Xamarin forms Switch Toggled event fires automatically whenever navigate to that page

Question

I am using Xamarin forms switch inside collection view like the below.

  <CollectionView ItemsSource="{Binding SwitchStatus}">
                <CollectionView.ItemTemplate>
                    <DataTemplate>
                        <StackLayout>
                            <StackLayout HeightRequest="100" Orientation="Horizontal" HorizontalOptions="CenterAndExpand" Spacing="30">
                                <Switch x:Name="mySwitch" IsToggled="{Binding State}"> 
                                    <Switch.Behaviors>
                                        <prism:EventToCommandBehavior EventName="Toggled" CommandParameter="{Binding .}" Command="{Binding BindingContext.UpdateCommand,Source={x:Reference myPage}}"/>
                                    </Switch.Behaviors>
                                </Switch>
                            </StackLayout>
                        </StackLayout>
                    </DataTemplate>
                </CollectionView.ItemTemplate>

            </CollectionView>

Toggled event of the Switch getting fired automatically whenever I navigate to that page because of IsToggled Binding property set. Is there any way to restrict Switch Toggled event when the user not manually triggered?

To be more clear, I have attached my sample here.

Followed prism MVVM, EventToCommandBehavior I should follow all these.

Help me with the sample code would be greatful.

score 1 · Answer 1 · answered Apr 17 '21 at 06:20

. Is there any way to restrict Switch Toggled event when the user not manually triggered?

I'm afraid there is no method to achieve it .

First , Check the source code of Switch .

public static readonly BindableProperty IsToggledProperty = BindableProperty.Create(nameof(IsToggled), typeof(bool), typeof(Switch), false, propertyChanged: (bindable, oldValue, newValue) =>
        {
            ((Switch)bindable).Toggled?.Invoke(bindable, new ToggledEventArgs((bool)newValue));
            ((Switch)bindable).ChangeVisualState();
        }, defaultBindingMode: BindingMode.TwoWay);

It is clear that Toggled event would trigger if the IsToggled property changes .

In other word ,no matter we toggle the switch manually or changes IsToggled programmatically , Toggled will be triggerd , and then EventToCommandBehavior will works after that .

I agree with your point but that doesn't answer my question. I achieved it with my own logic. Thanks. — Jay, Apr 26 '21 at 20:22
Hi there, would you mind sharing how you fixed? I have the same issue. — ledragon, Aug 20 '21 at 14:58

Xamarin forms Switch Toggled event fires automatically whenever navigate to that page

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