Question

I have a datagrid, bound to a List:

<DataGrid HorizontalAlignment="Left" SelectedItem="{Binding CurrentPlayer}" Height="374" Margin="121,22,0,0" RowHeaderWidth="0" VerticalAlignment="Top" Width="836" ItemsSource="{Binding Players}" AutoGenerateColumns="false" IsReadOnly="True" SelectionMode="Single" >

As you can see, when an item is selected, it’s stored in the CurrentPlayer property. The properties of that object are bound to textboxes where the user can edit the values.

The problem I have is: due to the binding, when the user edits the information (edits player name, address,..), the changes are immediatly shown in the datagrid, even when the user didn’t press the Save-button yet.

I don’t want that obviously as there’s also a cancel option and validation. I know you can bind one time or one way, but when the user DOES press the save button, the changes SHOULD show.

Is there any way to do this?

Answer 1

One possible solution:

have a baseclass for the viewmodel:

class BaseClassViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected void NotifyPropertyChanged(String info)
    {
        if (PropertyChanged != null)
        {
            Debug.Print(info);
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }
}

Make each property for each field for the selected object a get set property in this form:

    public string FieldInObject
    {
        get
        {
            return _FieldInObject;
        }
        set
        {
            if (value != _FieldInObject)
            {
                _FieldInObject = value;
                //do not add this code here
                //NotifyPropertyChanged("CurrentPlayer");
            }
        }
    }

When the user presses the save button then use

NotifyPropertyChanged("CurrentPlayer");
NotifyPropertyChanged("<Property 1 in currentPlayer>"); 
 .....
NotifyPropertyChanged("<Property n in currentPlayer");

It should notify the WPF to update the CurrentPlayer.

I hope this is somewhat understandable. Just use NotifyPropertyChanged to signal the WPF to update that field that is binded to that property.