WPF how to fill combobox in data grid

Question

public class DA_ActivityType { public int Id { get; set; } public string Name { get; set; } }

public static List<DA_ActivityType> GetActivitytypes()
{
    DataContext dbo = new DataContext();
    IEnumerable<DA_ActivityType> activityTypes =
                     from actType in dbo.ActivityTypes
                     select new DA_ActivityType
                     {
                         Id = actType.TypeId,
                         Name = actType.Name

                     };

    return activityTypes.ToList();
}

//XAML Code

<Grid>
    <Grid.Resources>
        <ObjectDataProvider x:Key="ActivityTypes" ObjectType="{x:Type  c:ActivityType}" MethodName="GetActivitytypes" />
    </Grid.Resources>
    <DataGrid AllowDrop="False" AutoGenerateColumns="False" HorizontalAlignment="Stretch" HorizontalContentAlignment="Left" Margin="1,2,-1,-2" Name="DefineManulaColumns" SelectionMode="Single" VerticalAlignment="Stretch">
        <DataGrid.Columns>
            <DataGridTextColumn Binding="{Binding ActivityName}" Header="Activity" />
            <DataGridTextColumn Binding="{Binding Path=CreatedTime, StringFormat=\{0:D\}}" Header="Created" ClipboardContentBinding="{Binding}" />
            <DataGridTextColumn Binding="{Binding Path=StartTime, StringFormat=\{0:f\}}" Header="Start" />
            <DataGridTextColumn Binding="{Binding EndTime}" Header="End" />
            <DataGridCheckBoxColumn Binding="{Binding Path=Archived}" Header="Archived"/>
            <DataGridTemplateColumn Header="Type">
                <DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding ActivityName}" />
                    </DataTemplate>
                </DataGridTemplateColumn.CellTemplate>
                <DataGridTemplateColumn.CellEditingTemplate>
                    <DataTemplate>
                        <ComboBox SelectedItem="{Binding ActivityName}" DisplayMemberPath="{Binding Name}"  ItemsSource="{Binding Source={StaticResource ActivityTypes}}" />
                    </DataTemplate>
                </DataGridTemplateColumn.CellEditingTemplate>
            </DataGridTemplateColumn>
        </DataGrid.Columns>
        <DataGrid.AlternatingRowBackground>
            <LinearGradientBrush EndPoint="1,0.5" StartPoint="0,0.5">
                <GradientStop Color="#FFC4DCFF" Offset="0" />
                <GradientStop Color="#FFEFF4F8" Offset="1" />
                <GradientStop Color="#FF79B7F8" Offset="0.558" />
            </LinearGradientBrush>
        </DataGrid.AlternatingRowBackground>
    </DataGrid>
</Grid>

Answer 1

Either:

<ComboBox x:Name="myCombo" />
myCombo.ItemsSource = GetMyCollection();

or :

<ComboBox ItemsSource="{Binding}" />
and one of the parent elements must have the DataContext = GetMyCollection();