WPF Listview SelectionChanged event
I don't know if you still need help with this, but I solved this problem by making a variable that tracks the selectedindex, in my case -- when initially bound it's always 0 so it's a little easier for me to do, however if you inform the viewmodel of the appropriate index, I simply added a
ComboBox box = e.OriginalSource as ComboBox;
if (_previousIndex == cb.SelectedIndex) return;
//do stuff you need to do with a new SelectedIndex
The listView should not fire the SelectionChange if you only set the ItemsSource property. However if you bind the SelectedIndex property to a property of your dataContext object the selection will move to the index that is specified by the binded property.
this doesn't fires the Selector_OnSelectionChanged event when the page loads:
<ListView SelectionChanged="Selector_OnSelectionChanged"
ItemsSource="{Binding Path=Items}"
></ListView>
but this does:
<ListView SelectionChanged="Selector_OnSelectionChanged"
SelectedIndex="{Binding Path=SelectedIndexValue}"
ItemsSource="{Binding Path=Items}"
></ListView>
because the SelectedIndex is set to the SelecteIndexValue through binding.
To avoid this and still keep the bindings in your markup set the SelectedIndexValue of your dataContext object to -1 before binding (Before InitializeComponent() is called in your form constructor).
Hope this helps.
thanks for the responses.
When I put a breakpoint on the SelectionChanged event, it breaks proceedings there before the screen is fully loaded. You will also see that the first row is 'selected' afterwards on the list. I am not binding to a SelectedIndexValue as you can see in the code. The DataContext for the list is a ReadonlyCollection
In my SelectionChanged event as you can see I notify other objects to be loaded with data relating to the selected item. I only want this to happen when one is selected but not a default one to be set. I have to of these ListViews representing similar data but on loaded none must have an item selected.
I have noticed that the default Selected index is set to -1 on the properties window for the Listview. I can even set this is code on the List_Loaded event, but by then the first SelectionChanged has happened already.
<ListView PreviewMouseDown="ActiveCasesView_MouseDown" x:Name="ActiveCasesView"
DataContext="{StaticResource ActiveCasesViewSource}"
ItemsSource="{Binding}"
ItemTemplate="{StaticResource CasesItemTemplate}"
SelectionMode="Single"
SelectionChanged="ActiveCasesView_SelectionChanged"
ScrollViewer.CanContentScroll="True"
ScrollViewer.VerticalScrollBarVisibility="Auto" >
</ListView>
private void ActiveCasesView_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (mouseClicked)
if (e.AddedItems.Count > 0)
App.Messenger.NotifyColleagues(App.MSG_SELECT_ACTIVE_CASE, ((CaseViewModel)ActiveCasesView.SelectedItem).CaseNumber);
}
I added the PreviewMouseDown to set an indicator that I have clicked on the listview in the SelectionChanged event. This does help but I'm not convinced that its the best solution.
Thanks Petrus