RelayCommand's reference is not found
c#, command, mvvm, relaycommand, wpf
Solution
RelayCommand is a class created by MS for handling event or command in WPF. you can create own class or go through below link.
http://msdn.microsoft.com/en-us/magazine/dd419663.aspx
Problem
I have a WPF application in which i'd like to change its design pattern to `MVVM`.I have used this snippet ``` using System; using System.Collections.Generic; using System.Linq; using System.Text; using FirstMVVm.Model; using System.ComponentModel; using System.Windows.Input; using System.Windows; namespace FirstMVVm.ModelView { class MyViewModel: INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged; private float result; public float Result { get { return result; } private set { if (result != value) { result = value; if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs("Result")); } } } } public int Number { get; set; } private RelayCommand _calculatePerimeterCommand; public ICommand CalculatePerimeterCommand { get { if (_calculatePerimeterCommand == null) { _calculatePerimeterCommand = new RelayCommand(param => this.CalculatePerimeter()); } return _calculatePerimeterCommand; } } private MyModel _model; public MyViewModel() { _model = new MyModel(); } private void CalculatePerimeter(){ Result = _model.Perimetre(Number); } } } ``` The problem is that the `RelayCommand` type is not known and i don't know what is the assembly missing. - So how can i fix this problem? Thanks,