How to properly use datacontext multiple ways - windows-phone-7

Question

OK, so I wanted to use a color picker and found Alex Yakhnin's blog...
http://blogs.msdn.com/b/priozersk/archive/2010/09/17/customizing-picker-box-dialog.aspx
after implementing this code from the blog:
DialogViewModel viewModel;
PickerBoxDialog customDialog;
ColorItem currentColorItem;
private void InitCustomPickerDialog()
{
// Initialize viewmodel
this.viewModel = new DialogViewModel();
this.currentColorItem = viewModel.Items[0];
// Assing it to the page's DataContext
this.DataContext = currentColorItem;
this.customDialog = new PickerBoxDialog();
this.customDialog.Title = "ACCENTS";
// Assign our style to the dialog
this.customDialog.Style = this.Resources["Custom"] as Style;
this.customDialog.ItemSource = viewModel.Items;
this.customDialog.Closed += new EventHandler(customDialog_Closed);
}
void customDialog_Closed(object sender, EventArgs e)
{
this.currentColorItem = (ColorItem)this.customDialog.SelectedItem;
this.DataContext = currentColorItem;
}
private void buttonColor_Click(object sender, RoutedEventArgs e)
{
this.customDialog.Show();
}
I realized that the page's datacontext is being used to set the colors for the picker. I am using a listbox on this same page which also sets the datacontext of the page to display a list of fish.
public FishsPage()
{
InitializeComponent();
DataContext = App.vmFish;
InitCustomPickerDialog();
}
Therefore, I need the page's datacontext for 2 different things now. Is there a way to use the color picker control and the fish list simultaneously?
Erno's suggestion?:
public class FishViewModelComplete : INotifyPropertyChanged
{
private readonly ReefServiceClient wcfProxy;
public FishViewModelComplete()
{
vmFish = new FishViewModel();
vmDialog = new DialogViewModel();
}
private FishViewModel _vmFish;
public FishViewModel vmFish
{
get
{
return _vmFish;
}
set
{
_vmFish = value;
}
}
private DialogViewModel _vmDialog;
public DialogViewModel vmDialog
{
get
{
return _vmDialog;
}
set
{
_vmDialog = value;
}
}
}

Answer 1

Create a third ViewModel that exposes the two ViewModels through properties and bind the appropriate controls to these.