We Keep Coding

Dynamically filtering a CollectionViewSource bound to a SelectedItem via MVVM

I've been digging back into some projects in WPF, and come across a hurdle that I haven't been able to find a directly related solution for.
Essentially I want to filter a child property of a SelectedItem dynamically (via text entered in the filter box, something along the lines of .Contains(filter)). The UI displays correctly in the sample project, but after attempting to implement solutions from every hit possible on SO or otherwise, I've come up blank, or making serious compromises to the MVVM pattern.
ParentItem:
public class ParentItem
{
public string Name { get; set; }
public List<string> ChildItems { get; set; }
public DateTime CreatedOn { get; set; }
public bool IsActive { get; set; }
public ParentItemStatus Status { get; set; }
}
public enum ParentItemStatus
{
Status_One,
Status_Two
}
ViewModel:
public class MainWindowViewModel : ViewModelBase
{
public ObservableCollection<ParentItem> ParentItems { get; set; }
public MainWindowViewModel()
{
ParentItems = new ObservableCollection<ParentItem>();
LoadDummyParentItems();
}
private ICommand _filterChildrenCommand;
public ICommand FilterChildrenCommand => _filterChildrenCommand ?? (_filterChildrenCommand = new RelayCommand(param => FilterChildren((string)param), param => CanFilterChildren((string)param)));
private bool CanFilterChildren(string filter)
{
//TODO: Check for selected item in real life.
return filter.Length > 0;
}
private void FilterChildren(string filter)
{
//TODO: Filter?
}
private void LoadDummyParentItems()
{
for (var i = 0; i < 20; i++)
{
ParentItems.Add(new ParentItem()
{
Name = $"Parent Item {i}",
CreatedOn = DateTime.Now.AddHours(i),
IsActive = i % 2 == 0 ? true : false,
Status = i % 2 == 0 ? ParentItemStatus.Status_Two : ParentItemStatus.Status_One,
ChildItems = new List<string>() { $"Child one_{i}", $"Child two_{i}", $"Child three_{i}", $"Child four_{i}" }
});
}
}
}
MainWindow:
<Window x:Class="FilteringDemo.Views.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:FilteringDemo.Views"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Window.Resources>
<CollectionViewSource x:Key="ChildItemsViewSource" Source="{Binding ElementName=ItemList, Path=SelectedItem.ChildItems}" />
</Window.Resources>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width=".25*"/>
<ColumnDefinition Width=".75*"/>
</Grid.ColumnDefinitions>
<ListView x:Name="ItemList" Grid.Column="0" Margin="2" ItemsSource="{Binding ParentItems}" SelectionMode="Single">
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}"/>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<Grid Grid.Column="1">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="1*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Grid Grid.Row="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="1*"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0" Text="{Binding ElementName=ItemList, Path=SelectedItem.Name}" Margin="2"/>
<TextBlock Grid.Column="1" Text="{Binding ElementName=ItemList, Path=SelectedItem.CreatedOn}" Margin="2"/>
<TextBlock Grid.Column="2" Text="{Binding ElementName=ItemList, Path=SelectedItem.IsActive}" Margin="2"/>
<TextBlock Grid.Column="3" Text="{Binding ElementName=ItemList, Path=SelectedItem.Status}" Margin="2"/>
</Grid>
<ListView Grid.Row="1" Margin="2" ItemsSource="{Binding Source={StaticResource ChildItemsViewSource}}" />
<Grid Grid.Row="2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0" Text="Contains:" Margin="2" VerticalAlignment="Center"/>
<TextBox x:Name="ChildFilterInput" Grid.Column="1" Margin="2" />
<Button Grid.Column="2" Content="Filter" Width="100" Margin="2" Command="{Binding FilterChildrenCommand}" CommandParameter="{Binding ElementName=ChildFilterInput, Path=Text}"/>
</Grid>
</Grid>
</Grid>
</Window>
I've tried various implementations of adding a Filter event handler on the CollectionViewSource but have been unable to make them dynamic. It also seems like most examples/tutorials only deal directly with the parent item or static filters.
In a non-MVVM mindset, I was thinking to have an interaction trigger drive the selected item back into the ViewModel, and then create a filtered ICollectionView which the ChildItems ListView would bind to, but it seems like I can't be the only person trying this, and that there must be an easier MVVM binding friendly way.

