Filter Collection MVVM

Question

Hello I'm trying to figure out the best way to filter a collection in MVVM using button Command. Here is the code. No errors are showing so I know I'm missing something. I able to populate the listbox but the filtering don't fire. using System; using System.Collections.Generic; using System.Linq; using System.Text; using DK_Project.Model; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Collections.ObjectModel; using System.Windows.Input; using System.Windows.Data; using System.Collections; using System.ComponentModel; namespace DK_Project.ViewModels { internal class EmployeeViewModel1:INotifyPropertyChanged { public EmployeeModel Employee { get ; set ; } ObservableCollection Employees = new ObservableCollection (); public EmployeeViewModel1() { Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Becky  LastName= Friedman  ContactTitle= LineCook  EmpImage= /Resources/EmployeImages/Becky.jpg  StDate= November 5 2003  EmpId= 1011  Rating= 5  WorkGroup= Broiler Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Bob  LastName= Broderick  ContactTitle= LineCook  EmpImage= /Resources/EmployeImages/Bob.jpg  StDate= November 4 2003  EmpId= 1012  Rating= 5  WorkGroup= Broiler Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Eric  LastName= Clapton  ContactTitle= Manager  EmpImage= /Resources/EmployeImages/Bubba.jpg  StDate= November4 2003  EmpId= 1013  Rating= 5  WorkGroup= Saute Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Jesus  LastName= Weinman  ContactTitle= LineCook  EmpImage= /Resources/EmployeImages/Jesus.jpg  StDate= November 9 2003  EmpId= 1014  Rating= 5  WorkGroup= Saute Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Steve  LastName= Vai  ContactTitle= LineCook  EmpImage= /Resources/EmployeImages/FOH1.jpg  StDate= November 9 2003  EmpId= 1015  Rating= 5  WorkGroup= Manager }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Jeff  LastName= Bonamassa  ContactTitle= LineCook  EmpImage= /Resources/EmployeImages/SousChef1.jpg  StDate= November 5 2003  EmpId= 1016  Rating= 5  WorkGroup= Manager }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Chef   LastName= Gates  ContactTitle= Chef  EmpImage= /Resources/EmployeImages/Chef1.jpg  StDate= November 5 2003  EmpId= 1017  Rating= 5  WorkGroup= Manager }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Mike  LastName= Anastasio  ContactTitle= SousChef  EmpImage= /Resources/EmployeImages/Mike.jpg  StDate= November 5 2003  EmpId= 1018  Rating= 5  WorkGroup= Saute Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Markus  LastName= Lommis  ContactTitle= SousChef  EmpImage= /Resources/EmployeImages/Markus.jpg  StDate= November 5 2003  EmpId= 1019  Rating= 5  WorkGroup= Pantry Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Bubba  LastName= Paisly  ContactTitle= AM Supervisor  EmpImage= /Resources/EmployeImages/Bubba.jpg  StDate= November 5 2003  EmpId= 1020  Rating= 5  WorkGroup= Pantry Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Sara  LastName= Gilbert  ContactTitle= PM Supervisor  EmpImage= /Resources/EmployeImages/Sara.jpg  StDate= November 5 2003  EmpId= 1021  Rating= 5  WorkGroup=  Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Samuel  LastName= Vaughn  ContactTitle= PrepCook  EmpImage= /Resources/EmployeImages/Samuel.jpg  StDate= November 5 2003  EmpId= 1031  Rating= 5  WorkGroup= Broiler Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Sara  LastName= Malmsteen  ContactTitle= PrepCook  EmpImage= /Resources/EmployeImages/sara.jpg  StDate= November 5 2003  EmpId= 1041  Rating= 5  WorkGroup= Broiler Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Zakk  LastName= Satriani  ContactTitle= PrepCook  EmpImage= /Resources/EmployeImages/SousChef2.jpg  StDate= November 5 2003  EmpId= 1051  Rating= 5  WorkGroup= Manager }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Clara  LastName= Rhoads  ContactTitle= PrepCook  EmpImage= /Resources/EmployeImages/Clara.jpg  StDate= November 5 2003  EmpId= 1061  Rating= 5  WorkGroup= Fry Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Susie  LastName= Meola  ContactTitle= LineCook  EmpImage= /Resources/EmployeImages/Susie.jpg  StDate= November 5 2003  EmpId= 1071  Rating= 5  WorkGroup= Fry Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Ted  LastName= Hendrix  ContactTitle= LineCook  EmpImage= /Resources/EmployeImages/Ted.jpg  StDate= November 5 2003  EmpId= 1081  Rating= 5  WorkGroup= Prep Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Ron  LastName= Lee  ContactTitle= DishWasher  EmpImage= /Resources/EmployeImages/Ron.jpg  StDate= November 5 2003  EmpId= 1091  Rating= 5  WorkGroup= Prep Cook }); Employees.Add( new EmployeeModel() { CompanyName= Digital Kitchen  Location= Eden Prairie  FirstName= Linda  LastName= Johnson  ContactTitle= DishWasher  EmpImage= /Resources/EmployeImages/Linda.jpg  StDate= November 5 2003  EmpId= 1101  Rating= 5  WorkGroup= Prep Cook }); } public ObservableCollection EmployeeList { get { return Employees; } } private MyCommand _filterCommand; public MyCommand FilterCommand { get { return _filterCommand; } set { _filterCommand = value; OnPropertyChanged( FilterCommand ); } } private void InitializeCommands() { FilterCommand = new MyCommand(FilterWorkGroup); } private void FilterWorkGroup() { this .GetListCollectionView().Filter = this .FilterWG; } private bool FilterWG( object obj) { if (obj as EmployeeModel != null && (obj as EmployeeModel).WorkGroup == Broiler Cook ) { return true ; } return false ; } private ListCollectionView GetListCollectionView() { return (ListCollectionView)CollectionViewSource.GetDefaultView( this .EmployeeList); } #region INotifyPropertyChanged Members public event PropertyChangedEventHandler PropertyChanged; public void OnPropertyChanged( string propertyName) { if (PropertyChanged != null ) PropertyChanged( this  new PropertyChangedEventArgs(propertyName)); } #endregion } public class MyCommand : ICommand { Action _action; public MyCommand(Action action) { _action = action; } #region ICommand Members public bool CanExecute( object parameter) { return true ; } public event EventHandler CanExecuteChanged; public void Execute( object parameter) { _action.Invoke(); } #endregion } } and in the xaml: Reagrds Rick

Tobias · Answer

Hi Rick Just some hints: - you should bind your ListBox to the ListCollectionView - you bind the Button-Command to a private property of your Filter instead your should bind it to the command (Command={Binding FilterCommand}) - you never call InitializeCommands() Greets Tobias

Sam Hobbs · Answer

I don't see try/catch blocks and things like that; isn't it posible that there are errors you are not aware of?