Tukukkk

I'm new to MVVM and WPF. Please suggest whether this is okay or I need to correct my understanding of MVVM which I confess is very limited as at the moment.

I have created a simple addition application which gets two number as input and provide the added number after clicking the Button.

Please give me your honest (and brutal) opinion, since that will help me improve the most.

Model.cs:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.ComponentModel;



namespace addition.Model

{

    class Number

    {

  public int number1



           { get; set; }





  public int number2

        { get; set; }



  public int number3

        { get; set; }





    }

}

ViewModel.cs

using addition.Model;



using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.ComponentModel;

using System.Collections.ObjectModel;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Input;





namespace addition.ViewModel

{

    class ViewModel : INotifyPropertyChanged

    {

        private Number n1 = new Number();

        int num, num1;





        public RelayCommand AddNew { get; set; }



       private string _number1;



public string FirstArgument

{



    get { return this._number1; }

    set

    {

        this._number1 = value;

        if (int.TryParse(_number1.ToString(), out num))

        {

            this.n1.number1 = num;

            this.OnPropertyChanged("FirstArgument");



        }

        else { MessageBox.Show("The given Value is not a Number "); }



    }

}

private string _number2;



        public string secondargument

        {

            get { return this._number2; }



            set

            {

                this._number2 = value;

                if (int.TryParse(_number2.ToString(), out num1))

                {

                    this.n1.number2 = num1;

                    this.OnPropertyChanged("secondargument");

                }

                else { MessageBox.Show("The given Value is not a Number "); }



            }

        }



        private string _number3;



        public string Addedargument

        {

            get { return this._number3; }

            set

            {

                this._number3 = value;

                this.OnPropertyChanged("Addedargument");

            }

        }



        public  ViewModel()

    {



        AddNew = new RelayCommand(o => AddNumbers());



    }





    private void AddNumbers()

    {

        var a = this.FirstArgument;

        var b = this.secondargument ;

    var c = (Convert.ToInt32(a) + Convert.ToInt32(b)).ToString();

    MessageBox.Show(c);

    Addedargument = c;





    }



    #region INotifyPropertyChanged Members



    public event PropertyChangedEventHandler PropertyChanged;

    private void OnPropertyChanged(string propertyName)

    {

        if (PropertyChanged != null)

        {

            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));

        }

    }

    #endregion



    }

}

View.xaml

<Window x:Class="addition.Window1"

         xmlns:vm="clr-namespace:addition.ViewModel" 

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

    Title="Window1" Height="300" Width="300">

    <Window.DataContext>

        <vm:ViewModel />

    </Window.DataContext>

    <Grid>



        <Label Height="28" Margin="28,54,0,0" Name="Number1" VerticalAlignment="Top" HorizontalAlignment="Left" Width="48">Number</Label>

        <TextBox Height="28" Margin="112,56,46,0"  Text ="{Binding Path = FirstArgument}"   Name="textBox1" VerticalAlignment="Top" />

        <Label Margin="28,106,0,128" Name="Number2" Width="58" HorizontalAlignment="Left">Number1</Label>

        <TextBox Height="28" Margin="112,120,46,120" Text ="{Binding  Path = secondargument}" Name="textBox2" />

        <Label Height="28" Margin="28,0,0,75" Name="label1" VerticalAlignment="Bottom" HorizontalAlignment="Left" Width="58">Number2</Label>

        <TextBox Height="23" Margin="112,0,46,68" Name="textBox3" Text="{Binding Path = Addedargument}" VerticalAlignment="Bottom" />

        <Button Height="23"  HorizontalAlignment="Left" Margin="39,0,0,16" Name="button1" VerticalAlignment="Bottom" Width="75" Command="{Binding AddNew}">Button</Button>

    </Grid>

</Window>