WPF_Practice/PacticeSolution/CommandPatternSample/ViewModel/EmpViewModel.cs

using CommandPatternSample.Command;
using CommandPatternSample.Model;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading.Tasks;

namespace CommandPatternSample.ViewModel
{
    internal class EmpViewModel : INotifyPropertyChanged
    {
        private Emp _selectedEmp;
        private ObservableCollection<Emp> _emps;

        public event PropertyChangedEventHandler PropertyChanged;

        public RelayCommand AddEmpCommand { get; set; }


        public EmpViewModel()
        {
            this.Emps = new ObservableCollection<Emp>();
            this.Emps.Add(new Emp() { Name = "Tom", Job = "Sales" });
            this.Emps.Add(new Emp() { Name = "Jack", Job = "Clerk" });
            this.Emps.Add(new Emp() { Name = "Phinix", Job = "Manager" });
            this.Emps.Add(new Emp() { Name = "John", Job = "Sales" });
            this.Emps.Add(new Emp() { Name = "Richard", Job = "Cleaning" });

            this.AddEmpCommand = new RelayCommand(new Action<object>(AddEmp));
        }

        public Emp SelectedEmp
        {
            get { return _selectedEmp; }
            set
            {
                _selectedEmp = value;
                this.OnPropertyChanged(nameof(SelectedEmp));
            }
        }

        public ObservableCollection<Emp> Emps
        {
            get { return _emps; }
            set
            {
                _emps = value;
                this.OnPropertyChanged(nameof(Emps));
            }
        }

        public void AddEmp(object param)
        {
            if (string.IsNullOrEmpty(param.ToString()))
                return;

            this.Emps.Add(new Emp { Name = param.ToString(), Job = "New Job" });
        }

        private void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            if (this.PropertyChanged == null)
                return;

            this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}