小编Ray*_*ark的帖子

可能重复:
.NET中是否有字符串数学计算器？

有没有办法转换操作员代码而不进行检查"+", "-", "*", "/"然后传递值？

using System;

namespace ConsoleApplication1
{
    class Program
    {
        private static void Main(string[] args)
        {
            string operator = "+";
            int inputOne = 2;
            int inputTwo = 5;

            Console.WriteLine(Result(inputOne, inputTwo, operator));
            Console.ReadLine();
        }


        public static string Result(int one, int two, string computeOperator)
        {
            if (computeOperator == "+")
            {
                return (one + two).ToString();
            }

            if (computeOperator == "-")
            {
                return (one - two).ToString();
            }

            //and so on...

            return "0";
        }
    }
}

我尝试了多种组合，但无法清除此控件。我正在使用 jquery 3.2.1，控件是 Bootstrap-select v1.13.1 这里是链接 https://developer.snapappointments.com/bootstrap-select/。

我想清除 teamPositionFilter 选项，每当 groupFilter 更改之前，该选项都是多选的。现在它在每次更改后附加值。我可以单步执行 javascript 代码，但它不会更改列表。

@Html.DropDownList("groupFilter", (SelectList)(@ViewBag.GroupList), new { @class = "singleselectpicker col-md-3", title = "Group:", data_header = "Select Group:" })
@Html.DropDownList("teamPositionFilter", (MultiSelectList)(@ViewBag.TeamPositionList), new { @class = "multiselectpicker col-md-3", multiple = "multiple", title = "Team Position:", data_header = "Select one or more Team Positions:" })

$(function() {

$('#groupFilter').change(function () {
    var #teamPositionFilter = $('#teamPositionFilter');
    #teamPositionFilter.find('option').remove();
    #teamPositionFilter.selectpicker('refresh');
});


$('.singleselectpicker').selectpicker({
    showTick: true,
    tickIcon: 'glyphicon-pushpin',
    liveSearch: true,
    liveSearchStyle: 'contains',
    selectOnTab: true,
    showContent: true, …