private void calendar1_ScheduleLabelMouseUp(object sender, CalendarControl.Calendar.ScheduleLabelMouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Right)
{
var menuitems = new ToolStripMenuItem[4];
menuitems[0] = new ToolStripMenuItem("削除", null, MenuDeleteClick);
menuitems[1] = new ToolStripMenuItem("その他の候補者", null, MenuOtherClick);
menuitems[2] = new ToolStripMenuItem("ランダム選択", null, MenuRandomSelect);
menuitems[3] = new ToolStripMenuItem("フリー入力", null, MenuFreeCommentClick);
menuitems[0].ShortcutKeyDisplayString = "Delete";
menuitems[2].ShortcutKeyDisplayString = "Ctrl+R";
menu.Items.Clear();
menuitems.ToList().ForEach(t => menu.Items.Add(t));
this.ContextMenuStrip = menu;
this.ContextMenuStrip.Show(PointToScreen(new Point(e.X, e.Y)));
}
}