ComboBox Column and ItemsSourceBinding, changes not commited

[Alex]

I'm trying to use ItemsSourceBinding. The list is displayed but the selected item is not commited to binded property (see attached picture).
XAML:

<telerik:RadGridView Name="playersGrid"
                             ItemsSource="{Binding Players}"
                             AutoGenerateColumns="False">

            <telerik:RadGridView.Columns>
                <telerik:GridViewDataColumn DataMemberBinding="{Binding Name}"/>
                <telerik:GridViewDataColumn DataMemberBinding="{Binding Number}"/>
                <telerik:GridViewDataColumn DataMemberBinding="{Binding Position}"/>
                <telerik:GridViewDataColumn DataMemberBinding="{Binding Country}" IsReadOnlyBinding="{Binding IsReadOnlyProperty}"/>

                <telerik:GridViewComboBoxColumn DataMemberBinding="{Binding ClubID}"
                                                SelectedValueMemberPath="ID"
                                                ItemsSourceBinding="{Binding AvailableClubs}"
                                                DisplayMemberPath="Name" />
            </telerik:RadGridView.Columns>
        </telerik:RadGridView>

ViewModel:

/// <summary>
/// A football player.
/// </summary>
public class Player : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    private string name;
    private int number;
    private Position position;
    private string country;


    private bool isReadOnlyProperty;
    public bool IsReadOnlyProperty
    {
        get { return this.isReadOnlyProperty; }
        set
        {
            if (value != this.isReadOnlyProperty)
            {
                this.isReadOnlyProperty = value;
                this.OnPropertyChanged("IsReadOnlyProperty");
            }
        }
    }
    private int clubID;
    public int ClubID
    {
        get { return this.clubID; }
        set
        {
            if (value != this.clubID)
            {
                this.clubID = value;
                this.UpdateIsReadOnlyProperty(this.clubID);
                this.OnPropertyChanged("ClubID");

            }
        }
    }


    public string Name
    {
        get { return this.name; }
        set
        {
            if (value != this.name)
            {
                this.name = value;
                this.OnPropertyChanged("Name");
            }
        }
    }

    public int Number
    {
        get { return this.number; }
        set
        {
            if (value != this.number)
            {
                this.number = value;
                this.OnPropertyChanged("Number");
            }
        }
    }

    public Position Position
    {
        get { return this.position; }
        set
        {
            if (value != this.position)
            {
                this.position = value;
                this.OnPropertyChanged("Position");
            }
        }
    }

    public string Country
    {
        get { return this.country; }
        set
        {
            if (value != this.country)
            {
                this.country = value;
                this.OnPropertyChanged("Country");
            }
        }
    }

    public IEnumerable<Club> AvailableClubs
    {
        get
        {
            return from c in Club.GetClubs()
                   where c.ID == this.ClubID
                   select c;
        }
    }

    public Player()
    {

    }

    public Player(string name, int number, Position position, string country, int clubID, bool isReadOnlyProperty)
    {
        this.name = name;
        this.number = number;
        this.position = position;
        this.country = country;
        this.clubID = clubID;
        this.isReadOnlyProperty = isReadOnlyProperty;
    }

    protected virtual void OnPropertyChanged(PropertyChangedEventArgs args)
    {
        PropertyChangedEventHandler handler = this.PropertyChanged;
        if (handler != null)
        {
            handler(this, args);
        }
    }

    private void OnPropertyChanged(string propertyName)
    {
        this.OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
    }

    public override string ToString()
    {
        return this.Name;
    }

    public static ObservableCollection<Player> GetPlayers()
    {
        return new ObservableCollection<Player>(Club.GetClubs().SelectMany(c => c.Players));
    }

    private void UpdateIsReadOnlyProperty(int clubID)
    {
        if (clubID == 2 || clubID == 3)
        {
            this.IsReadOnlyProperty = true;
        }
        else
        {
            this.IsReadOnlyProperty = false;
        }
    }
}

This sample is based on SL sample attached by Maya here: http://www.telerik.com/community/forums/silverlight/gridview/binding-from-radgridview-to-radcombobox.aspx 

[Nick]

Hello Alex,

Have you tried setting the SelectedValueMemberPath to "ClubID"?

Greetings,
Nik
the Telerik team

[Alex]

I can not understand how this will help. Look, AvailableClubs binded to combobox column ItemsSourceBinding is list of Club instances. In class club there is no "ClubID" property. Its identifier is ID property. So SelectedValueMemberPath set to "ID". ClubID is property of Player class, which is used as grid row context. So we bind column DataMemberBinding to this property.
But nevertheless I checked your advice, he predictably does not help.
I can not attach here but I can send you ready project so you can easily reproduce this problem.

[Nick]

Hello Alex,

I am sorry for misdirecting you. It would be great if you could provide the sample project you are using via support ticket. 

Looking forward to hearing from you! 

Regards,
Nik
the Telerik team

[Alex]

Support ticket: http://www.telerik.com/account/support-tickets/view-ticket.aspx?threadid=609761 

[Nick]

Hi Alex,

I have looked into your project and I believe I have found the problem. The itemssourse you give to the combo box column consists only of clubs that have the same id as the one of the player in the current row. Therefore, the lookup value in the combo box and the bound one are the same - therefore there isn't a change fired when you change the club. 
Now, you can see that if you modify the Clubs collection to contain other clubs as well, everything works as expected. 

return  (from c in Club.GetClubs()
        //where c.ID == this.ClubID
        select c).ToList();

Copy Code

Hope this makes sense! 


Regards,
Nik
the Telerik team

[Ravindra]

Hi Alex,

In this example, for the combo box item selection , property changed event is not triggered until we press enter or loose the focus.
How the property value will be changed for the selected item directly after selecting it from the combobox without loosing the focus or pressing enter key.

[Dinko | Tech Support Engineer]

Hello Ravindra,

What I can suggest you is to add a handler for the SelectionChanged event of RadComboBox (which is the editing element of GridViewComboBoxColumn). In the event handler, you can commit the selected object using the CommitEdit() method of the RadGridView.

public MainWindow()
{
    InitializeComponent();
    this.AddHandler(RadComboBox.SelectionChangedEvent, new SelectionChangedEventHandler(OnSelectionChanged));
}

private void OnSelectionChanged(object sender, SelectionChangedEventArgs e)
{
    if (e.RemovedItems.Count > 0)
    {
        this.myGrid.CommitEdit();
    }
}

Regards,
Dinko
Progress Telerik