How to bind a CommandParameter in a ContentView to an element in the parent ContentPage in Xamarin Forms

Question

I have a parent ContentPage with several ContentViews in separate files. I am trying to pass as reference an element in the parent ContentView to a CommandParameter in one

Answer 1

You could check the following code

in AddressChipView.xaml

Since you had used Custom ContentView , you need use bindable property to binding value between the elements in ContentView and Parent ContentPage

<?xml version="1.0" encoding="UTF-8" ?>
<ContentView
x:Class="Acies.NitroT.Views.Home.AddressChipView"
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:behaviors="clr-namespace:Acies.NitroT.Behaviors"
xmlns:buttons="clr-namespace:Syncfusion.XForms.Buttons;assembly=Syncfusion.Buttons.XForms"
xmlns:d="http://xamarin.com/schemas/2014/forms/design"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:controls="clr-namespace:Acies.NitroT.Controls;assembly=Acies.NitroT.Mobile.Shared"
mc:Ignorable="d"

x:Name="ChipView" // set the name of AddressChipView

>

<buttons:SfChipGroup
                ChipPadding="2,0,0,0"
                Command="{Binding Source={x:Reference ChipView}, Path=SelectedAddressCommand}"
                //...
                SelectedItem="{Binding Source={x:Reference ChipView}, Path=SelectedAddress}"
                ShowIcon="True"
                Type="Choice">
                <buttons:SfChipGroup.Behaviors>
                    <behaviors:EventToCommandBehavior
                        Command="{Binding Source={x:Reference ChipView}, Path=AddressSelectionChangedCommand}"
                        CommandParameter="{Binding Source={x:Reference ChipView}, Path=CurrentMapView}"
                        EventName="SelectionChanged" />
                </buttons:SfChipGroup.Behaviors>
            </buttons:SfChipGroup>

in AddressChipView.xaml.cs

public static readonly BindableProperty AddressSelectionChangedCommandProperty =
            BindableProperty.Create(nameof(AddressSelectionChangedCommand), typeof(ICommand), typeof(AddressChipView));

        public ICommand AddressSelectionChangedCommand
        {
            get => (ICommand)GetValue(AddressSelectionChangedCommandProperty );
            set => SetValue(AddressSelectionChangedCommandProperty , value);
        }

        public static BindableProperty CurrentMapViewProperty =
            BindableProperty.Create(nameof(CurrentMapView), typeof(object), typeof(AddressChipView));

        public object CurrentMapView
        {
            get => (object)GetValue(CurrentMapViewProperty );
            set => SetValue(CurrentMapViewProperty , value);
        }

        //... other bindable property  
       

Now you can binding it in ContentPage

<homeViews:AddressChipView Grid.Row="1"  AddressSelectionChangedCommand={Binding xxxCommand}  CurrentMapView = {Binding Source={x:Reference Map}, Path=.} />