CODEWITHSUNDEEP
wpfvb.netlinqxamlbinding
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Raizzen

Reputation: 192

How to add ListView Items via Binding by Entity Framework / Linq

How to add ListView Items via binding by Entity Framework / Linq?

I got my ListView in the xaml with bindings here:

<ListView x:Name="lstvw_Overview" HorizontalAlignment="Left" Height="310" Margin="11,89,0,0" VerticalAlignment="Top" Width="676">
        <ListView.View>
            <GridView>
                <GridViewColumn Header="Adresse" DisplayMemberBinding="{Binding address}"/>
            </GridView>
        </ListView.View>
</ListView>

This is my code

Public Sub New()
    Initialize()
End Sub
Dim address As String
Dim items As ObservableCollection(Of Uebersicht)
Public Structure Uebersicht
    Private _address As String
    Public Property address As String
        Get
            Return _address
        End Get
        Set(value As String)
            _address = value
        End Set
    End Property
End Structure
Sub Initialize()
    InitializeComponent()
    fillListView()
End Sub
 Sub fillListView()
    Using container As New infrastrukturDB_TESTEntities1
        Dim mailAddressList = From tbl_unzustellbarAdressen In container.tbl_unzustellbarAdressen
        For Each mail In mailAddressList
            address = mail.unzustellbarMail.ToString()
            Try
                items.Add(New Uebersicht With {.address = address})
            Catch ex As Exception
                MessageBox.Show("Error")
            End Try

        Next
    End Using
End Sub

EDIT: tried the ObserverableCollection but now i got a NullReferenceException! If i debug, address got data.. not null

Upvotes: 1

Views: 990

Answers (1)

mm8
mm8

Reputation: 169320

Since you are adding strings to the ListView, you should not bind to the address property but the source object itself:

<ListView x:Name="lstvw_Overview" HorizontalAlignment="Left" Height="310" Margin="11,89,0,0" VerticalAlignment="Top" Width="676">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="Adresse" DisplayMemberBinding="{Binding}"/>
        </GridView>
    </ListView.View>
</ListView>

Edit: You need to intialize the ObservableCollection before you can add items to it. And to be able to bind to the ObservableCollection, you must expose it as a property:

Public Sub New()
    Initialize()
End Sub

Dim address As String

Private _items As ObservableCollection(Of Uebersicht) = New ObservableCollection(Of Uebersicht) 
Public Property Items As ObservableCollection(Of Uebersicht)
    Get
        Return _items
    End Get
    Set(value As ObservableCollection(Of Uebersicht))
        _items = value
    End Set
End Property

Sub Initialize()
    InitializeComponent()
    DataContext = Me
    fillListView()
End Sub

XAML:

<ListView ItemsSource="{Binding Items}" HorizontalAlignment="Left" Height="310" Margin="11,89,0,0" VerticalAlignment="Top" Width="676">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="Adresse" DisplayMemberBinding="{Binding address}"/>
        </GridView>
    </ListView.View>
</ListView>

Upvotes: 4

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