The following example shows a simple solution to implement live filtering on a collection:
Person.cs
class Person
{
public Person(string firstName, string lastName)
{
this.FirstName = firstName;
this.LastName = lastName;
}
public string FirstName { get; set; }
public string LastName { get; set; }
}
ViewModel.cs
class ViewModel
{
public ViewModel()
{
this.Persons = new ObservableCollection<Person>()
{
new Person("Derek", "Zoolander"),
new Person("Tony", "Montana"),
new Person("John", "Wick"),
new Person("The", "Dude"),
new Person("James", "Bond"),
new Person("Walter", "White")
};
}
private void FilterData(string filterPredicate)
{
// Execute live filter
CollectionViewSource.GetDefaultView(this.Persons).Filter =
item => (item as Person).FirstName.StartsWith(filterPredicate, StringComparison.OrdinalIgnoreCase);
}
private string searchPredicate;
public string SearchPredicate
{
get => this.searchFilter;
set
{
this.searchPredicate = value;
FilterData(value);
}
}
public ObservableCollection<Person> Persons { get; set; }
}
MainWindow.xaml
<Window>
<Window.DataContext>
<ViewModel />
</Window.DataContext>
<StackPanel>
<TextBox Text="{Binding SearchPredicate, UpdateSourceTrigger=PropertyChanged"} />
<ListView ItemsSource="{Binding Persons}">
<ListView.View>
<GridView>
<GridView.Columns>
<GridViewColumn Header="Firstname" DisplayMemberBinding="{Binding FirstName}" />
<GridViewColumn Header="Lastname" DisplayMemberBinding="{Binding LastName}" />
</GridView.Columns>
</GridView>
</ListView.View>
</ListView>
</StackPanel>
</Window>
Update
It seems like you are having problems to filter the child items. The following example is more specific to your scenario:
DataItem.cs
class DataItem
{
public DataItem(string Name)
{
this.Name = name;
}
public string Name { get; set; }
public ObservableCollection<DataItem> ChildItems { get; set; }
}
ViewModel.cs
class ViewModel
{
public ViewModel()
{
this.ParentItems = new ObservableCollection<DataItem>()
{
new DataItem("Ben Stiller") { ChildItems = new ObservableCollection<DataItem>() { new DataItem("Zoolander"), new DataItem("Tropical Thunder") }},
new DataItem("Al Pacino") { ChildItems = new ObservableCollection<DataItem>() { new DataItem("Scarface"), new DataItem("The Irishman") }},
new DataItem("Keanu Reeves") { ChildItems = new ObservableCollection<DataItem>() { new DataItem("John Wick"), new DataItem("Matrix") }},
new DataItem("Bryan Cranston") { ChildItems = new ObservableCollection<DataItem>() { new DataItem("Breaking Bad"), new DataItem("Malcolm in the Middle") }}
};
}
private void FilterData(string filterPredicate)
{
// Execute live filter
CollectionViewSource.GetDefaultView(this.SelectedParentItem.ChildItems).Filter =
item => (item as DataItem).Name.StartsWith(filterPredicate, StringComparison.OrdinalIgnoreCase);
}
private string searchPredicate;
public string SearchPredicate
{
get => this.searchFilter;
set
{
this.searchPredicate = value;
FilterData(value);
}
}
public ObservableCollection<DataItem> ParentItems { get; set; }
public DataItem SelectedParentItem { get; set; }
}
MainWindow.xaml
<Window>
<Window.DataContext>
<ViewModel />
</Window.DataContext>
<StackPanel>
<ListView ItemsSource="{Binding ParentItems}"
SelectedItem="{Binding SelectedParentItem}">
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}"/>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<TextBox Text="{Binding SearchPredicate, UpdateSourceTrigger=PropertyChanged}" />
<ListView ItemsSource="{Binding SelectedParentItem.ChildItems}" />
</StackPanel>
</Window>

Using the examples from #BionicCode- I added a SelectedParentItem INPC property to the ViewModel, performed the filtering on that via CollectionViewSource.Filter, and bound the ChildItems ListView to SelectedParentItem.ChildItems.
I did not bind the text box property changed to a backing field in the VM as per #BionicCode's example, as the "real" ChildItems might be in the mid 10,000's and I didn't want it to filter on each keystroke. So this answer implements the filter button and text box command, and the CanFilterChildren is doing a proper null check.
MainWindowViewModel.cs:
public class MainWindowViewModel : ViewModelBase
{
public ObservableCollection<ParentItem> ParentItems { get; set; }
private ParentItem _selectedParentItem;
public ParentItem SelectedParentItem
{
get { return _selectedParentItem; }
set { SetProperty(ref _selectedParentItem, value); }
}
public MainWindowViewModel()
{
ParentItems = new ObservableCollection<ParentItem>();
LoadDummyParentItems();
}
private ICommand _filterChildrenCommand;
public ICommand FilterChildrenCommand => _filterChildrenCommand ?? (_filterChildrenCommand = new RelayCommand(param => FilterChildren((string)param), param => CanFilterChildren((string)param)));
private bool CanFilterChildren(string filter) => SelectedParentItem != null && filter.Length > 0;
private void FilterChildren(string filter)
{
CollectionViewSource.GetDefaultView(SelectedParentItem.ChildItems).Filter = item => (item as string).Contains(filter);
}
private void LoadDummyParentItems()
{
for (var i = 0; i < 20; i++)
{
ParentItems.Add(new ParentItem()
{
Name = $"Parent Item {i}",
CreatedOn = DateTime.Now.AddHours(i),
IsActive = i % 2 == 0 ? true : false,
Status = i % 2 == 0 ? ParentItemStatus.Status_Two : ParentItemStatus.Status_One,
ChildItems = new List<string>() { $"Child one_{i}", $"Child two_{i}", $"Child three_{i}", $"Child four_{i}" }
});
}
}
}
MainWindow.xaml.cs:
public partial class MainWindow : Window
{
private readonly MainWindowViewModel _viewModel;
public MainWindow()
{
InitializeComponent();
_viewModel = new MainWindowViewModel();
this.DataContext = _viewModel;
}
}
MainWindow.xaml:
<Window x:Class="FilteringDemo.Views.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:FilteringDemo.Views"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width=".25*"/>
<ColumnDefinition Width=".75*"/>
</Grid.ColumnDefinitions>
<ListView x:Name="ItemList" Grid.Column="0" Margin="2" ItemsSource="{Binding ParentItems}" SelectedItem="{Binding SelectedParentItem, Mode=OneWayToSource}" SelectionMode="Single">
<ListView.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding Name}"/>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<Grid Grid.Column="1">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="1*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Grid Grid.Row="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="1*"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Column="0" Text="{Binding ElementName=ItemList, Path=SelectedItem.Name}" Margin="2"/>
<TextBlock Grid.Column="1" Text="{Binding ElementName=ItemList, Path=SelectedItem.CreatedOn}" Margin="2"/>
<TextBlock Grid.Column="2" Text="{Binding ElementName=ItemList, Path=SelectedItem.IsActive}" Margin="2"/>
<TextBlock Grid.Column="3" Text="{Binding ElementName=ItemList, Path=SelectedItem.Status}" Margin="2"/>
</Grid>
<ListView Grid.Row="1" Margin="2" ItemsSource="{Binding SelectedParentItem.ChildItems}" />
<Grid Grid.Row="2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="1*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<TextBox x:Name="ChildFilterInput" Grid.Column="0" Margin="2">
<TextBox.InputBindings>
<KeyBinding Command="{Binding FilterChildrenCommand}" CommandParameter="{Binding ElementName=ChildFilterInput, Path=Text}" Key="Return" />
</TextBox.InputBindings>
</TextBox>
<Button Grid.Column="1" Content="Filter" Width="100" Margin="2" Command="{Binding FilterChildrenCommand}" CommandParameter="{Binding ElementName=ChildFilterInput, Path=Text}"/>
</Grid>
</Grid>
</Grid>
</Window>
ViewModelBase.cs:
public abstract class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected bool SetProperty<T>(ref T field, T newValue, [CallerMemberName] string propertyName = null)
{
if (!EqualityComparer<T>.Default.Equals(field, newValue))
{
field = newValue;
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
return true;
}
return false;
}
}
RelayCommand.cs:
public class RelayCommand : ICommand
{
private Predicate<object> _canExecuteMethod;
private Action<object> _executeMethod;
public RelayCommand(Action<object> executeMethod, Predicate<object> canExecuteMethod = null)
{
_executeMethod = executeMethod;
_canExecuteMethod = canExecuteMethod;
}
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
public bool CanExecute(object parameter)
{
return _canExecuteMethod == null ? true : _canExecuteMethod(parameter);
}
public void Execute(object parameter)
{
_executeMethod(parameter);
}
}
ParentItem.cs:
public class ParentItem
{
public string Name { get; set; }
public List<string> ChildItems { get; set; }
public DateTime CreatedOn { get; set; }
public bool IsActive { get; set; }
public ParentItemStatus Status { get; set; }
}
public enum ParentItemStatus
{
Status_One,
Status_Two
}
App.xaml:
<Application x:Class="FilteringDemo.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:FilteringDemo"
StartupUri="Views/MainWindow.xaml">
<Application.Resources>
</Application.Resources>
</Application>
Note: The MainWindow.xaml file was moved into a "Views" folder, so I'm including the App.xaml with the updated StartupUri in case anyone is trying to copy and paste.

