Access a Label placed inside a ContentView inside a ResourceDictionary - xaml

Question

I have below XAML which contains ContentView inside my main XAML.
I want to know how can I access the LabelPushNotificationPrice to change the Text?
<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:SyncfusionBusyIndicator="clr-namespace:Syncfusion.SfBusyIndicator.XForms;assembly=Syncfusion.SfBusyIndicator.XForms"
x:Class="ZayedAlKhair.InitiativeDetails"
xmlns:SyncfusionPopup="clr-namespace:Syncfusion.XForms.PopupLayout;assembly=Syncfusion.SfPopupLayout.XForms"
Title="زايد الخير">
<ContentPage.Resources>
<ResourceDictionary>
<DataTemplate x:Key="PushNotificationsViewTemplate">
<ContentView BackgroundColor="White" x:Name="PushNotificationsContentView">
<StackLayout Padding="15">
<Label HorizontalTextAlignment="End" Text="هذه الخدمة تمكنكم من إرسال تنبيهات الهواتف الذكية لجميع مشتركي تطبيق زايد الخير وهي أفضل خدمة لتصل مبادرتكم لآلاف المشتركين" HeightRequest="90" WidthRequest="100" />
<Label x:Name="**LabelPushNotificationPrice**" HorizontalTextAlignment="End" Text="سعر الخدمة : 499 دولار" HeightRequest="30" WidthRequest="100" />
<Label HorizontalTextAlignment="End" Text="مدة الترويج : مرة واحدة لكل مبادرة" HeightRequest="30" WidthRequest="100" />
</StackLayout>
</ContentView>
</DataTemplate>
<DataTemplate x:Key="PromoteViewTemplate">
<ContentView BackgroundColor="White" x:Name="PromoteContentView">
<StackLayout Padding="15">
<Label HorizontalTextAlignment="End" Text="هذه الخدمة ستجعل مبادرتكم مميزة باللون الأحمر ودائما في أعلى القائمة ليتمكن كل مستخدمي التطبيق من التعرف عليها والتفاعل معها" HeightRequest="90" WidthRequest="100" />
<Label HorizontalTextAlignment="End" Text="سعر الخدمة : 99 دولار" HeightRequest="30" WidthRequest="100" />
<Label HorizontalTextAlignment="End" Text="مدة التمييز : 30 يوما" HeightRequest="30" WidthRequest="100" />
</StackLayout>
</ContentView>
</DataTemplate>
</ResourceDictionary>
</ContentPage.Resources>
<ContentPage.Content>
<Grid Padding="10" x:Name="GridInitiativeDetails">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>

Answer 1

The preferred way is to use DataBindings, example:
<Label HorizontalTextAlignment="End" Text="{Binding LabelPushNotificationPrice}" />
This way you can seamlessly update the value of the Label bound to your ViewModel. The point is to separate UI layer from your BL layer and usually we use MVVM rather than MVC in Xamarin.Forms. The official documentation is nicely covering this topic and there are free e-books like Enterprise Application Patterns using Xamarin.Forms that I recommend to read additionally.
P.S.: Please note that setting a fixed Height & Width on UI controls may break your UX experience on screens with different sizes.