Login on WPF using MVVM

<page x:class="WolfswoodInCinch.Login" xmlns:x="#unknown">
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:CinchV2="clr-namespace:Cinch;assembly=Cinch.WPF"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
      xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
      mc:Ignorable="d" 
      d:DesignHeight="300" d:DesignWidth="300"
	 xmlns:views="clr-namespace:WolfswoodInCinch.Views"
        Title="Wolfswood Coach Booking System" Height="350" Width="525"
        xmlns:meffed="http:\\www.codeplex.com\MEFedMVVM"
        meffed:ViewModelLocator.ViewModel="LoginViewModel">

    <grid height="193" width="236">
        <label content="Wolfswood Coach Booking Application" height="28" horizontalalignment="Left" margin="10,10,0,0" name="label1" verticalalignment="Top" />
        <label content="Login" height="28" horizontalalignment="Left" margin="10,31,0,0" name="label2" verticalalignment="Top" />
        <textblock text="{Binding Path=Error, Mode=TwoWay}" foreground="Red"></textblock>
        <label content="Username: " height="28" horizontalalignment="Left" margin="10,78,0,0" name="label3" verticalalignment="Top" />
        <label content="Password: " height="28" horizontalalignment="Left" margin="10,112,0,0" name="label4" verticalalignment="Top" />

        <textbox height="23" horizontalalignment="Left" margin="82,83,0,0" name="textBox1" verticalalignment="Top" width="120" text="{Binding UserName.DataValue, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}">
            <i:interaction.behaviors xmlns:i="#unknown">
                <cinchv2:textboxfocusbehavior isusingdatawrappers="True" xmlns:cinchv2="#unknown" />
                <cinchv2:textboxfocusbehavior xmlns:cinchv2="#unknown" />
            </i:interaction.behaviors>
        </textbox>

        <textbox height="23" horizontalalignment="Left" margin="82,117,0,0" name="passwordBox1" verticalalignment="Top" width="120" text="{Binding Password.DataValue, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True, ValidatesOnExceptions=True}">
            <i:interaction.behaviors xmlns:i="#unknown">
                <cinchv2:textboxfocusbehavior isusingdatawrappers="True" xmlns:cinchv2="#unknown" />
                <cinchv2:textboxfocusbehavior xmlns:cinchv2="#unknown" />
            </i:interaction.behaviors>
        </textbox>

        <button content="Login" isdefault="True" height="23" horizontalalignment="Left" margin="149,158,0,0" name="button1" command="{Binding LoginViewFiredCommand}" verticalalignment="Top" width="75" click="button1_Click">
        </button>
        <textblock text="{Binding Path=loginResult}" horizontalalignment="Left" margin="12,146,0,12" name="textBlock1" width="131" />
    </grid>
</page>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Input;
using System.ComponentModel;
using WolfswoodInCinch.Views;
using WolfswoodInCinch.Classes;
using WolfswoodInCinch.Commands;
using MEFedMVVM.ViewModelLocator;
using Cinch;
using System.ComponentModel.Composition;
using System.Windows.Navigation;


namespace WolfswoodInCinch.ViewModels
{
    [ExportViewModel("LoginViewModel")]
    [PartCreationPolicy(CreationPolicy.NonShared)]
    public class LoginViewModel : ViewModelBase
    {
        private DataWrapper<string> userName;
        private DataWrapper<string> password;
        private IEnumerable<datawrapperbase> cachedListOfDataWrappers;
        //public IUIVisualizerService uiVisualizer;

        public LoginWindow Parent { get; set; }

        [ImportingConstructor]
        public LoginViewModel(/*IUIVisualizerService uiVisualizer*/)
        {
            UserName = new DataWrapper<string>(this, userNameChangeArgs);
            UserName.IsEditable = true;

            Password = new DataWrapper<string>(this, passwordChangeArgs);
            Password.IsEditable = true;

            cachedListOfDataWrappers = DataWrapperHelper.GetWrapperProperties<loginviewmodel>(this);


            //this.uiVisualizer = uiVisualizer;
            LoginViewFiredCommand = new SimpleCommand<object,>(ExecuteLoginCommand);
        }
  
        /// <summary>
        /// Username
        /// </summary>
        /// 
        static PropertyChangedEventArgs userNameChangeArgs = ObservableHelper.CreateArgs<loginviewmodel>(y => y.UserName);

        public DataWrapper<string> UserName
        {
            get { return userName; }
            private set
            {
                userName = value;
                NotifyPropertyChanged(userNameChangeArgs);
            }
        }

        /// <summary>
        /// Password
        /// </summary>
        static PropertyChangedEventArgs passwordChangeArgs = ObservableHelper.CreateArgs<loginviewmodel>(x => x.Password);

        public DataWrapper<string> Password
        {
            get { return password; }
            private set
            {
                password = value;
                NotifyPropertyChanged(passwordChangeArgs);
            }
        }

        public SimpleCommand<object,> LoginViewFiredCommand { get; private set; }

        private void ExecuteLoginCommand(EventToCommandArgs args)
        {
            
            string username = UserName.DataValue;
            string password = Password.DataValue;

            loginResult = "Successful login";

            //((LoginWindow)args.Sender).DialogResult = true;

            
            //Home home = new Home();
            //Welcome welcome = new Welcome();
            //welcome.Visibility.Equals(true);
            //Welcome main = new Welcome();
            //this.
            //this.Close();
            //WorkspaceData workspace = new WorkspaceData(
            //Views.Add(home);
            //NavigationService.GetNavigationService(this).Navigate(home);
        }

        string result;

        public string loginResult
        {
            get { return result; }
            set
            {
                result = value;
                NotifyPropertyChanged(_loginResultChangeArgs);
            }
        }

        static PropertyChangedEventArgs _loginResultChangeArgs = ObservableHelper.CreateArgs<loginviewmodel>(x => x.loginResult);

    }
}

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