3

我有一个IList<IHtmlString>我想添加一些元素的。由于短时间内它会抛出一个ArrayTypeMismatchException，但我不知道为什么。从 HttpSessionStateBase 添加或访问元素时也会发生这种情况。

public class HtmlList 
{
  private IList<IHtmlString> _listItems = new List<IHtmlString>();

  public void Add(IHtmlString listItem)
  {
    if (listItem != null)
    {
      _listItems.Add(listItem); // here ArrayTypeMismatchException is thrown
    }
  }
}

有人可以向我解释一下吗？为什么过去三年没有发生这种情况？从 .NET 4.0 更改为 4.5 后，我第一次遇到异常。

堆栈跟踪：

在 System.Collections.Generic.List`1.Add(T item)
在 MyCompany.Web.Mvc.UI.HtmlList.Add(IHtmlString element)
在 MyCompany.Web.Mvc.Models.CaptchaExtensions.CaptchaImageElement.ToString()
在 MyCompany .Web.Mvc.Models.CaptchaExtensions.CaptchaImageElement.Render(Int32 width, Int32 height)
at ASP.views_teilnahme_index_aspx.__RenderContent3(HtmlTextWriter __w, Control parameterContainer)
at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
在 System.Web.UI.Control.Render(HtmlTextWriter writer)
在 System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter 适配器)
在 System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
在 System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
在 System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
在 System .Web.UI.Control.RenderChildren(HtmlTextWriter writer)
在
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)在 System.Web.UI.Control.Render(HtmlTextWriter writer)
在 System.Web.UI。 Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
在 System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
在 System.Web.UI.Page.Render(HtmlTextWriter writer)
在 System.Web.Mvc.ViewPage.Render(HtmlTextWriter writer)
在 System.Web.UI.Control .RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
at System.Web.UI.Page.ProcessRequestMain （布尔型 includeStagesBeforeAsyncPoint，布尔型 includeStagesAfterAsyncPoint）

4

1 回答 1

0

i am assuming that IHtmlString is defined in the System.Web namespace.

this should not happen until you have IHtmlString interface defined somewhere else in your code and you are implementing a class with your IHtmlString interface and adding it to list

Please check this ,

于 2013-03-21T12:03:41.723 回答