Changing ItemTemplate of ItemControl placed inside DataTemplate of pivot control in windows phone 8

Question

I am new to windows phone 8 development. I am trying to create a calendar like layout in my application. For that I used Pivot control as in the xaml below

<phone:Pivot x:Name="Piv" ItemsSource="{Binding Months}" Grid.Row="1" Margin="0,-10,0,0">
    <phone:Pivot.HeaderTemplate>
        <DataTemplate>
            <TextBlock Margin="0,0,0,0" Text="{Binding Name}" Height="70" FontSize="50"/>
        </DataTemplate>
    </phone:Pivot.HeaderTemplate>
    <phone:Pivot.ItemTemplate>
        <DataTemplate>
            <StackPanel Margin="0,-20,0,0">
                <Grid Margin="0,0,0,0" >        
                    <!-- Header items goes here -->
                </Grid>
                <ItemsControl x:Name="CalendarControl"  ItemsSource="{Binding Days}" ItemTemplate="{StaticResource HorizontalPivotTemplate}" >
                    <ItemsControl.ItemsPanel>
                        <ItemsPanelTemplate>
                            <Grid x:Name="CalGrid">
                                <!--Colums and rows for layout goes here-->
                            </Grid>
                        </ItemsPanelTemplate>
                    </ItemsControl.ItemsPanel>
                </ItemsControl>
            </StackPanel>
        </DataTemplate>
    </phone:Pivot.ItemTemplate>
</phone:Pivot>

For Itemcontrol, I have two DataTemplates defined as page resource as given below.

<phone:PhoneApplicationPage.Resources>
        <DataTemplate x:Key="VerticalPivotTemplate">
            <Grid  MinWidth="65" local:ItemsGridLayout.GridRow="{Binding Week}" 
                                        local:ItemsGridLayout.GridColumn="{Binding WeekDay}">
                <Border BorderThickness="1" BorderBrush="White" >
                    <Grid Height="76">
                        <TextBlock VerticalAlignment="Top" HorizontalAlignment="Left" Text="{Binding Day}"  Style="{StaticResource PhoneTextLargeStyle}"/>
                        <TextBlock VerticalAlignment="Bottom" HorizontalAlignment="Right" Text="{Binding DayMalayalam}"  FontSize="16"/>
                    </Grid>
                </Border>
            </Grid>
        </DataTemplate>
        <DataTemplate x:Key="HorizontalPivotTemplate">
            <Grid  MinWidth="65" local:ItemsGridLayout.GridRow="{Binding Week}" 
                                        local:ItemsGridLayout.GridColumn="{Binding WeekDay}">
                <Border BorderThickness="1" BorderBrush="White" >
                    <Grid Height="56">
                        <TextBlock VerticalAlignment="Top" HorizontalAlignment="Left" Text="{Binding Day}"  Style="{StaticResource PhoneTextLargeStyle}"/>
                        <TextBlock VerticalAlignment="Bottom" HorizontalAlignment="Right" Text="{Binding DayMalayalam}"  FontSize="16"/>
                    </Grid>
                </Border>
            </Grid>
        </DataTemplate>
    </phone:PhoneApplicationPage.Resources>

Now, my requirement is to choose between these templates and assign it to ItemControl's ItemTemplate when phone's orientation changes. For that I used OrientationChanged event of phone application page.

private void PhoneApplicationPage_OrientationChanged_1(object sender, OrientationChangedEventArgs e)
        {
            if (e.Orientation == PageOrientation.PortraitDown || e.Orientation == PageOrientation.PortraitUp)
            {
                //Assign VerticalPivotTemplate as CalendarControl's ItemTemplate
            }
            else
            {
               //Assign HorizontalPivotTemplate as CalendarControl's ItemTemplate
            }
        }

I don't know what to write in the event to achieve my requirement. I am unable to access CalendarControl ItemControl here. Please someone help me

Answer 1

I can't help noticing that you are just changing your grids width in DataTemplate, why dont you just use triggers to do that instead of changing the whole template..

        <Grid.Style>
            <Style TargetType="Grid">
                <Setter Property="Width" Value="56"/>
                <Style.Triggers>
                    <DataTrigger Binding="{Binding Orientation, RelativeSource={RelativeSource AncestorType={x:Type phone:PhoneApplicationPage}}}" Value="PortraitDown">
                        <Setter Property="Width" Value="76"/>
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </Grid.Style>