Adding Items From A List<ListViewItem>

Question

Sorry for my bad English :(.

Hi, how do I add the items to a ListView that I've put in a List?

I've tried this:

listView1.Items.Add(pluginContainer);

But this doesn't seem to work :(.

I can't make a foreach loop because then it will take like 10 seconds for the ListView to be filled (I'm talking about 5000+ items).

This fixed it:

listView1.Items.AddRange(pluginContainer.ToArray());

Answer 1

Try this:

public enum State
{
    AL, GA, FL, SC, TN, MI
}

public class Person
{
    public int ID { get; set; }
    public string Name { get; set; }
    public State State { get; set; }
    // Converts properties to string array
    public string[] ToListViewItem()
    {
        return new string[] {
            ID.ToString("00000"),
            Name,
            State.ToString() };
    }
}

public partial class Form1 : Form
{

    public Form1()
    {
        InitializeComponent();
        //Setup list view column headings and widths
        listView1.Columns.Add("ID", 48);
        listView1.Columns.Add("Name", 300);
        listView1.Columns.Add("State", 48);
    }

    protected override void OnLoad(EventArgs e)
    {
        base.OnLoad(e);

        // Create a list
        List<Person> list = new List<Person>();
        // Fill in some data
        list.Add(new Person() { ID=1001, Name="John", State=State.TN });
        list.Add(new Person() { ID=1002, Name="Roger", State=State.AL });
        list.Add(new Person() { ID=1003, Name="Samantha", State=State.FL});
        list.Add(new Person() { ID=1004, Name="Kara", State=State.MI});

        // Fill in ListView from list
        PopulateListView(list);
    }

    void PopulateListView(List<Person> list)
    {
        listView1.SuspendLayout();
        for(int i=0; i<list.Count; i++)
        {
            // create a list view item
            var lvi = new ListViewItem(list[i].ToListViewItem());
            // assign class reference to lvi Tag for later use
            lvi.Tag = list[i];
            // add to list view
            listView1.Items.Add(lvi);
        }
        //This adjust the width of 1st column to fit data.
        listView1.AutoResizeColumn(0, ColumnHeaderAutoResizeStyle.ColumnContent);
        listView1.ResumeLayout();
    }
}

Answer 2

If the items in your list are all of type ListViewItem, you can use AddRange. If they're not, you're going to have to either make ListViewItems out of them, or use a for loop.

In either case, you should strive to improve the performance of a ListView during addition of items, by first calling SuspendLayout on it. After you've added all its items, call ResumeLayout.