INotifyPropertyChanged Event is not raising - wpf

Question

I had a Model class named as FormModel.cs while coding WPF using C#..
Below is my code. I am clueless that even though debugger is going into setter method of Name, PropertyChanged flag is not raising.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Windows;
namespace MVVM.Models
{
public class FormModel : INotifyPropertyChanged
{
private string _name;
public FormModel()
{
_name = "";
_bColor = "";
_fColor = "";
}
public string Name
{
get { return _name; }
set
{
_name = value;
NotifyPropertyChanged("Name");
}
}
private string _bColor;
public string BColor
{
get { return _bColor; }
set { _bColor = "RED"; }
}
private string _fColor;
public string FColor
{
get { return _fColor; }
set { _fColor = "BLUE"; }
}
public void apply(string Name, string BColor, string FColor)
{
this.Name = Name;
this.BColor = BColor;
this.FColor = FColor;
}
public event PropertyChangedEventHandler PropertyChanged;
public void NotifyPropertyChanged(string propName)
{
if(this.PropertyChanged!=null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propName));
if(propName=="Name")
{
MessageBox.Show("Hi" + Name);
}
}
}
}
}
Here are remaining Files I edited in question in quest on request
MainViewModel.cs
using MVVM.Models;
using MVVM.Views;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.ObjectModel;
using System.Windows.Input;
using System.Windows;
namespace MVVM.ViewModels
{
public class MainViewModel : ViewModelBase
{
private FormModel FModel;
private ICommand refresh;
public ICommand Refresh
{
get { return refresh; }
set { refresh = value; }
}
public MainViewModel()
{
FModel = new FormModel();
string s = "Pratik";
object o=(object)s;
refresh = new RelayCommand(new Action<object>(getGreet));
}
public void getGreet(object s1)
{
FModel.apply("dsf", "sf", "sf");
MessageBox.Show(s1.ToString());
}
private string _name;
public string Name
{
get { return _name; }
set {
_name = value;
FModel.Name = value;
}
}
}
class RelayCommand : ICommand
{
private Action<object> _action;
public RelayCommand(Action<object> action)
{
_action = action;
}
public bool CanExecute(object parameter)
{
return true;
}
public event EventHandler CanExecuteChanged;
public void Execute(object parameter)
{
_action(parameter);
}
}
}
ViewModelBase.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
namespace MVVM.ViewModels
{
public abstract class ViewModelBase: INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if(handler!=null)
{
if (propertyName == "Name")
{
//Command
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
}
Below are View Files
MainView.xaml
<Window x:Class="MVVM.Views.MainView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:VM="clr-namespace:MVVM.ViewModels"
Title="UI" Height="300" Width="300">
<Grid Background="RED">
<TextBox Name="TT" TextWrapping="Wrap" Text="{Binding Name}" Margin="20,15,160,225" />
<TextBox TextWrapping="Wrap" Text="Back Color" Margin="20,73,195,167" />
<TextBox TextWrapping="Wrap" Text="Font Color" Margin="20,122,195,118"/>
<Label Content="getGreet" HorizontalAlignment="Left" Margin="187,90,0,0" VerticalAlignment="Top"/>
<Button Content="Finish" Command="{Binding Refresh}" HorizontalAlignment="Left" Margin="112,163,0,0" VerticalAlignment="Top" Width="75"/>
</Grid>
</Window>
MainView.xaml.cs
//using MVVM.Models;
using MVVM.ViewModels;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
namespace MVVM.Views
{
/// <summary>
/// Interaction logic for UI.xaml
/// </summary>
public partial class MainView : Window
{
public MainView()
{
InitializeComponent();
this.DataContext = new MainViewModel();
}
}
}
And Main Files...
App.xaml
<Application x:Class="MVVM.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Startup="OnStartup">
<Application.Resources>
</Application.Resources>
</Application>
App.xaml.cs
using MVVM.ViewModels;
using MVVM.Views;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Windows;
namespace MVVM
{
/// <summary>
/// Interaction logic for App.xaml
/// </summary>
public partial class App : Application
{
public void OnStartup(object sender, StartupEventArgs e)
{
// Create the ViewModel and expose it using the View's DataContext
MainView view = new MainView();
view.DataContext = new MainViewModel();
view.Show();
}
}
}
Please help.

Answer 1

You are binding to the Name property of your MainViewModel not the Name property of your Model. Even thought this is essentially a passthrough to the Model.Name property, the binding is attaching to the PropertyChanged event of the MainViewModel which doesn't get raised in your setter.
Add an OnPropertyChanged call in the setter of your MainViewModel.Name property and it should work.
public string Name
{
get { return _name; }
set
{
_name = value;
FModel.Name = value;
OnPropertyChanged("Name");
}
}