索引超出范围。插入列表时必须为非负数

Question

我有一个简单的网格，标题内有几个文本框，我想用它们来过滤网格。 为此，我创建了一个函数，该函数将创建或更新cookie，我需要将cookie存储/保存在某个地方。我希望过滤器在刷新页面后仍保留在那里。

因此，当用户填写文本框并按Enter时，将执行以下代码：

...
       model.FilteringValue = new List<FilterValues>();
   //fill cookies
            foreach (var filter in columnsFilter)
            {
                var filtercolumn = filter.Key.ToString() + "filter";

                //Checken if cookie exists
                if (Request.Cookies[filtercolumn] != null)
                {
                    //Cookie does exists. proceed
                    //Check if value has a value.
                    if(filter.Value != "")
                    {
                        //Filter has a value, update the cookie
                        Response.Cookies[filtercolumn].Value = filter.Value.ToString();

                    }
                    else
                    {
                        //Filter.value is empty. which means the user has removed the input textbox's value and we should now delete or empty the cookie
                        Response.Cookies[filtercolumn].Value = filter.Value.ToString();
                    }
                }
                else
                {
                    //Cookie create.
                    //check if filter has value
                    if (filter.Value != "")
                    {
                        SetCookies(filter.Key + "filter", filter.Value.ToString());
                    }
                    else
                    {
                        SetCookies(filter.Key + "filter", "");

                    }
                }

                //Set cookie value to the model we use for the view.
                model.ColumnsFilter[filter.Key] = Request.Cookies[filtercolumn].Value.ToString();

            }
            for (int i = 0; i < model.ColumnsFilter.Count; i++)
            {
                foreach(var item in model.ColumnsFilter)
                {
                    //Fill list with ModelColumnsfilter and values.
                    //Use that model list in view to give values to the textboxes.
              //      model.FilteringValue[i].Key = item.Key;
               //     model.FilteringValue[i].Value = item.Value;
                }
            }
            return PartialView("_ItemsToPlanGrid", model);

哪个工作还可以。一旦文本框填满，就将设置cookie，这很好。

错误出现在这里：

 for (int i = 0; i < model.ColumnsFilter.Count; i++)
        {
            foreach(var item in model.ColumnsFilter)
            {
                //Fill list with ModelColumnsfilter and values.
                //Use that model list in view to give values to the textboxes.
                model.FilteringValue[i].Key = item.Key;
                model.FilteringValue[i].Value = item.Value;
            }
        }

我想将字典中的项目存储在一个列表中，所以我可以用该值填充视图中的文本框。

  

System.ArgumentOutOfRangeException：'索引超出范围。一定是   非负数且小于集合的大小。'