How to set multiple selected items on a WinForms ListBox

Question

I have a System.Windows.Forms.ListBox in multiple selection mode and a set of items I'd like to be selected. How do I do that?

[Test]
public void SetListBox()
{
    var listBox = new ListBox();
    var items = new List<string>{"one", "two", "three", "four"};
    listBox.SelectionMode = SelectionMode.MultiSimple;
    listBox.Items.AddRange(items.ToArray());
    var selectedItems = new List<string> {"two", "four"};
    // ???
    Assert.AreEqual(selectedItems, listBox.SelectedItems);
}

Answer 1

Do this:

selectedItems.Select(sd => listBox.Items.IndexOf(sd)).Where(i => i >= 0).ToList().ForEach(i => listBox.SetSelected(i, true));

For:

    [Test]
    public void SetListBox()
    {
        var listBox = new ListBox();
        var items = new List<string>{"one", "two", "three", "four"};
        listBox.SelectionMode = SelectionMode.MultiSimple;
        listBox.Items.AddRange(items.ToArray());

        var selectedItems = new List<string> {"two", "four"};
        selectedItems.Select(sd => listBox.Items.IndexOf(sd)).Where(i => i >= 0).ToList().ForEach(i => listBox.SetSelected(i, true));

        Assert.AreEqual(selectedItems, listBox.SelectedItems);
    }