public abstract class ViewModelBase : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    protected void RaisePropertyChanged(string property)
    {
        if (PropertyChanged == null)
            return;
        PropertyChanged(this,
            new PropertyChangedEventArgs(property));
        PropertyChanged(this,

public class DelegateCommand : ICommand
{
    private readonly Predicate<object> _canExecute;
    private readonly Action<object> _execute;
 
    public event EventHandler CanExecuteChanged;
 
    public DelegateCommand(Action<object> execute) 
                   : this(execute, null)
    {

//Calling Code for VM to pass message box delegate
Func<string, string, MessageBoxButton, MessageBoxImage, MessageBoxResult> messageBox = (msg, caption, buttons, image) => MessageBox.Show(msg, caption, buttons, image);
 
//pass above variable to VM
 
//Usage of message box delegate variable inside VM
MessageBoxResult = messageBoxinVM("Test Message", "Test Caption for Message", MessageBoxButton.YesNoCancel, MessageBoxImage.Question);

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Windows.Data;
 
namespace VMLocatorSample.ViewModels
{
    public class ViewModelLocator