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MVC中使用ViewBag传递数据报错 值不能为 null。 参数名: virtualPath RRS feed

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    值不能为 null。
参数名: virtualPath

说明: 执行当前 Web 请求期间，出现未经处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。 

异常详细信息: System.ArgumentNullException: 值不能为 null。
参数名: virtualPath

源错误: 


行 5:  @{
行 6:      var partinfos = ViewBag.partinfo != null ? (List<original_part_info>)ViewBag.partinfo : null;
行 7:      var subjectlist = ViewBag.subjectlist as List<SelectListItem>;
行 8:  }
行 9:  

源文件: e:\SVN\Solution_Comic_v1.0\Admin_v2\Views\xxxxxx\BookInfo.cshtml    行: 7 

堆栈跟踪: 


[ArgumentNullException: 值不能为 null。
参数名: virtualPath]
   System.Web.VirtualPath.Create(String virtualPath, VirtualPathOptions options) +9926013
   System.Web.VirtualPathUtility.Combine(String basePath, String relativePath) +30
   System.Web.WebPages.UrlUtil.Url(String basePath, String path, Object[] pathParts) +17
   System.Web.WebPages.WebPageExecutingBase.Href(String path, Object[] pathParts) +25
   ASP._Page_Views_Original_BookInfo_cshtml.Execute() in e:\SVN\Solution_Comic_v1.0\Admin_v2\Views\Original\BookInfo.cshtml:7
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +196
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +127
   System.Web.WebPages.StartPage.RunPage() +19
   System.Web.WebPages.StartPage.ExecutePageHierarchy() +62
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +76
   System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +259
   System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +115
   System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +294
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) +15
   System.Web.Mvc.<>c__DisplayClass1a.<InvokeActionResultWithFilters>b__17() +23
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) +242
   System.Web.Mvc.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() +25
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) +242
   System.Web.Mvc.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() +25
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) +175
   System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +89
   System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +102
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +58
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +44
   System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +15
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +58
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +54
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +58
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +44
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +12
   System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +25
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +58
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +44
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +11
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9644037
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

    @model EFDal.Models.original_book_info
@using EFDal.Models;
@using EFDal.Models.Enums;
@{
    var partinfos = ViewBag.partinfo != null ? (List<original_part_info>)ViewBag.partinfo : null;
    var subjectlist = ViewBag.subjectlist as List<SelectListItem>;
}



  public ActionResult BookInfo(int bookid)
        {
            using (xxxContext db = new xxxContext(ContextType.xxxlRead))
            {
                var bookinfo = db.aa.Find(bookid);
                var partinfo = db.cc.Where(x => !x.isdelete && !x.ispause && x.bookid == bookid).ToList();
                if (partinfo.Count > 0)
                {
                    ViewBag.partinfo = partinfo;
                }
                var subjectlist = vv.BLL.CommonHelper.ss(false);
                ViewBag.subjectlist = subjectlist;
                return View(bookinfo);
            }
        }

    大神求助呀  找了好久没找到是什么原因哎.....


    2016年1月4日 6:33
    |

答案

  • Question
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    0
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    你好，

    我觉得问题可能在于subjectlist，你从数据库返回的是Null。你可以设置一个断点查看一下。

    另外，我建议你参考下面的代码：

    Controller中的代码：

                List<SelectListItem> list = new List<SelectListItem>();
            list = context.Employees.Select(c => new SelectListItem() { Text = c.City, Value = c.Country }).ToList();
            ViewBag.CountryList = list;

    View中的代码：

           @Html.DropDownList("ddl", (IEnumerable<SelectListItem>)ViewBag.CountryList)

    2016年1月5日 2:28
    |
    版主