MAUI绑定ObservableCOllection<string>到ListView抛出System.Runtime.InteropServices.COMException
MAUI绑定ObservableCOllection<string>到ListView抛出System.Runtime.InteropServices.COMException
提问于 2022-06-11 00:02:09
在我的页面中添加一个ListView将引发运行时异常，当我试图使用Shell.Current.Navigation.PushModalAsync(new CollectionItemDetails(item));导航到该页面时，我想知道我是否以某种方式修改了XAML，或者我的绑定是否关闭，因为删除列表视图可以防止异常发生。
列表视图XAML参见Listview在底部
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="CollectionItemDetails"
xmlns:ViewModels="clr-namespaceViewModels"
Title="{Binding Item.Name}">
<ContentPage.BindingContext>
<ViewModels:CollectionItemDetailsViewModel/>
</ContentPage.BindingContext>
<StackLayout>
<!--Header Display-->
<FlexLayout HorizontalOptions="{OnPlatform WinUI=Start, Default=Center}"
VerticalOptions="Fill"
Wrap="Wrap">
<!--Image-->
<Frame CornerRadius="45"
HeightRequest="300"
WidthRequest="300"
HasShadow="False">
<Image Source="{Binding Item.Image}"
HeightRequest="300"
MinimumWidthRequest="300"
Margin="-20"
Aspect="AspectFill"/>
</Frame>
<StackLayout HorizontalOptions="{OnPlatform WinUI=StartAndExpand, Default=Center}">
<Label Text="{Binding Item.Name}"
FontSize="{OnPlatform WinUI=Header, Default=Title}"
FontAttributes="Bold"
HorizontalOptions="Center"/>
<Grid ColumnSpacing="50"
HorizontalOptions="Center">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<!--PlayerCount-->
<HorizontalStackLayout Grid.Column="0"
HorizontalOptions="Start">
<Label VerticalOptions="Center" FontSize="Small">
<Label.FormattedText>
<FormattedString>
<Span Text="{Binding Item.MinPlayers}"/>
<Span Text="-"/>
<Span Text="{Binding Item.MaxPlayers}"/>
</FormattedString>
</Label.FormattedText>
</Label>
<Image x:Name="PlayerCountIMG"
Source="{AppThemeBinding Light=players.png, Dark=playerswhite.png}"
HeightRequest="30" WidthRequest="30"/>
</HorizontalStackLayout>
<!--Playtime-->
<HorizontalStackLayout Grid.Column="1"
HorizontalOptions="Center">
<Label VerticalOptions="Center" FontSize="Small" Text="{Binding Item.PlayTime}"/>
<Image Source="clock.png" HeightRequest="30" WidthRequest="30"/>
</HorizontalStackLayout>
<!--Age-->
<HorizontalStackLayout Grid.Column="2"
HorizontalOptions="End">
<Label VerticalOptions="Center" FontSize="Small">
<Label.FormattedText>
<FormattedString>
<Span Text="{Binding Item.MinAge}"/>
<Span Text="+"/>
</FormattedString>
</Label.FormattedText>
</Label>
<Image Source="{AppThemeBinding Light=age.png, Dark=agewhite.png}" HeightRequest="30" WidthRequest="30"/>
</HorizontalStackLayout>
<Label Grid.Column="3"
VerticalOptions="Center">
<Label.FormattedText>
<FormattedString>
<Span Text="Weight: "
FontAttributes="Bold"/>
<Span Text="{Binding Item.Statistics.Ratings.AverageWeights.Value, StringFormat='{0:F2}'}"
TextColor="Orange"
FontAttributes="Bold"/>
</FormattedString>
</Label.FormattedText>
</Label>
</Grid>
<!--Publishers This is causing the breakage-->
<ListView BindingContext="{Binding Publishers}">
<ListView.ItemTemplate>
<DataTemplate>
<TextCell Text="{Binding}"/>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
<!--<ListView BindingContext="{Binding Source={RelativeSource Self}, Path=Item.Publishers}">
<ListView.ItemTemplate>
<DataTemplate>
<Label Text="{Binding .}"/>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>-->
