Http.GetAsync (URI); The message "The parameter is incorrect".

Following the example of my video on Channel 9 Developing Universal Windows Apps with C # and XAML: (05) Create a Service "for" Create a Service "I managed to get it back online in March 2015, have made a lot of additions to my project since then and the system and now I will return to the continuation of this part of my project.

Running in debug mode doesn't give me a specific reason why it fails other than:

-       e   {Windows.UI.Xaml.UnhandledExceptionEventArgs}   Windows.UI.Xaml.UnhandledExceptionEventArgs
-       Exception   {"The parameter is incorrect.\r\n\r\nThe parameter is incorrect.\r\n"}  System.Exception {System.ArgumentException}
+       [System.ArgumentException]  {"The parameter is incorrect.\r\n\r\nThe parameter is incorrect.\r\n"}  System.ArgumentException
-       Data    {System.Collections.ListDictionaryInternal} System.Collections.IDictionary {System.Collections.ListDictionaryInternal}
+       [System.Collections.ListDictionaryInternal] {System.Collections.ListDictionaryInternal} System.Collections.ListDictionaryInternal
    IsFixedSize false   bool
    IsReadOnly  false   bool
+       Keys    {System.Collections.ListDictionaryInternal.NodeKeyValueCollection}  System.Collections.ICollection {System.Collections.ListDictionaryInternal.NodeKeyValueCollection}
+       Values  {System.Collections.ListDictionaryInternal.NodeKeyValueCollection}  System.Collections.ICollection {System.Collections.ListDictionaryInternal.NodeKeyValueCollection}
-       Results View    Expanding the Results View will enumerate the IEnumerable   
-       [0] {System.Collections.DictionaryEntry}    object {System.Collections.DictionaryEntry}
    Key "RestrictedDescription" object {string}
    Value   "The parameter is incorrect.\r\n"   object {string}
+       Non-Public members      
-       [1] {System.Collections.DictionaryEntry}    object {System.Collections.DictionaryEntry}
    Key "RestrictedErrorReference"  object {string}
    Value   null    object
+       Non-Public members      
-       [2] {System.Collections.DictionaryEntry}    object {System.Collections.DictionaryEntry}
    Key "RestrictedCapabilitySid"   object {string}
    Value   null    object
+       Non-Public members      
-       [3] {System.Collections.DictionaryEntry}    object {System.Collections.DictionaryEntry}
    Key "__RestrictedErrorObject"   object {string}
-       Value   {System.Exception.__RestrictedErrorObject}  object {System.Exception.__RestrictedErrorObject}
-       RealErrorObject COM Object  object {System.__ComObject}
+       base    COM Object  System.MarshalByRefObject {System.__ComObject}
+       Non-Public members      
+       Interface View      
-       Dynamic View    Expanding the Dynamic View will get the dynamic members for the object  
    Empty   "No further information on this object could be discovered" string
+       Non-Public members      
+       Non-Public members      
-       [4] {System.Collections.DictionaryEntry}    object {System.Collections.DictionaryEntry}
    Key "__HasRestrictedLanguageErrorObject"    object {string}
    Value   false   object {bool}
+       Non-Public members      
    HelpLink    null    string
    HResult -2147024809 int
+       InnerException  null    System.Exception
    Message "The parameter is incorrect.\r\n\r\nThe parameter is incorrect.\r\n"    string
    Source  ""  string
    StackTrace  null    string
    TargetSite  null    System.Reflection.MethodBase
+       Static members      
+       Non-Public members      
    Handled false   bool
    Message "The parameter is incorrect.\r\n"   string

      

        
        
        
      

    

I have read and applied this " Error message: parameter is invalid " resolution on Microsoft support site with no success. Since I have multiple language packs installed but the default is set to "English" so I can't see how this causes a failure.

My MainPageViewModel that handles OnNavigatedTo and http.GetAsync (uri):

public async System.Threading.Tasks.Task<T> GetAsync<T>(Uri uri)
{
    using (var http = new Windows.Web.Http.HttpClient())
    {
        http.DefaultRequestHeaders.Add("Accept", "application/json");
        var response = await http.GetAsync(uri);
        if (response.StatusCode != Windows.Web.Http.HttpStatusCode.Ok)
            throw new Exception(response.StatusCode.ToString());
        string json = await response.Content.ReadAsStringAsync();
        return Newtonsoft.Json.JsonConvert.DeserializeObject<T>(json);
    }
}

public async override void OnNavigatedTo(object navigationParameter, NavigationMode navigationMode, Dictionary<string, object> viewModelState)
{
    try
    {
        var service = System.IO.Path.Combine(this._settings.WebApiBase, Parameters.TSUser);
        var tsuser = await GetAsync<IEnumerable<NathsarTS.DataModels.Models.TSUser>>(new Uri(service));

      

        
        
        
      

    

other parts of the project that make up the fields above:

    public class Settings : ISettings
    {
        public Settings()
        {
            WebApiBase = "http://localhost:58317/api/";
     ...
    }

    public static class Parameters
    {
        public const string TSUser = "TSUsers";
     ...
    }

    public class TSUsersController : ApiController
    {
        private NathsarTSEntities db = new NathsarTSEntities();

        // GET: api/TSUsers
        public IQueryable<TSUser> GetTSUsers()
        {
            return db.TSUsers;
        }
     ...
    }

      

        
        
        
      

    

The exception message after running it:

The value does not fall within the expected range.

What else do I need to check to get this working?

Additional research:

After building a basic app with WebApi (2014 SQLExpress Edmx) and PCL (for my generic table classes) I found something like a bazaar when doing http.GetAsync (uri), I get ListBox related Exception I am using:

• ) I am implementing Window Phone Pivot which I got from Window Dev Center project for My Windows App Universal Solution. XAML FlipView Sample Control
• This project uses SeletedItem to bind to FlipView, in which case it does not throw an exception when executing http.GetAsync (uri),
• however, when I use SelectedIndex I get an Exception.
• the reason for using http.GetAsync (uri) is to fetch items for ListBox from SQLExpress 2014 database and for some reason it throws this exception.

Current solution:

My acceptable job was to remove the binding from the XAML and create it in code:

var service = System.IO.Path.Combine("http://localhost:53397/api/", "TSPivotMenus");
var tspivotmenus = await GetAsync<IEnumerable<TSPivotMenu>>(new Uri(service));

this.TSMainMenu.ItemsSource = tspivotmenus;
Binding binding = new Binding
{
    Path = new PropertyPath("SelectedIndex"),
    Mode = BindingMode.TwoWay,
    ElementName = this.TSMainFlipView.Name
};
this.TSMainMenu.SetBinding(ListBox.SelectedIndexProperty, binding);

      

        
        
        
      

    

But it would be great to find out why this is happening!

My conclusion:

After further research and meditation, the only thing I can figure out why this exception is being thrown is when the ListBox has no items to select, or by default, while waiting for an async method so I can fill it with items.

So http.GetAsync (uri) doesn't actually raise the Exception directly, but in-direct because I need the data from it for the ListBox .

If anyone has time to check and confirm this, I can mark it as Answered .