cant pass list

Question

I am using silverlight3 to use a webservice to update a DB.

I cant pass a list of string to a service refernce service1.svc file.
I have tried many variations but I dont understand the error

ErrorValue of type 'System.Collections.Generic.List(Of String)' cannot be converted to 'System.Collections.ObjectModel.ObservableCollection(Of String)'.

 

this recieves the 3rd paramter

    <OperationContract()> _
Public Sub updatedataTest(ByVal myid As String, ByVal totalCorrect As Integer, ByVal mytestList As List(Of String))

I pass this list to the above by

 Public Sub updateDataTest(ByVal type As Integer, ByVal mytestList As List(Of String))
        Dim webservice2 As New trigTrainer4.ServiceReference1.Service1Client
        Dim myresultsList As New List(Of String)

              myresultsList = mytestList
            webservice2.updatedataTestAsync(myid, totalCorrect, myresultsList)
       

I get the  list string by

 Public ReadOnly Property myResultsTestList() As List(Of String)
        Get
            Return mytestList
        End Get

    End Property

Answer 1

Change myresultsList to an ObservableCollection, then on this line

myresultsList = mytestList

cast  mytestList as an OC.

Answer 2

If the myTestList is a List, you cannot directly cast it to a ObservableCollection.  You will have to go through a for-loop process to copy the items over.

ObservableCollection<string> myresultsList = new ObservableCollection<string>();

foreach (string s in mytestlist)
{
   myresultsList.Add(s);
}

 

Answer 3

Right, in SL3, but in SL4 you can? 

Answer 4

List<string> listStrings = new List<String>();
ObservableCollection<string> ocStrings = new ObservableCollection<string>();

listStrings.Add("Hello");
listStrings.Add("World");

// Following failed to convert
//obString = (ObservableCollection<string>)listStrings;

// This one works
ocStrings = new ObservableCollection<string>(listStrings);

// This one also works
ocStrings = new ObservableCollection<string>();
foreach (String s in listStrings)
    ocStrings.Add(s);

 

Answer 5

That error occurs because your webService is configured with the ObservableCollection.. And you are passing List which is Generic.

To resolve this problem, Configure your Service Reference by right clicking on Service Reference.

Now change the Collection type to the Generic.List from ObservableCollection.

Plz try this one..

and reply if this one useful...

Answer 6

ok i did this a while back but WCF is not working when i deployed on the host.

It has been awful to use as it works on my PC but not in the host.

check my other posts on it.