listview - 在 ListView Xamarin 表单中滚动时图像消失

Question

我有 xamarin 形式的 ListView。上下滚动此 ListView 时，此时钟图像的出现和消失不一致。

即使我对可见性进行硬编码，图像也不一致。

<DataTemplate x:Key="itemTemplate">
            <ViewCell>
                <StackLayout Orientation="Horizontal" Spacing="5" Padding="0,0,10,0">
                    <Label HorizontalOptions="StartAndExpand"  VerticalOptions="Center" TextColor="#455560" Text="{Binding DispenseTypeWithMachineCount}" WidthRequest="250"/>
                    <Image IsVisible="{Binding IsServiceInProgress}" Source="ic_progress.png" HeightRequest="24" WidthRequest="24" VerticalOptions="Center" HorizontalOptions="EndAndExpand"/>
                </StackLayout>
            </ViewCell>
        </DataTemplate>

<ListView x:Name="ListViewAccounts" Margin="0,0,0,0" ItemsSource="{Binding ExpandedGroups}" GroupDisplayBinding="{Binding Title}" IsGroupingEnabled="true" ItemTemplate="{StaticResource accountTemplateSelector}" GroupHeaderTemplate="{StaticResource groupHeaderTemplate}">
            <ListView.Behaviors>
                <behaviors:EventToCommandBehavior EventName="ItemTapped" Command="{Binding Path=BindingContext.ListViewAccountItemTappedCommand                               Source={x:Reference ListViewAccounts}}" />
            </ListView.Behaviors>
            <x:Arguments>
                <ListViewCachingStrategy>RecycleElement</ListViewCachingStrategy>
            </x:Argume

Answer 1

您还可以更改 ListView 回收元素的方式，我注意到您正在实现它，但您的看起来很奇怪:

策略类型:

• RetainElement//默认值

• RecycleElement

• RecycleElementAndDataTemplate

ListView :

<ListView
    x:Name="ListViewAccounts"
    Margin="0,0,0,0"
    ItemsSource="{Binding ExpandedGroups}"
    GroupDisplayBinding="{Binding Title}"
    IsGroupingEnabled="true"
    ItemTemplate="{StaticResource accountTemplateSelector}"
    CachingStrategy="RecycleElement"
    GroupHeaderTemplate="{StaticResource groupHeaderTemplate}">
    <ListView.Behaviors>
        <behaviors:EventToCommandBehavior
            EventName="ItemTapped"
            Command="{Binding Path=BindingContext.ListViewAccountItemTappedCommand,  Source={x:Reference ListViewAccounts}}" />
    </ListView.Behaviors>
</ListView>