Having a hard time binding my viewmodel class to my view, what am I doing wrong?

Question

I've got a ViewModel class named SpecMapViewModel. I've got it referenced in the Window tag of a window, like this:
xmlns:vm="clr-namespace:SpecMapException.ViewModels"
Next I have it in the Window.Resources section like this:
<vm:SpecMapViewModel x:Key="SpecMapVM" />
And lastly I've trying to bind it to a ComboBox, like this:
<ComboBox x:Name="cmbSources"
DisplayMemberPath="CdValue"
MinWidth="100"
ItemsSource="{Binding ObsSpecimenSources}"
SelectedValue="{Binding CdValue}"
SelectedValuePath="CdValue" />
I've both put a DataContext attribute in the ComboBox's tag, and I've also tried assigning the DataContext in the Window_Loaded event. Neither has worked.
So what am I doing wrong?
Rod

Answer 1

Hi Doctor-Who,
Based on your code snippet, I could not find some issue, I suggest that you could check the DataContext was assigned in a right way. Then I have made a code sample, I assigned the DataContext to window, and the same as your ComboBox. You could refer to it,
and find some different with your code. I hope it would be helpful to solve you question.
<StackPanel>
<ComboBox DisplayMemberPath="CdValue"
MinWidth="100"
ItemsSource="{Binding ObsSpecimenSources}"
SelectedValue="{Binding CdValue}"
SelectedValuePath="CdValue"></ComboBox>
</StackPanel>
SpecMapViewModel.cs
class SpecMapViewModel : INotifyPropertyChanged
private ObservableCollection<SpecMap> _ObsSpecimenSources;
public ObservableCollection<SpecMap> ObsSpecimenSources
get { return _ObsSpecimenSources; }
set
if(value != null)
_ObsSpecimenSources = value;
OnPropertyChanged("ObsSpecimenSources");
public SpecMapViewModel()
ObsSpecimenSources = new ObservableCollection<SpecMap>();
ObsSpecimenSources.Add(new SpecMap {CdValue="abc" });
ObsSpecimenSources.Add(new SpecMap { CdValue = "def" });
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string PropertyName)
PropertyChangedEventHandler handler = PropertyChanged;
if(handler != null)
handler(this,new PropertyChangedEventArgs(PropertyName));
private void Window_Loaded(object sender, RoutedEventArgs e)
SpecMapViewModel viewmodel = new SpecMapViewModel();
this.DataContext = viewmodel;
Best Regards,
Xavier Eoro
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