/// <summary>
/// Invoked when the selected index is changed on the dropdown. This sets the check state
/// of the CheckComboBoxItem and fires the public event CheckStateChanged using the
/// CheckComboBoxItem as the event sender.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void CheckComboBox_SelectedIndexChanged(object sender, EventArgs e)
{
CheckComboBoxItem item = (CheckComboBoxItem)SelectedItem;
item.CheckState = !item.CheckState;
if (CheckStateChanged != null)
{
CheckStateChanged(item, e);
}
}
/// <summary>
/// Invoked when the ComboBox has to render the drop-down items.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
void CheckComboBox_DrawItem(object sender, DrawItemEventArgs e)
{
// make sure the index is valid (sanity check)
//--------------------------------------------------------------------
if (e.Index == -1)
{
return;
}
// test the item to see if its a CheckComboBoxItem
//---------------------------------------------------------------
if (!(Items[e.Index] is CheckComboBoxItem))
{
// it's not, so just render it as a default string
e.Graphics.DrawString(
Items[e.Index].ToString(),
this.Font,
Brushes.Black,
new Point(e.Bounds.X, e.Bounds.Y));
return;
}
// get the CheckComboBoxItem from the collection
//---------------------------------------------------------------------
CheckComboBoxItem box = (CheckComboBoxItem)Items[e.Index];
// render it
CheckBoxRenderer.DrawCheckBox(
e.Graphics,
new Point(e.Bounds.X, e.Bounds.Y),
new Rectangle(new Point(e.Bounds.X + 13, e.Bounds.Y), new Size(e.Bounds.Width, e.Bounds.Height)),
box.Text,
this.Font,
TextFormatFlags.Left,
(e.State & DrawItemState.Focus) == 0,
box.CheckState ? CheckBoxState.CheckedNormal : CheckBoxState.UncheckedNormal);
}