {
                if (lstItem.Text != e.Item.Text)
                {
                    lstItem.Checked = false;
                }
            }
        }

DjpjAmador 0 Newbie Poster · Answer 4 · 2013-08-14T12:29:53+00:00

So many code...

listView1.SelectionMode = System.Windows.Controls.SelectionMode.Single;