Insert a break point in the mainpage.aspx.vb code
And put e.result in your watch window by dragging or by
right clicking the text and selecting "Add watch".
e.result is of type ObservableCollection. The way I
interpret this type is that Silverlight keeps a link to this collection. When
we change this collection, it will be visible in the datagrid without having to
bind it again.
New code for Mainpage.aspx.vb
Imports System.Collections.ObjectModel
Partial Public Class MainPage
Inherits UserControl
Public WithEvents MyList As ObservableCollection(Of ServiceReference1.Contact)
Public Sub New()
InitializeComponent()
Dim proxy As ServiceReference1.Service1Client = New
ServiceReference1.Service1Client
AddHandler proxy.FindContactListCompleted, AddressOf GetContactcompleted
proxy.FindContactListAsync()
End Sub
Sub GetContactcompleted(ByVal sender As Object, ByVal e As
ServiceReference1.FindContactListCompletedEventArgs)
MyList = e.Result
DataGrid1.ItemsSource = MyList
End Sub
End Class
Here a public variable MyList of type ObservableCollection
is inserted. It is part of the System.Collections.ObjectModel which is
imported.
When running your application, the result will be the same.
But changing the content of the datagrid will automatically change the content
of MyList. And this can be handled in code.
New code for Mainpage.aspx.vb
Imports System.Collections.ObjectModel
Partial Public Class MainPage
Inherits UserControl
Public WithEvents MyList As ObservableCollection(Of ServiceReference1.Contact)
Public Sub New()
InitializeComponent()
Dim proxy As ServiceReference1.Service1Client = New
ServiceReference1.Service1Client
AddHandler proxy.FindContactListCompleted, AddressOf GetContactcompleted
proxy.FindContactListAsync()
End Sub
Sub GetContactcompleted(ByVal sender As Object, ByVal e As
ServiceReference1.FindContactListCompletedEventArgs)
MyList = e.Result
DataGrid1.ItemsSource = MyList
MyList.Add(New ServiceReference1.Contact() With { _
.IDContact = 101, _
.Name = "new", _
.Address = "", _
.City = "" _
})
End Sub
End Class
In this code a new record is inserted into MyList. Although
Datagrid1 has been connected before to MyList, changes in MyList still will be
visible in the datagrid.
I would like to hide the third column in the datagrid. It
should not be visible. I would expect hiding the column in
Sub GetContactcompleted(ByVal sender As Object, ByVal e As
ServiceReference1.FindContactListCompletedEventArgs)
MyList = e.Result
DataGrid1.ItemsSource = MyList
MyList.Add(New ServiceReference1.Contact() With { _
.IDContact = 101, _
.Name = "new", _
.Address = "", _
.City = "" _
})
DataGrid1.Columns(3).Visibility = Windows.Visibility.Collapsed
End SubWould hide this column.
But this will result in an error.
Datagrid columns are created after the entire code is
finished and can not be handled in this subroutine. A solution may be to manually
create the columns in the datagrid. This will be shown later.
What you can do is change the result from the service using
ILinq
Using ILinq in the result
Sub GetContactcompleted(ByVal sender As Object, ByVal e As
ServiceReference1.FindContactListCompletedEventArgs)
MyList = e.Result
MyList.Add(New ServiceReference1.Contact() With { _
.IDContact = 101, _
.Name = "new", _
.Address = "", _
.City = "" _
})
Dim TopData = From NewData In MyList
Order By NewData.Name Descending
Take (2)
DataGrid1.ItemsSource = TopData
End SubGives this