Comment section inside each ListBox items

I'm developing an external application in C#/WPF which display information : Name, Details. Etc...
I handle this part with a ListBox and simple Binding. I populate my ListBox this way :
model.ClassAs.Add(new ClassA { Name = textBox1.Text, Detail = textBox2.Text });
The problem come now : I now have to implement a Comment Section for users to add comments inside each ListBoxItems separately. Obviously I can't fill the Comment Section when i populate Name and Details. So i create a second ListBox inside the ItemsTemplate of the first one, a ListBoxSeption if you want. I create an other Class ClassB and try to implement the Binding like the first time.
Obviously that did not work because i was in the DataContext of ListBox1. I try to set up an ObservableCollection with a PropertyChanged Event but i can't get it to work. I don't understand this process very well so i don't see where my error is.
Here is my XAML:
<ListBox x:Name="listBox" MouseDoubleClick="ListBox_MouseDoubleClick"
ScrollViewer.HorizontalScrollBarVisibility="Disabled" HorizontalContentAlignment="Stretch"
ItemsSource="{Binding ClassAs, Mode=OneWay}" Grid.Column="1" >
<ListBox.ItemTemplate>
<DataTemplate>
<Grid x:Name="grd">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="100"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="auto"/>
</Grid.RowDefinitions>
<TextBlock Name="Name" Text="{Binding Name, Mode=OneWay}" Grid.Column="2" Foreground="DarkGray" FontWeight="Bold" />
<TextBlock Text="{Binding Detail, Mode=OneWay}" Grid.Column="2" Grid.Row="1" TextWrapping="Wrap" />
<Grid x:Name="comSection" Visibility="{Binding RelativeSource={RelativeSource AncestorType={x:Type ListBoxItem}}, Path=IsSelected, Converter={StaticResource booleanVisibleConverter}}"
Grid.Column="2" Grid.Row="2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<AdornerDecorator>
<TextBox x:Name="textBoxCom" HorizontalAlignment="Stretch"
TextWrapping="Wrap" Grid.Column="0" Grid.Row="0">
<controls:WatermarkService.Watermark>
<TextBlock>Type Comment Here...</TextBlock>
</controls:WatermarkService.Watermark>
</TextBox>
</AdornerDecorator>
<ListBox x:Name="listBoxCom" BorderThickness="0,0,0,0" Grid.Row="1" Grid.Column="0"
HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" VerticalAlignment="Stretch" ScrollViewer.VerticalScrollBarVisibility="Visible"
ItemsSource="{Binding ClassBs.Commentary}">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="20"/>
<RowDefinition Height="20"/>
</Grid.RowDefinitions>
<TextBlock Name="TBCom" Text="{Binding}"></TextBlock>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>
<Button x:Name="addComment" HorizontalAlignment="Center" VerticalAlignment="Top" Width="25" Height="25"
BorderThickness="0" Click="addComment_Click" Background="Transparent" Grid.Column="1" Grid.Row="2"
ToolTip="Comment">
<Button.Content>
<Image Source="Assets\plus_orange.png" />
</Button.Content>
</Button>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
What i want : The user fill textBoxCom and Press addComment Button to add a Comment in the selected ListBoxItem.
My Classes :
public sealed class ClassA : INotifyPropertyChanged
{
public string Name { get; set; }
public string Detail { get; set; }
public ObservableCollection<ClassB> ClassBs { get; set; }
public List<ClassB> ModifiedComments { get; set; }
public event PropertyChangedEventHandler PropertyChanged;
public class ClassB
{
string Commentary { get; set;}
}
}
My ViewModel :
public sealed class ViewModel
{
public ObservableCollection<ClassA> ClassAs { get; set; }
public ObservableCollection<ClassA.ClassB> ClassBs { get; set; }
List<ClassA.ClassB> ModifiedItems { get; set; }
public ViewModel()
{
ClassAs = new ObservableCollection<ClassA>();
CLassBs = new ObservableCollection<ClassA.ClassB>();
ModifiedItems = new List<ClassA.ClassB>();
this.ClassBs.CollectionChanged += this.OnCollectionChanged;
}
void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
try
{
if (e.NewItems != null)
{
foreach (ClassA.ClassB newItem in e.NewItems)
{
ModifiedItems.Add(newItem);
//Add listener for each item on PropertyChanged event
newItem.PropertyChanged += this.OnItemPropertyChanged;
}
}
if (e.OldItems != null)
{
foreach (ClassA.ClassB oldItem in e.OldItems)
{
ModifiedItems.Add(oldItem);
oldItem.PropertyChanged -= this.OnItemPropertyChanged;
}
}
}
catch(Exception ex)
{
MessageBox.Show("me : " + ex);
}
}
void OnItemPropertyChanged(object sender, PropertyChangedEventArgs e)
{
ClassA.ClassB item = sender as ClassA.ClassB;
if (item != null)
ModifiedItems.Add(item);
}
}
My Click Event (AddComment)
private void addComment_Click(object sender, RoutedEventArgs e)
{
try
{
currentSelectedListBoxItem = this.listBox.ItemContainerGenerator.ContainerFromIndex(listBox.SelectedIndex) as ListBoxItem;
System.Windows.Controls.TextBox textBoxCom = Helper.FindDescendant<System.Windows.Controls.TextBox>(currentSelectedListBoxItem);
ListBox LBCom = Helper.FindDescendant<ListBox>(currentSelectedListBoxItem);
if (string.IsNullOrWhiteSpace(textBoxCom.Text))
MessageBox.Show("Please fill the Comment Section");
else
{
model.ClassBs.Add(new ClassA.ClassB { Commentary = textBoxCom.Text });
textBoxCom.Clear();
}
}
catch (Exception exp)
{
MessageBox.Show("exp = " + exp);
}
}
Sorry for the very long post, i hope you can help my on this !

