C# UWP：参数不正确-NavigationView

Question

I'm building a UWP in C# with Visual Studio, and need to hide and show a NavigationView, named 'navigationView' as required. I am using the property .IsPaneVisible to achieve this, but am encountering a strange bug:

I can set IsPaneVisible = true or false in the xaml document, but if I set navigationView.IsPaneVisible = false; in the related C# document, and run a debug build of the app from Visual Studio, the app crashes with the error

System.ArgumentException: 'The parameter is incorrect.

Even stranger, if I run the same debug build, but launched directly, outside Visual Studio, the app functions normally without crashing at this line.

Does anyone have an idea of why this might be happening or how I could fix it?

Here's the xaml code:

<Page
    x:Class="Sheet_Music_Reader.Views.ShellPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:i="using:Microsoft.Xaml.Interactivity"
    xmlns:behaviors="using:Sheet_Music_Reader.Behaviors"
    xmlns:winui="using:Microsoft.UI.Xaml.Controls"
    xmlns:helpers="using:Sheet_Music_Reader.Helpers"
    xmlns:views="using:Sheet_Music_Reader.Views"
    Loaded="OnLoaded"
    mc:Ignorable="d">
    <Page.Resources>
        <!--This top margin is the height of the custom TitleBar-->
        <Thickness x:Key="NavigationViewContentMargin">0,48,0,0</Thickness>
        <Thickness x:Key="NavigationViewContentGridBorderThickness">0</Thickness>
        <SolidColorBrush x:Key="NavigationViewContentBackground" Color="Transparent"></SolidColorBrush>
    </Page.Resources>

    <Grid>
        <Border x:Name="AppTitleBar"
                IsHitTestVisible="True"
                VerticalAlignment="Top"
                Background="Transparent"
                Height="40"
                Canvas.ZIndex="1" 
                Margin="48,8,0,0">
            <StackPanel Orientation="Horizontal">
                <Image x:Name="AppFontIcon"
                    HorizontalAlignment="Left" 
                    VerticalAlignment="Center"
                    Source="Assets/Square44x44Logo.png" 
                    Width="16" 
                    Height="16"/>
                <TextBlock x:Name="AppTitle"
                    Text="enScore"
                    VerticalAlignment="Center"
                    Margin="12,0,0,0"
                    Style="{ThemeResource CaptionTextBlockStyle}"/>
            </StackPanel>
        </Border>

        <winui:NavigationView
            IsBackButtonVisible="Visible"
            IsBackEnabled="{x:Bind IsBackEnabled, Mode=OneWay}"
            SelectedItem="{x:Bind Selected, Mode=OneWay}"
            ItemInvoked="OnItemInvoked"
            IsSettingsVisible="True"
            IsTitleBarAutoPaddingEnabled="False"
            DisplayModeChanged="NavigationViewControl_DisplayModeChanged"
            Canvas.ZIndex="0"
            x:Name="navigationView">
            <winui:NavigationView.MenuItems>
              
                <winui:NavigationViewItem x:Uid="Shell_Main" Icon="Copy" helpers:NavHelper.NavigateTo="views:MainPage" />
                
            </winui:NavigationView.MenuItems>

            <i:Interaction.Behaviors>
                <behaviors:NavigationViewHeaderBehavior
                DefaultHeader="{x:Bind Selected.Content, Mode=OneWay}">
                    <behaviors:NavigationViewHeaderBehavior.DefaultHeaderTemplate>
                        <DataTemplate>
                            <Grid x:Name="headerGrid">
                                <TextBlock
                                Text="{Binding}"
                                Style="{ThemeResource TitleTextBlockStyle}"
                                Margin="{StaticResource SmallLeftRightMargin}" />
                                <Button Style="{ThemeResource ButtonRevealStyle}"  Content="Refresh Library Contents" HorizontalAlignment="Right" Margin="0,45,8,0" Click="RefreshLibrary"/>
                                <Button Style="{ThemeResource ButtonRevealStyle}" Content="Import PDF To Current Folder" HorizontalAlignment="Right" Margin="0,-35,140,0" Click="AddScore"/>
                                <Button Style="{ThemeResource ButtonRevealStyle}" Content="Add New Folder" HorizontalAlignment="Right" Margin="0,-35,8,0" Click="AddFolderAsync"/>
                                <ToggleButton Style="{ThemeResource ToggleButtonRevealStyle}"  x:FieldModifier="public" x:Name="tbtndelete" Content="Delete Items" HorizontalAlignment="Right" Margin="0,45,191,0" Tapped="DeleteItem"/>
                            </Grid>
                        </DataTemplate>
                    </behaviors:NavigationViewHeaderBehavior.DefaultHeaderTemplate>
                </behaviors:NavigationViewHeaderBehavior>
            </i:Interaction.Behaviors>
            <Grid>
                <Frame x:Name="shellFrame" />
            </Grid>
        </winui:NavigationView>
      
    </Grid>

    
</Page>

Answer 1

Try to change the placement of the menu with:

PaneDisplayMode="Top"

For my case with Microsoft.UI.Xaml.Controls for Microsoft.WindowsAppSDK v1.0.0. the showing/hidding of menu bar works fine.

Left, LeftMinimal, LeftCompact crashes the app. I know you may expect the menu on the left, but still on the top is not that bad idea;-) At least it works.. Greetz.