How to Update Model from the View - wpf

Question

I have Model Class Employee:
public class Employee
{
public string Id { get; set; }
public string Name { get; set; }
public string LastName { get; set; }
}
and View Model class EmployeeViewModel which contains an Employee Object
public class EmployeeViewModel : INotifyPropertyChanged
{
public EmployeeViewModel()
{
}
private Employee currentEmployee;
public Employee CurrentEmployee
{
get { return this.currentEmployee; }
set
{
this.currentEmployee = value;
this.NotifyPropertyChanged("CurrentEmployee");
}
}
//Some code .....
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(string propertyName)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
#endregion
}
Now the View (WPF) will use Employee object in the View Model as ItemSource to display Employee data
Now the question is: I have Update button on the view and when I change the Employee properties in the view (via text boxes) I want to update the model (so afterward i can update the database), how to update this model from the view.

Answer 1

As I checked there something weird with your Model Class. It is the one that should implement INotifyPropertyChanged then create backing fields for each property something like this.
Model Class
public class Employee:INotifyPropertyChanged
{
private string _name;
public string Name
{
get
{
return _name;
}
set
{
_name= value;
OnPropertyChanged("Name");
}
}
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
#endregion
}
**ViewModel Class**
class EmployeeViewModel
{
private IList<Employee> _employees;
public EmployeeViewModel()
{
_employees= new List<Employee>
{
new Employee{ID=1, Name ="Emp1"},
new Employee{ID=2, Name="Emp2"}
};
}
public IList<Employee> Employees
{
get
{
return _employees;
}
set
{
_employees= value;
}
}
private ICommand mUpdater;
public ICommand UpdateCommand
{
get
{
if (mUpdater == null)
mUpdater = new Updater();
return mUpdater;
}
set
{
mUpdater = value;
}
}
private class Updater : ICommand
{
#region ICommand Members
public bool CanExecute(object parameter)
{
return true;
}
public event EventHandler CanExecuteChanged;
public void Execute(object parameter)
{
}
#endregion
}
}
You may put your logic inside OnPropertyChanged event. This method is always called whenever you made changes on the UI

Answer 2

If you are using ObservableCollection modify your List by searching the item based on ID then if found do the modification of values. Whatever changes you have made will automatically affect the UI items if they are bound to your ObservableCollection then use the modified collection to update your DB records