Well this was way simpler than expected, i was just digging in useless code!
I get rid of all the code about ObservableCollection and PropertyChange Event.
My final ClassA Code (no more ClassB) :
public sealed class ClassA
{
public string Name { get; set; }
public string Detail { get; set; }
public List<string> Comments { get; set; }
public Issue()
{
Comments = new List<string>();
}
}
And my final Click Event :
var selected = listBox.SelectedItem as ClassA;
selected.Comments.Add(textBoxCom.Text);
listBox.Items.Refresh();
textBoxCom.Clear();
Thank you #Sidewinder94 !

Having problems binding my datagrid to data from my database

i've a problem to use datagrid in wpf mvvm project
Here is my xaml :
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:dxe="http://schemas.devexpress.com/winfx/2008/xaml/editors"
x:Class="noteManager.MainWindow"
xmlns:vm="clr-namespace:noteManager.ViewModel"
DataContext="{StaticResource noteManagerViewModel}"
Title="NoteManager" Height="490" Width="525">
<Grid Margin="0,0,0,-132.5">
<Grid.RowDefinitions>
<RowDefinition Height="10"></RowDefinition>
<RowDefinition Height="50"></RowDefinition>
<RowDefinition Height="200"></RowDefinition>
<RowDefinition Height="40"></RowDefinition>
<RowDefinition Height="110"></RowDefinition>
<RowDefinition Height="111"></RowDefinition>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="10"></ColumnDefinition>
<ColumnDefinition Width="80"></ColumnDefinition>
<ColumnDefinition Width="100"></ColumnDefinition>
<ColumnDefinition Width="80"></ColumnDefinition>
<ColumnDefinition Width="100"></ColumnDefinition>
<ColumnDefinition Width="50"></ColumnDefinition>
<ColumnDefinition Width="50"></ColumnDefinition>
</Grid.ColumnDefinitions>
<TextBlock Text="Login :" FontSize="16" Grid.Column="2" Margin="51,9,50,0" Grid.RowSpan="2" Height="23" VerticalAlignment="Top" Grid.ColumnSpan="2"/>
<TextBox Text="{Binding Login}" Grid.Row="1" Grid.Column="3" Margin="14,0,86,29" Grid.ColumnSpan="2"/>
<Button Background="LightGreen" Foreground="Green" Command="{Binding testConnexion}" x:Name="testConnexion" Content="Connexion" Grid.Row="1" Grid.Column="2" Margin="51,29,86,0" Grid.ColumnSpan="3"/>
<Button Command="{Binding addUser}" Content="+" Grid.Row="1" Grid.Column="4" Margin="34,1,20,0" RenderTransformOrigin="0.742,0.468"/>
<DataGrid Name="dataGrid1" Grid.Row="2" Margin="8,7,-22,7" AutoGenerateColumns="False"
ItemsSource="{Binding _DataGridNotes}" SelectedItem="{Binding Path=MySelectedNote}" HorizontalAlignment="Center"
Width="480" Grid.ColumnSpan="6" Grid.Column="1">
<DataGrid.Columns>
<DataGridTextColumn Width="100" Binding="{Binding Path=NoteTitle}" Header="Titre" />
<DataGridTextColumn Width="200" Binding="{Binding Path=NoteContent}" Header="Note" />
<DataGridTextColumn Width="100" Binding="{Binding Path=NoteCreatedAt}" Header="Date de création" />
<DataGridTextColumn Width="100" Binding="{Binding Path=NoteUpdatedAt}" Header="Dat MAJ" />
</DataGrid.Columns>
</DataGrid>
<TextBlock Text="Titre" FontSize="16" Grid.Row="3" Grid.Column="1" Margin="27,8,7,1"/>
<TextBox Text="{Binding Path=titre, Mode=TwoWay}" Grid.Row="3" Grid.Column="2" Margin="17,10,23,10" Grid.ColumnSpan="5"/>
<TextBlock Text="Note" FontSize="16" Grid.Row="4" Grid.Column="1" Margin="27,4,7,0"/>
<TextBox Text="{Binding Path=description, Mode=TwoWay}" Grid.Row="4" Grid.Column="2" Margin="17,10,23,8" Grid.ColumnSpan="5"/>
<Button Command="{Binding Path=DeleteNote}" Background="LightPink" Foreground="red" Content="Supprimer" Grid.Row="5" Grid.Column="1" Margin="55,7,26,81" Grid.ColumnSpan="2"/>
<Button Command="{Binding Path=UpdateANote}" Content="Mettre à jour" Grid.Row="5" Grid.Column="3" Margin="14,7,67,81" Grid.ColumnSpan="2" RenderTransformOrigin="0.5,0.5"/>
<Button Command="{Binding Path=AddNote}" Content="Ajouter" Grid.Row="5" Grid.Column="4" Margin="78,7,10,81" Grid.ColumnSpan="3"/>
</Grid>
</Window>
Here is my viewModel :
namespace noteManager.ViewModel
{
public class noteManagerViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
void Notify(string property)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(property));
}
}
string login;
int currentUser;
public string Login
{
get
{
return login;
}
set
{
login = value; Notify("Login");
}
}
private bool _canExecute;
public noteManagerViewModel()
{
_canExecute = true;
}
private ICommand _testConnexion;
public ICommand testConnexion
{
get
{
return _testConnexion ?? (_testConnexion = new CommandHandler(() => Connexion(), _canExecute));
}
}
private ICommand _addUser;
public ICommand addUser
{
get
{
return _addUser ?? (_addUser = new CommandHandler(() => AjoutUser(), _canExecute));
}
}
private ObservableCollection<DataGridNotes> _DataGridNotes = new ObservableCollection<DataGridNotes>();
public ObservableCollection<DataGridNotes> dataGridNotes
{
// No need for a public setter
get { return _DataGridNotes; }
}
}
the other class that i use :
public class User
{
/*public User()
{
this.Note = new HashSet<Note>();
}*/
public int Id { get; set; }
public string Login { get; set; }
//public virtual ICollection<Note> Note { get; set; }
}
public class Note : INotifyPropertyChanged
{
public int Id { get; set; }
public string NoteText { get; set; }
public string ContentText { get; set; }
public DateTime CreatedAt { get; set; }
public DateTime? UpdatedAt { get; set; }
public int UserId { get; set; }
//public virtual User User { get; set; }
public event PropertyChangedEventHandler PropertyChanged;
public void Notify(string property)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(property));
}
}
}
public class DataGridNotes
{
private string _noteTitle;
private string _noteContent;
private string _noteCreatedAt;
private string _noteUpdatedAt;
public string NoteTitle { get { return _noteTitle; } set { _noteTitle = value; } }
public string NoteContent { get { return _noteContent; } set { _noteContent = value; } }
public string NoteCreatedAt { get { return _noteCreatedAt; } set { _noteCreatedAt = value; } }
public string NoteUpdatedAt { get { return _noteUpdatedAt; } set { _noteUpdatedAt = value; } }
}
sorry for the ugly code, new to c# for a project.
i want to use the datagrid in my viewmodel but don't find a way to make it work (would like to write data from mysql database in the datagrid
Have you an idea to make it work ?
thx in advance

Ok, It's tough to spot what you are doing wrong without seeing the ViewModel, however you may want to check the following:
1) The DataContext is correct.
2) The property _DataGridNotes exists. Check the program output to make sure that there are no warnings informing you that bindings are broken.
The property you are looking to have should look something like this:
List<Note> _DataGridNotes
{
get
{
// get notes from SQL request
// construct list of Note and return list
}
}
You should also make sure that the Note class contains the properties required (NoteTitle, NoteContent, NoteCreatedAt, NoteUpdatedAt).
It might also be worth passing back some dummy notes to debug if the problem lies in the request to the SQL database.

The problem is that you are trying to bind to a private Observable collection _DataGridNotes where you should be binding to the property dataGridNotes:
ItemsSource="{Binding dataGridNotes}"

