How to call command inside listbox in silverlight4 - xaml

Question

I am using Listbox and it contains button ,and i want to handle button click event using command.but my command never calls.
is this Correct way??
<pmControls:pmListBox Grid.Row="1" Margin="3" ItemsSource="{Binding Countries}" SelectedItem="{Binding SelectedCountry}" >
<pmControls:pmListBox.ItemTemplate >
<DataTemplate >
<Button Command="{Binding GetAllStatesCommand}" CommandParameter="{Binding}" Margin="3" Width="100" Height="50" Content="{Binding Title}">
</Button>
</DataTemplate>
</pmControls:pmListBox.ItemTemplate>
</pmControls:pmListBox>

Answer 1

The DataContext of one list item is different from the DataContextof the surrounding control. To bind that command to the DataContext of that control you have two options:
Either you provide the control with a name and reference to that:
<pmControls:pmListBox x:Name="myCoolListBox" [...]>
<pmControls:pmListBox.ItemTemplate>
<DataTemplate>
<Button Command="{Binding DataContext.GetAllStatesCommand, ElementName=myCoolListBox}" CommandParameter="{Binding}" [...] />
</DataTemplate>
</pmControls:pmListBox.ItemTemplate>
</pmControls:pmListBox>
Or you create class holding your DataContext...
public class DataContextBinder : DependencyObject
{
public static readonly DependencyProperty ContextProperty = DependencyProperty.Register("Context", typeof(object), typeof(DataContextBinder), new PropertyMetadata(null));
public object Context
{
get { return GetValue(ContextProperty); }
set { SetValue(ContextProperty, value); }
}
}
...and create an instance of that in the resources section of your ListBox:
<pmControls:pmListBox x:Name="myCoolListBox" [...]>
<pmControls:pmListBox.Resources>
<local:DataContextBinder x:Key="dataContextBinder" Context="{Binding}" />
</pmControls:pmListBox.Resources>
<pmControls:pmListBox.ItemTemplate>
<DataTemplate>
<Button Command="{Binding Context.GetAllStatesCommand, Source={StaticResource dataContextBinder}" CommandParameter="{Binding}" [...] />
</DataTemplate>
</pmControls:pmListBox.ItemTemplate>
</pmControls:pmListBox>