ComboBox SelectedValue correctly sets SelectedValue in Viewmodel but not in View

Question

In my Project my selectedvalue sets correctly in viewmodel but my view not sets its selectedvalue

in xaml code:

 <ComboBox ItemsSource="{Binding AllValues}" SelectedValue="{Binding SelectedValue,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" Width="150" Margin="5,0,0,0">

in ViewModel:

public Model SelectedValue
        {
            get
            {
                return _model.Value;
            }
            set
            {
                 _model.Value = value;
                if (CVSCollection.View != null)
                    CVSCollection.View.Refresh();
                RaisePropertyChanged("SelectedValue");
            }
        }

Answer 1

I have solved by my own as i have set local variable for selectedvalue as _selectedValue and into constructor i have set _selectedValue..

Answer 2

Try using a ICollectionView in combination with IsSynchronizedWithCurrentItem. The ICollectionView takes care of all your combobox related actions. You could also set the current selected item.

Xaml:

  <ComboBox ItemsSource="{Binding AllValues}"  
                  IsSynchronizedWithCurrentItem="True"
                  Width="150" 
                  Margin="5,0,0,0"/>  

ViewModel

using System;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows.Data;

namespace ComboBoxBinding
{
    public class ViewModelSpike : INotifyPropertyChanged
    {
        private ObservableCollection<Model> _allValues = new ObservableCollection<Model>();
        private Model _selectedValue;

        public ObservableCollection<Model> AllValues
        {
            get { return _allValues; }
            set { _allValues = value; OnPropertyChanged("AllValues");}
        }

        public Model SelectedValue
        {
            get { return _selectedValue; }
            set { _selectedValue = value; OnPropertyChanged("SelectedValue");}
        }

        public ICollectionView ModelsView { get; private set; }

        public ViewModelSpike()
        {
            //First init / load AllValues here...

            ModelsView = CollectionViewSource.GetDefaultView(AllValues);
            ModelsView.CurrentChanged += OnCurrentModelChanged;

            //You can also set the current selected item / initial selected item
            //ModelsView.MoveCurrentTo(DesiredModel from AllValues)
        }

        private void OnCurrentModelChanged(object sender, EventArgs e)
        {
            if (ModelsView.CurrentItem == null) return;
            var selectedValue = ModelsView.CurrentItem as Model;

            if (selectedValue == null) return;

            SelectedValue = selectedValue;

            if (CVSCollection.View != null) CVSCollection.View.Refresh();
        }

        public event PropertyChangedEventHandler PropertyChanged;

        protected virtual void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}