Getting Values displayed in one method call XAML WPF

As the title says, im trying to display the hardcoded values I typed in my XAML file through databindings but in 1 method call instead of binding the textboxes in every specific property.
Model:
public class Person
{
public string Namn { get; set; }
public DateTime Födelsedatum { get; set; }
public int Betyg { get; set; }
public int AntalBarn { get; set; }
public int Favoritsiffra { get; set; }
public string Kommentar { get; set; }
}
View:
<Window x:Class="PiedPiper.View.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Inlämningsuppgift WPF" Height="400" Width="400">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Label Content="Personuppgifter" FontSize="35" Grid.Column="0" Grid.Row="0"></Label>
<Separator Grid.Column="0" Grid.Row="1" Grid.ColumnSpan="2" Margin="10,2,-50,2"/>
<Label Content="Namn:" Grid.Column="0" Grid.Row="2" Margin="5,5,210,0"></Label>
<TextBox Name="NamnTextBox" Grid.Row="2" Grid.Column="0" Grid.ColumnSpan="2" Margin="118,5,-50,0"/>
<Label Content="Födelsedatum:" Grid.Column="0" Grid.Row="3" Margin="5,5,210,0"></Label>
<TextBox Name="FödelsedatumTextBox" Grid.Row="3" Grid.Column="0" Grid.ColumnSpan="2" Margin="118,5,-50,0"></TextBox>
<Label Content="Betyg" Grid.Column="0" Grid.Row="4" Margin="5,5,210,0"></Label>
<ComboBox Name="BetygComboBox" Grid.Row="4" Grid.Column="0" Grid.ColumnSpan="2" Margin="218,5,-50,0"></ComboBox>
<Label Content="Antal barn (0-20):" Grid.Column="0" Grid.Row="5" Margin="5,5,210,0"></Label>
<Slider Grid.Row="5" Grid.Column="0" Grid.ColumnSpan="2" Margin="125,5,25,0"></Slider>
<TextBox Name="AntalBarnTextBox" Grid.Row="5" Grid.Column="0" Grid.ColumnSpan="2" Margin="300,5,-50,0"></TextBox>
<Label Content="Favoritsiffra (0-99):" Grid.Column="0" Grid.Row="6" Margin="5,5,210,0"></Label>
<TextBox Name="FavoritsiffraTextBox" Grid.Row="6" Grid.Column="0" Grid.ColumnSpan="2" Margin="225,5,-50,0"></TextBox>
<CheckBox Content="Visa kommentar" Grid.Row="7" Grid.Column="0" Margin="5,5,210,0"></CheckBox>
<TextBox Name="KommentarTextBox" Grid.Row="7" Grid.Column="0" Grid.ColumnSpan="2" Margin="125,5,-50,-50" Grid.RowSpan="2"></TextBox>
<Button Content="Spara" Grid.Row="8" Grid.Column="0" Margin="125,55,-50,-80" Grid.ColumnSpan="2"></Button>
<Separator Grid.Row="9" Grid.Column="0" Grid.ColumnSpan="2" Margin="10,85,-50,-80"></Separator>
<Label Content="Andre Kordasti" Grid.Row="10" Grid.Column="0" Margin="10,85,-50,-80"></Label>
<Button Content="Avsluta" Grid.Row="10" Grid.Column="0" Margin="225,85,-50,-80" Grid.ColumnSpan="2"></Button>
</Grid>
ViewModel:
public class PersonViewModel : INotifyPropertyChanged
{
public PersonViewModel(Person person)
{
Namn = person.Namn;
Födelsedatum = person.Födelsedatum;
Betyg = person.Betyg;
AntalBarn = person.AntalBarn;
Favoritsiffra = person.Favoritsiffra;
Kommentar = person.Kommentar;
GetPerson();
}
private void GetPerson()
{
Namn = "KurtSune";
Födelsedatum = new DateTime(1980, 09, 06);
Betyg = 3;
AntalBarn = 7;
Favoritsiffra = 10;
Kommentar = "Kommentar...";
var mainWindow = new MainWindow();
mainWindow.NamnTextBox.Text = Namn;
mainWindow.FödelsedatumTextBox.Text = Convert.ToString(Födelsedatum);
mainWindow.BetygComboBox.SelectedValue = Betyg;
mainWindow.AntalBarnTextBox.Text = Convert.ToString(AntalBarn);
mainWindow.FavoritsiffraTextBox.Text = Convert.ToString(Favoritsiffra);
mainWindow.KommentarTextBox.Text = Kommentar;
}
public ICommand SaveCommand { get; set; }
public ICommand AbortCommand { get; set; }
public bool CanSave
{
get
{
if (Namn == null)
{
return false;
}
return !String.IsNullOrWhiteSpace(Namn);
}
}
private string _namn;
public string Namn
{
get { return _namn; }
set { _namn = value; OnPropertyChanged("Namn"); }
}
private DateTime _födelsedatum;
public DateTime Födelsedatum
{
get { return _födelsedatum; }
set { _födelsedatum = value; OnPropertyChanged("Födelsedatum"); }
}
private int _betyg;
public int Betyg
{
get { return _betyg; }
set { _betyg = value; OnPropertyChanged("Betyg"); }
}
private int _antalBarn;
public int AntalBarn
{
get { return _antalBarn; }
set { _antalBarn = value; OnPropertyChanged("AntalBarn"); }
}
private int _favoritSiffra;
public int Favoritsiffra
{
get { return _favoritSiffra; }
set { _favoritSiffra = value; OnPropertyChanged("Födelsedatum"); }
}
private string _kommentar;
public string Kommentar
{
get { return _kommentar; }
set { _kommentar = value; OnPropertyChanged("Kommentar"); }
}
private void OnPropertyChanged(string propertyName)
{
var handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
public event PropertyChangedEventHandler PropertyChanged;
}
}
And to add my App.xaml.cs file:
public partial class App : Application
{
protected override void OnStartup(StartupEventArgs e)
{
base.OnStartup(e);
var person = new Person();
var personViewModel = new PersonViewModel(person);
var mainWindow = new MainWindow();
mainWindow.DataContext = personViewModel;
mainWindow.Show();
}
}
So I dont get the following values to be displayed... Please help, Iam new to this.

