CODEWITHSUNDEEP
c#classlistviewlistviewitem
Victor Lev
Victor Lev

Reputation: 1

ListView problems, Cross class operation

I'm trying to add an ListViewItem to a listView on the main form (Form1), from another class(Comm).

Form1:

    public ListViewItem lvi_tmp;

    private void Form1_Load(object sender, EventArgs e)
    {
        comm = new Comm(this);
    }
    public void add_to_reg(ListViewItem tmp)
    {
        lvi_tmp = tmp;
        this.Invoke(new EventHandler(add_to_reg_event));
    }

    public void add_to_reg_event(Object sender, EventArgs e)
    {
        lst_reg.Items.Add(lvi_tmp);
        lst_reg.Refresh();
        this.Refresh();
    }

Comm:

    public Form1 mainFrm { get; set; }

    public Comm (Form1 _form1)
    {
        mainFrm = _form1;
    }

    private void Add_item()
    {
        lvi = new ListViewItem("itemTest");
        lvi.SubItems.Add("subitemTest");
        lvi.Tag = 1;

        mainFrm.add_to_reg(lvi);
    }

This code throwing the next Exception:

"Invoke or BeginInvoke cannot be called on a control until the window handle has been created."

Any ideas?

Upvotes: 0

Views: 38

Answers (1)

Matthew Watson
Matthew Watson

Reputation: 109567

You can check InvokeRequired before callling BeginInvoke(). Perhaps this will work for you:

public void add_to_reg(ListViewItem tmp)
{
    lvi_tmp = tmp;

    if (this.InvokeRequired))
        this.Invoke(new EventHandler(add_to_reg_event));
    else
        add_to_reg_event(null, null);
}

Although I'd split up add_to_reg_event() and use a lambda to avoid that temporary variable:

public void add_to_reg(ListViewItem tmp)
{
    if (this.InvokeRequired))
        this.Invoke(new Action(() => add_to_reg_impl(tmp)));
    else
        add_to_reg_impl(tmp);
}

private void add_to_reg_impl(ListViewItem item)
{
    lst_reg.Items.Add(item);
    lst_reg.Refresh();
    this.Refresh();
}

Upvotes: 1

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