/// <summary>
/// Extends BeginInvoke so that when a state object is not needed, null does not need to be passed.
/// <example>
/// toolstripdropdownclosingeventhandler.BeginInvoke(sender, e, callback);
/// </example>
/// </summary>
public static IAsyncResult BeginInvoke(this ToolStripDropDownClosingEventHandler toolstripdropdownclosingeventhandler, Object sender, ToolStripDropDownClosingEventArgs e, AsyncCallback callback)
{
if (toolstripdropdownclosingeventhandler == null)
{
throw new ArgumentNullException("toolstripdropdownclosingeventhandler");
}
return(toolstripdropdownclosingeventhandler.BeginInvoke(sender, e, callback, null));
}
protected virtual void OnClosing(ToolStripDropDownClosingEventArgs e)
{
ToolStripDropDownClosingEventHandler eh = (ToolStripDropDownClosingEventHandler)(Events [ClosingEvent]);
if (eh != null)
{
eh(this, e);
}
}
public static void ShowMultiSelectMenu <T>(Point position, IEnumerable <Tuple <T, bool> > items, Action <List <T> > pickHandler)
{
List <Tuple <T, bool> > itemList = items?.OrderBy(item => item.Item1.ToString()).ToList();
if (itemList == null || !itemList.Any())
{
return;
}
bool anyItemClicked = false;
ContextMenuStrip contextMenu = new ContextMenuStrip();
ToolStripDropDownClosedEventHandler contextMenuClosedEventHandler = null;
ToolStripDropDownClosingEventHandler contextMenuClosingEventHandler = null;
ToolStripItemClickedEventHandler menuItemClickedEventHandler = null;
contextMenuClosedEventHandler = (sender, e) =>
{
contextMenu.Closed -= contextMenuClosedEventHandler;
contextMenu.Closing -= contextMenuClosingEventHandler;
contextMenu.ItemClicked -= menuItemClickedEventHandler;
};
contextMenuClosingEventHandler = (sender, e) =>
{
if (e.CloseReason == ToolStripDropDownCloseReason.ItemClicked)
{
e.Cancel = true;
((ToolStripDropDownMenu)sender).Invalidate();
}
else if (anyItemClicked)
{
List <T> selectedItems = ((ToolStripDropDownMenu)sender).Items.Cast <ToolStripMenuItem>().Where(x => x.Checked).Select(x => (T)x.Tag).ToList();
pickHandler(selectedItems);
}
};
menuItemClickedEventHandler = (sender, e) =>
{
ToolStripMenuItem clickedItem = (ToolStripMenuItem)e.ClickedItem;
clickedItem.Checked = !clickedItem.Checked;
anyItemClicked = true;
};
contextMenu.Closed += contextMenuClosedEventHandler;
contextMenu.Closing += contextMenuClosingEventHandler;
contextMenu.ItemClicked += menuItemClickedEventHandler;
itemList.ForEach(item => contextMenu.Items.Add(new ToolStripMenuItem(item.Item1.ToString())
{
Tag = item.Item1, Checked = item.Item2
}));
contextMenu.Show(position);
}