Here is a simplified example where,
I made a DataTemplate where controls are bound to the Person properties. Benefits are obvious because as you will see whichever end is modified, the other will know/show these changes.
(added a button and a MessageBox to further demonstrate this)
Code:
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows;
namespace WpfApplication1
{
public partial class MainWindow
{
public MainWindow()
{
InitializeComponent();
var person = new Person {Name = "name1", Address = "address1"};
person.PropertyChanged += person_PropertyChanged;
DataContext = person;
}
private void person_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
MessageBox.Show("data changed");
}
private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
{
var dataContext = (Person) DataContext;
dataContext.Name = "newName";
dataContext.Address = "newAddress";
}
}
internal class Person : INotifyPropertyChanged
{
private string _address;
private string _name;
public string Name
{
get { return _name; }
set
{
_name = value;
OnPropertyChanged();
}
}
public string Address
{
get { return _address; }
set
{
_address = value;
OnPropertyChanged();
}
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
XAML:
<Window x:Class="WpfApplication1.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:wpfApplication1="clr-namespace:WpfApplication1"
Title="MainWindow"
Width="525"
Height="350">
<Window.Resources>
<DataTemplate x:Key="PersonTemplate" DataType="wpfApplication1:Person">
<StackPanel>
<TextBlock Text="Name" />
<TextBox Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}" />
<TextBlock Text="Address" />
<TextBox Text="{Binding Address, UpdateSourceTrigger=PropertyChanged}" />
</StackPanel>
</DataTemplate>
</Window.Resources>
<Grid>
<StackPanel>
<Button Click="ButtonBase_OnClick" Content="Modify" />
<ContentControl Content="{Binding}" ContentTemplate="{StaticResource PersonTemplate}" />
</StackPanel>
</Grid>
</Window>
Now as you can see there are no hard-coded values in XAML, the object I have passed to DataContext has sample values instead.

