页面在IIS7.5中返回异常，在VS2010调试中运行良好

Question

Adding some code to an existing MVC webpage. All other parts of the site continue to work fine. Running Debug in VS2010, the code functions correctly. After uploading to IIS 7.5 it returns the exception below. Any ideas? Can provide additional code if needed.

Thanks

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Value cannot be null.
Parameter name: String

   at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
   at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
   at System.Int32.Parse(String s)
   at McCarterMobile.Controllers.CartController.RemoveContribution(FormCollection form) in V:\Google Drive\Websites\Mobile Site\McCarterMobile\Controllers\CartController.cs:line 391
   at lambda_method(Closure , ControllerBase , Object[] )
   at System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters)
   at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
   at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass15.<InvokeActionMethodWithFilters>b__12()
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)
   at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass15.<>c__DisplayClass17.<InvokeActionMethodWithFilters>b__14()
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
   at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)

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Here is the controller code.

383            public ActionResult RemoveContribution(FormCollection form)
384        {
385            string sessionKey = "";
386
387            if (HttpContext.Request.Cookies[FormsAuthentication.FormsCookieName] != null)
388            {
389                {
390                    sessionKey = FormsAuthentication.Decrypt(HttpContext.Request.Cookies[FormsAuthentication.FormsCookieName].Value).UserData;
391                    repository.RemoveContribution(sessionKey, int.Parse(form["Ref_Num"]));
392                }
393                return RedirectToAction("Index");
394            }
395            else
396            {
397                return RedirectToAction("File Not Found", "Errors");
398            }
399        }

---

Here is the cshtml code

@using (Html.BeginForm("RemoveContribution", "Cart"))
{
<input type="submit" data-role="button" data-inline="true" data-iconpos="notext" data-icon="delete" data-iconpos="right" />
<input type=hidden name=Ref_Num value='@c.RefNum' />
}

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Answer 1

The MVC framework will handle the type conversions and such for you if you let it:

public ActionResult RemoveContribution(int? Ref_Num = null)
{
    if (Ref_Num == null)
    {
        // report an error or whatever
    }
    else
    {
        // do something with Ref_Num
    }
}

There's a lot of code in the MVC framework to support this stuff so that you don't have to keep dealing with type conversions and such.