WPF ComboBox binding automatically

Question

I'm making chatting program and I have an API for connect to chat server.

in API here is main class.

public partial class PengChat3ClientSock : IDisposable

well, I overrided ToString method too.

public override string ToString()
    {
        string s;

        if (ConnectedIP != null && ConnectedPort != null)
            s = ConnectedIP + ':' + ConnectedPort.Value.ToString();
        else
            return "";

        if (string.IsNullOrEmpty(Nickname))
            return s;
        else
            return s + " \"" + Nickname + "\"";
    }

Well, in client program,

this is a list of sockets

private List<PengChat3ClientSock> socketList = new List<PengChat3ClientSock>();

And i have combobox which is to showing connection list

<ComboBox Grid.Row="0" Grid.ColumnSpan="2" Height="20">                   
</ComboBox>

Now, i want to bind ComboBox ItemsSource with variable socketList

I want to add/remove socket list when client create a new socket, and push back to the socketList or remove from the socketList.

It is possible?

Thanks.

Answer 1

Use an ObservableCollection<PengChang3ClientSock> instead of a plain list. The ObservableCollection will raise and CollectionChangedEvent when items are added or removed from the collection to notify bound controls.

Set the ObservableCollection as ItemsSource of the ComboBox like

<ComboBox Grid.Row="0" Grid.ColumnSpan="2" Height="20" ItemsSource="{Binding Sockets}">                   
</ComboBox>

This setup requires that the DataContext (ViewModel) of the ComboBox has a property Sockets encapsulating your ObservableCollection.

public ObservableCollection Sockets{
  get{
    return socketList;
  }
}

Answer 2

You should use ObservableCollection.

private ObservableCollection<PengChat3ClientSock> socketList = new ObservableCollection<PengChat3ClientSock>();

Then name combobox in XAML

<ComboBox Name="SocketListComboBox" Grid.Row="0" Grid.ColumnSpan="2" Height="20">                   
</ComboBox>

And in code (xaml.cs), in constructor just after InitializeComponents(); do

SocketListComboBox.ItemsSource = socketList;

Other way is to bind it in XAML;

<ComboBox Name="SocketListComboBox" Grid.Row="0" Grid.ColumnSpan="2" Height="20" ItemsSource = "{Binding socketList}">                   
</ComboBox>

In constructor set ComboBox DataContext to owner of socketList; And socketList must be a property with public get.

public ObservableCollection<PengChat3ClientSock> socketList {get; protected set; }

Answer 3

Yes you can. You should hold the list of sockets in an ObservableCollection

private ObservableCollection]<PengChat3ClientSock> socketList = new List<PengChat3ClientSock>();

Then add a binding to the combobox like this:

ComboBox Grid.Row="0" Grid.ColumnSpan="2" Height="20" ItemSource="{Binding socketList}>                   

The last thing you need to do is to set the DataContext of the Window with the ComboBox to the class which has the list.

DataContext = new ClassWithSocketList();

From now on every action you'll make on the list would have binding to the list.