</StackLayout>
</FlexLayout>
<Label Text="{Binding Item.Description}"
TextType="Html"/>
</StackLayout>
</ContentPage>代码在中的应用
public partial class CollectionItemDetails : ContentPage
{
public ICollectionItemDetailsViewModel itemViewModel;
public CollectionItemDetails(CollectionPageItem item)
{
InitializeComponent();
Init(item);
}
private void Init(CollectionPageItem item)
{
itemViewModel = BootStrapper.Resolve<ICollectionItemDetailsViewModel>(new[] { new NamedParameter("item", item) });
BindingContext = itemViewModel;
}
}ViewModel
public class CollectionItemDetailsViewModel : ViewModelBase, ICollectionItemDetailsViewModel
{
public CollectionItemDetailsViewModel()
{
}
public CollectionItemDetailsViewModel(CollectionPageItem item)
{
Item = item;
Publishers = Item.Publishers.ToObservableCollection();
}
public CollectionPageItem Item { get; private set; }
private ObservableCollection<string> _publishers = new();
public ObservableCollection<string> Publishers
{
get => _publishers;
private set { _publishers = value; OnPropertyChanged(nameof(Publishers)); }
}
}我最初试图将ListView绑定到Item.Publishers属性(这是一个IList<string> )，但由于异常，我试图将该属性公开为ObservableCollection<string>，尽管这个页面实际上并不需要监视更改。不幸的是，还是有例外。
异常详细信息
System.Runtime.InteropServices.COMException
HResult=0x88000FA8
Message=0x88000FA8
Source=WinRT.Runtime
StackTrace:
at WinRT.ExceptionHelpers.<ThrowExceptionForHR>g__Throw|20_0(Int32 hr)
at ABI.Microsoft.UI.Xaml.Controls.INavigationView2.global::Microsoft.UI.Xaml.Controls.INavigationView2.set_PaneDisplayMode(NavigationViewPaneDisplayMode value)
at Microsoft.UI.Xaml.Controls.NavigationView.set_PaneDisplayMode(NavigationViewPaneDisplayMode value)
at Microsoft.Maui.Controls.Handlers.ShellItemHandler.MapTabBarIsVisible(ShellItemHandler handler, ShellItem item)
at Microsoft.Maui.Controls.Shell.SendNavigated(ShellNavigatedEventArgs args)
at Microsoft.Maui.Controls.Shell.<.ctor>b__169_0(Object _, ShellNavigatedEventArgs args)
at Microsoft.Maui.Controls.ShellNavigationManager.<>c__DisplayClass15_0.<HandleNavigated>g__FireNavigatedEvents|1(ShellNavigatedEventArgs a, Shell shell)
at Microsoft.Maui.Controls.ShellNavigationManager.<>c__DisplayClass15_0.<HandleNavigated>b__0()
at Microsoft.Maui.Controls.Page.OnAppearing(Action action)
at Microsoft.Maui.Controls.BaseShellItem.OnAppearing(Action action)
at Microsoft.Maui.Controls.ShellNavigationManager.HandleNavigated(ShellNavigatedEventArgs args)
at Microsoft.Maui.Controls.ShellNavigationManager.<GoToAsync>d__14.MoveNext()
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
at Microsoft.Maui.Controls.ShellSection.NavigationImpl.<OnPushModal>d__8.MoveNext()
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
at Microsoft.Maui.Controls.Shell.NavigationImpl.<OnPushModal>d__11.MoveNext()
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
at ..\.CollectionViewModel.<ItemTapped>d__17.MoveNext() in C:\ViewModels\CollectionViewModel.cs:line 114回答 1
Stack Overflow用户
发布于 2022-06-11 02:23:46
<TextCell Text="{Binding}"/>看上去像个打字错误。这是无效的语法。
你可能是说：
<TextCell Text="{Binding .}"/>
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/72580776
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