code1(it dosen't work):
<DataGrid x:Name="TcDataGrid" CurrentCell="{Binding CurrentCell}">
<DataGrid.ContextMenu>
<ContextMenu x:Name="Menu" StaysOpen="False" DataContext="{Binding Data,Source={StaticResource BindingProxy}}" >
<ContextMenu.ItemsSource>
<MultiBinding Converter="{StaticResource ResourceKey= GridCellMenuConverter}" >
<Binding Path="Data.ItemsSource" Source="{StaticResource BindingProxy}"/>
<Binding Path="Data.CurrentCell" Source="{StaticResource BindingProxy}"/>
</MultiBinding>
</ContextMenu.ItemsSource>
</ContextMenu>
</DataGrid.ContextMenu>
</DataGrid>
code 2(it works):
<ContextMenu.ItemsSource>
<Binding Path="ItemsSource"></Binding>
</ContextMenu.ItemsSource>