Question

I am working on a website and I am trying to move simple variables, like strings and Ints back and forth with little impact. That being said, I set some variables in both TempData, and ViewData Dictionaries. I then navigate to the appropriate view, When done with that I go back to the original view where I got the variables. Then I try and navigate back to the view, and all of sudden I get this error…

    An item with the same key has already been added. 

I am absolutely dumbfounded. I have some if statements to check if the key is in the dictionary. What the heck am I doing wrong?

    [OutputCache(CacheProfile = "ZeroCacheProfile")]
    public ActionResult TemplateInfo(string PopulationID)
    {
        client.ChannelFactory.Credentials.Windows.AllowedImpersonationLevel = System.Security.Principal.TokenImpersonationLevel.Impersonation;
        string msg = (TempData.ContainsKey("message") ? TempData["message"].ToString() : "");
        TempData["message"] = msg;

        //XSLTACOData template = repo.getPatAcoDat(int.Parse(PopulationPatientID));
        //GetPatientTemplateStr("unimportant");
        //List<XSLTACOData> templates = repo.SelectListACOData(int.Parse(PopulationPatientID));

        //XmlDocument Templates = repo.SelectTemplateInfoXML(int.Parse(PopulationPatientID));
        //Templates.Load("");
        //ACOServiceReference.ACOServiceClient client = new ACOServiceReference.ACOServiceClient();

        //ACOServiceRefrence.searchPopulationbyOwnerResponse resp = client.GetOwnedPopulations();

        //string xmlString = client.GetACOData("122");//.GetPopulationPatient("121");
        string templates = "";
        try
        {
            templates = client.GetACOData(PopulationID);
            if (templates == null)
            {
                string site = "PopInfoErrSite";
                site = "PopInfoErrSite";
                View("PopInfoErrSite", site);
            }
        }
        catch (Exception ex)
        {
            string errorStr = ex.InnerException.Message;
            View("PopInfoErrSite", errorStr);
        }
        int PopulationPatID = Int32.Parse(PopulationID);
        int Populationid = Int32.Parse(PopulationID);

        if ((ViewData["TEMPLATES"] == null) || (ViewData.ContainsKey("TEMPLATES")==false))
        {
            ViewData.Add("TEMPLATES", templates);
        }
        if ((TempData.ContainsValue(PopulationID) == false) || (TempData.ContainsKey("POPULATIONID") == false))
        {
            TempData.Add("POPULATIONID", Populationid);
        }            
        //string nullStrToCheckViewDataValue = "I am putting this string here so I can check the value of ViewData[\"TEMPLATES\"] before the view is returned.  Good day sir";
        //nullStrToCheckViewDataValue.
        return View("TemplateInfo");
    }

Above is the code for the view… What on earth am I doing wrong?

Answer 1

You have to do some logging to know what exact values are in Data before error

It could be somewhere here

if ((TempData.ContainsValue(PopulationID) == false) ||
 (TempData.ContainsKey("POPULATIONID") == false))

Now, if TempDate contains that key but value is null it throws exception on trying to add key

Try something like this to get more info

try
{
    if ((TempData.ContainsValue(PopulationID) == false) || (TempData.ContainsKey("POPULATIONID") == false))
    {
        TempData.Add("POPULATIONID", Populationid);
    }

}
catch (Exception ex)
{

    throw new Exception(ex.Message + " containsValue=" + TempData.ContainsValue(PopulationID) 
        + " containsKey=" + TempData.ContainsKey("POPULATIONID"));
}

and the same for templates