Having problems with WPF Databinding

I have 2 objects, a Customer and a Store. There are multiple store locations, each customer has a property called PreferredStoreId (int?) which relates to a Store's Id (int).
In a WPF application I am attempting to build a form that allows a customer to be edited. A combo box exists on this form which is filled with Stores to act as a way of displaying the currently set PreferredStore and a way of changing the preferred store.
My problem is, whilst I can populate the combobox, I cannot get two way binding between the Customer.PreferredId (the object set to the UserControl's datacontext) and the combobox's SelectedItem (a Store Object)'s .Id property.
Here Is my XAML to help make sense:
<UserControl x:Class="ucCustomerEditor"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:localViewModels="clr-namespace:ViewModels"
xmlns:qc="clr-namespace:QuickConverter;assembly=QuickConverter"
mc:Ignorable="d" d:DesignWidth="750" Height="334">
<UserControl.DataContext>
<localViewModels:CustomerViewModel x:Name="customerViewModel" />
</UserControl.DataContext>
<StackPanel>
<StackPanel Orientation="Horizontal" HorizontalAlignment="Right">
<Button Height="26" Width="50" Content="Save" Margin="5,10" Click="UserAction_Save" />
<Button Height="26" Width="50" Content="Cancel" Margin="10,10" Click="UserAction_Cancel" />
</StackPanel>
<Grid Height="26" Margin="10" VerticalAlignment="Top">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="209"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBox Text="{Binding FirstName}" Height="23" Margin="10,0,0,0" TextWrapping="Wrap" VerticalAlignment="Top" HorizontalAlignment="Stretch" Grid.Column="1"/>
<Label Content="First Name:" Margin="10,0" VerticalAlignment="Top" FontWeight="Bold"/>
</Grid>
<Grid Height="26" Margin="10" VerticalAlignment="Top">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="209"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBox Text="{Binding LastName}" Height="23" Margin="10,0,0,0" TextWrapping="Wrap" VerticalAlignment="Top" HorizontalAlignment="Stretch" Grid.Column="1"/>
<Label Content="Last Name:" Margin="10,0" VerticalAlignment="Top" FontWeight="Bold"/>
</Grid>
<Grid Height="26" Margin="10" VerticalAlignment="Top">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="209"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBox Text="{Binding EmailAddress}" Height="23" Margin="10,0,0,0" TextWrapping="Wrap" VerticalAlignment="Top" HorizontalAlignment="Stretch" Grid.Column="1"/>
<Label Content="Email Address:" Margin="10,0" VerticalAlignment="Top" FontWeight="Bold"/>
</Grid>
<Grid Height="26" Margin="10" VerticalAlignment="Top">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="209"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBox Text="{Binding PhoneNumber}" Height="23" Margin="10,0,0,0" TextWrapping="Wrap" VerticalAlignment="Top" HorizontalAlignment="Stretch" Grid.Column="1"/>
<Label Content="Phone Number:" Margin="10,0" VerticalAlignment="Top" FontWeight="Bold"/>
</Grid>
<Grid Height="26" Margin="10" VerticalAlignment="Top">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="209"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<ComboBox Name="cbPreferredStore"
ItemsSource="{Binding Stores}" DisplayMemberPath="DisplayName" Height="23" Margin="10,0,0,0" VerticalAlignment="Top"
HorizontalAlignment="Stretch" Grid.Column="1" SelectedValue="{Binding ElementName=customerViewModel, Path=PreferredStoreId}">
<ComboBox.DataContext>
<localViewModels:StoreListViewModel />
</ComboBox.DataContext>
</ComboBox>
<Label Content="Preferred Store:" Margin="10,0" VerticalAlignment="Top" FontWeight="Bold"/>
</Grid>
<Grid Height="26" Margin="10" VerticalAlignment="Top">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="209"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBox Text="{Binding Password}" Height="23" Margin="10,0,0,0" TextWrapping="Wrap" VerticalAlignment="Top" HorizontalAlignment="Stretch" Grid.Column="1"/>
<Label Content="Password:" Margin="10,0" VerticalAlignment="Top" Height="26" FontWeight="Bold"/>
</Grid>
</StackPanel>
StoreViewModel code:
ublic class StoreViewModel : BaseViewModel
{
private enum Modes { CREATE, UPDATE }
private Modes _mode;
private Store _store;
public string DisplayName
{
get { return string.Format("{0} ({1})", this._store.LocationName, this._store.Id); }
}
public int Id
{
get { return this._store.Id; }
set
{
this._store.Id = value;
notifyPropertyChanged("Id");
