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I have a ContentView with a Bindable property. This property is set from the main page and it is setting correctly as I am seeing it in PropertyChanged function. Now I want to bind this value to the property of ViewModel of ContentView.

I can see debug point coming on OnChange in View's DP when set from MainPage, but it is not setting ViewModel property.

Appreciate your help!

What I have tried:

MainView.xaml.cs

public static readonly BindableProperty ContentViewDependencyProperty = BindableProperty.Create(
			"ContentViewDp",
			typeof(string),
			typeof(MainView),
			null, propertyChanged:OnChange);

		public string ContentViewDp
		{
			get { return (string)GetValue(ContentViewDependencyProperty ); }
			set { SetValue(ContentViewDependencyProperty , value); }
		}
private static void OnChange(BindableObject bindable, object oldValue, object newValue)
		{

		}


MainView.xaml

<ContentView xmlns="http://xamarin.com/schemas/2014/forms" 
			 xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
			 x:Class="MyProject.MainView"
			 BackgroundColor="White"
			 xmlns:local="clr-namespace:MyProject.Views;assembly=MyProject.Mobile"
			 xmlns:vm="clr-namespace:MyProject.ViewModels;assembly=MyProject.Mobile"
			 NavigationPage.HasNavigationBar="False">
    <ContentView.BindingContext>
		<vm:MainViewModel/>
	</ContentView.BindingContext>
	<ContentView.Resources>
		<Style TargetType="local:MainView">
			<Setter Property="ContentViewDp" Value="{Binding ViewModelProperty, Mode=TwoWay}"/>
		</Style>
	</ContentView.Resources>
</ContentView>


ViewModel.cs:

private string _viewModelProperty;
		public string ViewModelProperty
		{
			get { return _viewModelProperty; }
			set { SetProperty(ref _viewModelProperty, value, nameof(ViewModelProperty)); }
		}
Posted
Updated 21-Sep-22 23:50pm

1 solution

you set the binding to:
XML
<vm:MainViewModel/>

But above you state the class/file name is ViewModel.cs
In the ContentView.xaml, use:
XML
<ContentView xmlns="http://xamarin.com/schemas/2014/forms" 
			 xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
			 x:Class="MyProject.MainView"
			 BackgroundColor="White"
			 xmlns:local="clr-namespace:MyProject.Views;assembly=MyProject.Mobile"
			 xmlns:vm="clr-namespace:MyProject.ViewModels;assembly=MyProject.Mobile"
			 NavigationPage.HasNavigationBar="False"

             x:DataType="vm:MainViewModel">

Also set XmlCompilationOptions.Compile in Assembly.cs.

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