CODEWITHSUNDEEP
xamarinxamarin.forms
user875234
user875234

Reputation: 2517

How do you set a binding context in a ListView with respect to the outer binding context?

The code below should give you a pretty good idea of what I'm working with. Each Widget gets displayed in the ListView. But some of the widgets are "On Fire" and I would like to display their StreetName in red. The problem is the record of which widgets are on fire is kept in the WidgetsViewModel.

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage 
                xmlns="http://xamarin.com/schemas/2014/forms"
                xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                x:Class="SickProgram.Views.Pages.WidgetsPage"
                xmlns:ViewModels="clr-namespace:SickProgram.ViewModels">

    <ContentPage.BindingContext>
        <ViewModels:WidgetsViewModel />
    </ContentPage.BindingContext>

    <StackLayout>
        <ListView ItemsSource="{Binding Widgets}">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <ViewCell>
                        <StackLayout>
                            <Label Text="{Binding StreetName}"/>
                        </StackLayout>
                    </ViewCell>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>
    </StackLayout>

</ContentPage>

In a perfect world it would look something like:

<!- OnFire is a method in the WidgetsViewModel that takes in a widget Id and returns a color. ->
<Label Text="{Binding StreetName}" Color={Binding BindingContext.Parent.OnFire(BindingContext.Id)}/>

Also, I don't think using the selected item will get the job done. The display of on fire widgets should be independent from the display of the selected item.

Upvotes: 1

Views: 706

Answers (1)

Neil
Neil

Reputation: 637

we can tackle the problem about OnFire widgets having a separate color later.

You could define datatemplates and use a data template selector. Please see https://learn.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/templates/data-templates/selector

Each item that the list view is going to display will invoke the selector. if you can determine whether a widget is onFire by looking at some properties in the object. this method would work. if not let me know there are some other thoughts.

sorry I tried to format the output of this post.

Upvotes: 1

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