Question

I am currently trying to combine two collections into one for binding to a combobox. I first started out with two static collections built within a class:

public partial class MainPage : UserControl
{
    //create static observable collection
    private ObservableCollection<string> items;

    public ObservableCollection<string> Items
    {
        get
        {
            return this.items;
        }
        set
        {
            if (this.items != value)
            {
                this.items = value;
            }
        }
    }

    protected ObservableCollection<string> StaticItems
    {
        get
        {
            return new ObservableCollection<string>() { "Select User", "Select All" };
        }
    }

    //create dynamic observable collection

    public MainPage()
    {
        InitializeComponent();
        this.items = this.StaticItems;
        this.comboBox1.ItemsSource = this.Items;
    }

    private void UserControl_Loaded(object sender, RoutedEventArgs e)
    {
        foreach (var item in GetDynamicItems())
        {
            this.Items.Add(item);
        }
    }

    private List<string> GetDynamicItems()
    {
        return new List<string>() { "User1", "User2", "User3" };

    }

The above works as desired.
What I would like to do now is to initate a query to a service and have the results of that service appended to the collection instead of User1, USer2,USer3

I create a query to the service as:

private void FillOfficerList()
{
    QueryClient qc = new QueryClient("BasicHttpBinding_IQuery");
    qc.GetOfficerNamesCompleted += new EventHandler<GetOfficerNamesCompletedEventArgs>(qc_GetOfficerNamesCompleted);
    qc.GetOfficerNamesAsync();
}

public void qc_GetOfficerNamesCompleted(object sender, GetOfficerNamesCompletedEventArgs e)
{
    // Now how do I add e.Results to above collection?
}

The query works I am just stuck on how to take the results ( e.Results) and bind/concat them to the Items collection. Any pointers or tips would be appreciated.

Note: This is for silverlight so using a composite collections approach does not seem to be an option as the class is not supported.

Thanks in advance

Answer 1

I just read your comment. Since you have the ObservableCollection with 3 strings and 1 int. Try doing this.

Lets assume you are having a Class say myClass which has the 3 strings and 1 int.

public class myClass()
{
   string str1 {get; set;}
   string str2 {get; set;}
   string str3 {get; set;}
   int int1 {get; set;}
}

Create an ObservableCollection in the client side with the same datatype.

ObservableCollection<myClass> collection = new ObservableCollection<myClass>();


public void qc_GetOfficerNamesCompleted(object sender, GetOfficerNamesCompletedEventArgs e)   
{   
 // Now try adding this code  
for(int i=0; i<e.Result.Count;i++)  
{  
     // I do this because, I don't want the Client class to be unaware of the class myClass
     collection.Add(new myClass()
           {
             str1 = e.Result[i].str1,
             str2 = e.Result[i].str2,
             str3 = e.Result[i].str3,
             int1 = e.Result[i].int1       
          });
}   

for(int i=0; i<collection.Count;i++)
{
   Items.Add(collection[i].str1); // Add the string you want. I ve used str1 here.
}

}

Hope this helps.