Sharpnado Tabs首个Tab无显示：DelayedView内布局改Grid引发

在TabSwitcher中使用DelayedView组件，将DelayedView内部的布局从FlexLayout修改为Grid后，第一个Tab完全无法显示内容；但切换至后续标签页时，同类型的新DelayedView对象却能正常展示内容，且无异常抛出或Logcat日志输出。

重现步骤 #

TabViewSwitcher代码：

<tabs:ViewSwitcher x:Name="Switcher"
                   Animate="True"
                   SelectedIndex="{Binding SelectedViewModelIndex, Mode=TwoWay}">

    <tabs:DelayedView x:TypeArguments="contentViews:LobiPageView"
                      AccentColor="White"
                      BindingContext="{Binding Page1ViewModel}"
                      Animate="True"
                      UseActivityIndicator="True" />
    <tabs:DelayedView x:TypeArguments="contentViews:LobiPageView"
                      BindingContext="{Binding Page2ViewModel}"
                      AccentColor="{StaticResource Primary}"
                      Animate="True"
                      UseActivityIndicator="True" />
    <tabs:DelayedView x:TypeArguments="contentViews:LobiPageView"
                      BindingContext="{Binding Page3ViewModel}"
                      AccentColor="{StaticResource Primary}"
                      Animate="True"
                      UseActivityIndicator="True" />
    <tabs:DelayedView x:TypeArguments="contentViews:LobiPageView"
                      BindingContext="{Binding Page4ViewModel}"
                      AccentColor="{StaticResource Primary}"
                      Animate="True"
                      UseActivityIndicator="True" />
    <tabs:DelayedView x:TypeArguments="contentViews:LobiPageView"
                      BindingContext="{Binding Page5ViewModel}"
                      AccentColor="{StaticResource Primary}"
                      Animate="True"
                      UseActivityIndicator="True" />

</tabs:ViewSwitcher>

DelayedView ContentView代码：

<StackLayout>
    <Grid BindableLayout.ItemsSource="{Binding PageItems}" >

        <Grid.RowDefinitions>
            <RowDefinition></RowDefinition>
            <RowDefinition></RowDefinition>
            <RowDefinition></RowDefinition>
            <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition></ColumnDefinition>
            <ColumnDefinition></ColumnDefinition>
            <ColumnDefinition></ColumnDefinition>
            <ColumnDefinition></ColumnDefinition>
            <ColumnDefinition></ColumnDefinition>
        </Grid.ColumnDefinitions>
        <BindableLayout.ItemTemplate>
            <DataTemplate>
....
</DataTemplate>
</Grid>
</stackLayout>

截图说明 #

• 第一个Tab无内容显示：
  

• 第二个同类型Tab正常显示内容：
  

内容的提问来源于stack exchange，提问作者Cruik