notifyPropertyChanged("DisplayName");
}
}
public string LocationName
{
get { return this._store.LocationName; }
set
{
this._store.LocationName = value;
notifyPropertyChanged("LocationName");
notifyPropertyChanged("DisplayName");
}
}
public string ImageURL
{
get { return this._store.ImageURL; }
set
{
this._store.ImageURL = value;
notifyPropertyChanged("ImageURL");
}
}
public string AddressLine1
{
get { return this._store.AddressLine1; }
set
{
this._store.AddressLine1 = value;
notifyPropertyChanged("AddressLine1");
}
}
public string AddressLine2
{
get { return this._store.AddressLine2; }
set
{
this._store.AddressLine2 = value;
notifyPropertyChanged("AddressLine2");
}
}
public string AddressLine3
{
get { return this._store.AddressLine3; }
set
{
this._store.AddressLine3 = value;
notifyPropertyChanged("AddressLine3");
}
}
public string Suburb
{
get { return this._store.Suburb; }
set
{
this._store.Suburb = value;
notifyPropertyChanged("Suburb");
}
}
public string State
{
get { return this._store.State; }
set
{
this._store.State = value;
notifyPropertyChanged("State");
}
}
public string Postcode
{
get { return this._store.Postcode; }
set
{
this._store.Postcode = value;
notifyPropertyChanged("Postcode");
}
}
public string Country
{
get { return this._store.Country; }
set
{
this._store.Country = value;
notifyPropertyChanged("Country");
}
}
public string PhoneNumber
{
get { return this._store.PhoneNumber; }
set
{
this._store.PhoneNumber = value;
notifyPropertyChanged("PhoneNumber");
}
}
public string EmailAddress
{
get { return this._store.EmailAddress; }
set
{
this._store.EmailAddress = value;
notifyPropertyChanged("EmailAddress");
}
}
public static explicit operator StoreViewModel(EasyDayTea.Store store)
{
return new StoreViewModel(store) { _mode = Modes.UPDATE };
}
public StoreViewModel()
{
_store = new Store();
_mode = Modes.CREATE;
}
public StoreViewModel(Store store)
{
_store = store;
_mode = Modes.UPDATE;
}
public void Cancel()
{
if (_mode == Modes.CREATE)
{
_store = new Store() { };
}
else
{
EasyDayTea.EasyDayTeaClient client = new EasyDayTeaClient();
_store = client.FetchStore(App.AppUserTeaCredental, _store.Id);
client.Close();
}
notifyAll();
}
public void Save()
{
try
{
EasyDayTeaClient client = new EasyDayTeaClient();
if (_mode == Modes.CREATE)
{
client.AddStore(App.AppUserTeaCredental, ImageURL, LocationName, AddressLine1, AddressLine2, AddressLine3, Suburb, State, Postcode, Country, PhoneNumber, EmailAddress);
}
else
{
client.SetStore(App.AppUserTeaCredental, Id, ImageURL, LocationName, AddressLine1, AddressLine2, AddressLine3, Suburb, State, Postcode, Country, PhoneNumber, EmailAddress);
}
client.Close();
MessageBox.Show("Your customer was saved.");
if (_mode == Modes.CREATE)
{
_store = new Store();
notifyAll();
}
else
{
//do nothing.
}
}
catch (Exception ex)
{
MessageBox.Show("There was a problem saving your customer: \r\n" + ex.Message);
}
}
internal void notifyAll()
{
notifyPropertyChanged("Id");
notifyPropertyChanged("LocationName");
notifyPropertyChanged("ImageURL");
notifyPropertyChanged("AddressLine1");
notifyPropertyChanged("AddressLine2");
notifyPropertyChanged("AddressLine3");
notifyPropertyChanged("Suburb");
notifyPropertyChanged("State");
notifyPropertyChanged("Postcode");
notifyPropertyChanged("Country");
notifyPropertyChanged("PhoneNumber");
notifyPropertyChanged("EmailAddress");
notifyPropertyChanged("DisplayName");
}
}
StoreListViewModel Code:
public class StoreListViewModel : BaseViewModel
{
private List<StoreViewModel> _stores;
public List<StoreViewModel> Stores
{
get { return this._stores; }
set
{
this._stores = value;
notifyPropertyChanged("Stores");
}
}
public StoreListViewModel()
{
EasyDayTea.EasyDayTeaClient client = new EasyDayTea.EasyDayTeaClient();
_stores = client.GetStores(App.AppUserTeaCredental).Select(s => (StoreViewModel)s).ToList();
client.Close();
}
}

I suppose that PreferredStoreId property in CustomerViewModel correctly implement the INotifyPropertyChanged interface.
If it's true, then you need change the SelectedValue to SelectedItem of your ComboBox, because SelectedItem property returns the entire object which it current selected. However, the SelectedValuePath property and the SelectedValue uses together as an alternative to the SelectedItem property and as I understand it was not your choice.
Also here:
SelectedValue="{Binding ElementName=customerViewModel, Path=PreferredStoreId}"
Not need ElementName, because a CustomerViewModel set the DataContext assigned by default.