entity.MetaFuncs.MEStringsSelector.textBox1_KeyDown C# (CSharp) Method

        private void textBox1_KeyDown(object sender, KeyEventArgs e)
        {
            int listHeight = lbStringIDs.Height / lbStringIDs.ItemHeight;
            switch (e.KeyCode)
            {
                /*
                case Keys.Home:
                    if (lbStringIDs.Items.Count > 0)
                    {
                        lbStringIDs.SelectedIndex = 0;
                    }
                    break;

                case Keys.End:

                    // if (listBox1.Items.Count > 0)
                    lbStringIDs.SelectedIndex = lbStringIDs.Items.Count - 1;
                    break;
                */
                case Keys.PageUp:
                    if (lbStringIDs.Items.Count > 0)
                    {
                        if (lbStringIDs.SelectedIndex > listHeight)
                        {
                            lbStringIDs.SelectedIndex -= listHeight;
                        }
                        else
                        {
                            lbStringIDs.SelectedIndex = 0;
                        }
                    }

                    break;
                case Keys.Up:
                    if (lbStringIDs.SelectedIndex > 0)
                    {
                        lbStringIDs.SelectedIndex -= 1;
                    }

                    break;
                case Keys.Down:

                    // if (listBox1.Items.Count > 0)
                    if (lbStringIDs.SelectedIndex < lbStringIDs.Items.Count - 1)
                    {
                        lbStringIDs.SelectedIndex += 1;
                    }

                    break;
                case Keys.PageDown:

                    // if (listBox1.Items.Count > 0)
                    if (lbStringIDs.SelectedIndex + listHeight < lbStringIDs.Items.Count - 1)
                    {
                        lbStringIDs.SelectedIndex += listHeight;
                    }
                    else
                    {
                        lbStringIDs.SelectedIndex = lbStringIDs.Items.Count - 1;
                    }

                    break;
                case Keys.Enter:
                    listBox1_DoubleClick(sender, new EventArgs());
                    break;
            }
        }