自定义底部菜单：

使用方法：

@objc fileprivate func onAlertAction(sender: UIButton) {    let items = [AlertSheetItem(title: "退出", style: .special), AlertSheetItem(title: "其他", style: .light)]    let sheet = AlertSheet.actionSheet(title: "请选择", cancelItemTitle: "取消", otherItemTitles: items)    sheet.didClickedItemAtIndexHandler = { (rowIndex) in        if rowIndex == 0 {            NSLog("didClicked Item at \(rowIndex)")        }    }    sheet.didClickedCancelHandler = {        NSLog("didClicked Cancel")    }    sheet.show()}

运行效果：

支持多个item的列表显示：