[RESOLVED] multiple items in a listbox

[Triumph]

I am trying to remove multiple selected items in a listbox, this code isnt working:

private void btnRemove_Click(object sender, System.EventArgs e)
{
	for (int x = 0; x < lstFiles.Items.Count; x++)
	{
		if (lstFiles.SelectedIndices.Contains(x))
		{
			lstFiles.Items.RemoveAt(x);
		}
	}
}

Not all selected items get removed, but most of them do.
edit: seems its the first thing selected that doesnt get removed.

[deranged]

Try this:

private void btnRemove_Click(object sender, System.EventArgs e)
{
	for (int x = 0; x != lstFiles.Items.Count; x++)
	{
		if (lstFiles.SelectedIndices.Contains(x))
		{
			lstFiles.Items.RemoveAt(x);
		}
	}
}

[Triumph]

i tried that, and it has the same exact problem, first selected item doesnt get removed.

[jmcilhinney]

If you want to remove multiple items from a collection then you should start from the end and work backwards so that each item you remove does not affect the remaining indices:

private void btnRemove_Click(object sender, System.EventArgs e)
{
	for (int x = lstFiles.Items.Count - 1; x >= 0; lstFiles.Items.Count; x--)
	{
		if (lstFiles.SelectedIndices.Contains(x))
		{
			lstFiles.Items.RemoveAt(x);
		}
	}
}

but in this case you could actually do this:

while (this.listBox1.SelectedItems.Count > 0)
{
    this.listBox1.Items.Remove(this.listBox1.SelectedItems[0]);
}

or this:

for (int i = this.listBox1.SelectedItems.Count - 1; i >= 0; i--)
{
    this.listBox1.Items.Remove(this.listBox1.SelectedItems[i]);
}

[Triumph]

Thanks alot. That fixed it. I understand now why it wasnt removing the right items, I never considered the fact that the indices changed as things got removed.