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frostydog47
frostydog47

Reputation: 157

Why is my MenuFlyoutItem text binding not working?

The binding to the ItemsSource list is working. I can tell because the list contains four items and, when I test, my flyout menu also has four items. The problem is each MenuFlyoutItem is blank. In the code below, SourceForCompaniesList is an ObservableCollection of type Company. CompanyName is a string property of Company. I have successfully binded to this list in combo boxes, but I cannot make it work in the flyout menu. Can someone please tell me what I'm doing wrong?

<FlyoutBase.AttachedFlyout>
    <Flyout helpers:BindableFlyout.ItemsSource="{Binding ElementName=thePage, Path=DataContext.SourceForCompaniesList}" x:Name="theFlyout">
        <helpers:BindableFlyout.ItemTemplate>
            <DataTemplate>
                <MenuFlyoutItem Text="{Binding ElementName=theFlyout,Path=DataContext.CompanyName}" />
            </DataTemplate>                                                             
        </helpers:BindableFlyout.ItemTemplate>
    </Flyout>                                                       
</FlyoutBase.AttachedFlyout>

Screenshot of open menu:

Screenshot of open menu

Upvotes: 0

Views: 304

Answers (1)

Martin Zikmund
Martin Zikmund

Reputation: 39082

The item Text binding can be rewritten in a simpler way which should work correctly:

<FlyoutBase.AttachedFlyout>
    <Flyout helpers:BindableFlyout.ItemsSource="{Binding ElementName=thePage, Path=DataContext.SourceForCompaniesList}" x:Name="theFlyout">
        <helpers:BindableFlyout.ItemTemplate>
            <DataTemplate>
                <MenuFlyoutItem Text="{Binding CompanyName}" />
            </DataTemplate>                                                             
        </helpers:BindableFlyout.ItemTemplate>
    </Flyout>                                                       
</FlyoutBase.AttachedFlyout>

Note I am using just CompanyName, as the context of the DataTemplate is actually a single Company from the bound items source, so you are binding relative to the company item itself.

Note, to get an even better performance, you can use x:DataType and x:Bind:

<FlyoutBase.AttachedFlyout>
    <Flyout helpers:BindableFlyout.ItemsSource="{Binding ElementName=thePage, Path=DataContext.SourceForCompaniesList}" x:Name="theFlyout">
        <helpers:BindableFlyout.ItemTemplate>
            <DataTemplate x:DataType="YourXmlNamespace:Company">
                <MenuFlyoutItem Text="{x:Bind CompanyName}" />
            </DataTemplate>                                                             
        </helpers:BindableFlyout.ItemTemplate>
    </Flyout>                                                       
</FlyoutBase.AttachedFlyout>

Where you need to declare the YourXmlNamespace in the root element (most likely a Page) as a xmlns namespace. This version is more performant, as it uses compiled binding (x:Bind) instead of reflection-based Binding.

Upvotes: 1

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