Windows Phone 8.1中的ContentDialog无法正常关闭，即使它已隐藏

Question

我的Universal WP8应用程序中有几个ContentDialog。问题是，当我刚刚在页面A上使用一个并且我导航到页面B并尝试使用第二个时，我的应用程序崩溃并出现错误WINRT：一次只能打开一个ContentDialog。

我没有使用基本按钮，但我自己用命令实现了按钮，如下所示。

    <ContentDialog x:Name="contentDialog"
x:Class="ThuisApp.Content.PostComment"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:ThuisApp.Content"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Title="Post comment" DataContext="{Binding PostCommentViewmodel, Mode=OneWay, Source={StaticResource ViewmodelLocator}}" Foreground="{StaticResource MainAspectColor}" FullSizeDesired="True">

<Grid Margin="0">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition/>
    </Grid.RowDefinitions>

    <StackPanel VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
        <Grid Margin="0,0,0,12">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto"/>
                <ColumnDefinition Width="12"/>
                <ColumnDefinition/>
                <ColumnDefinition Width="Auto"/>
            </Grid.ColumnDefinitions>
            <Border HorizontalAlignment="Left" Height="50" Margin="0" VerticalAlignment="Top" Width="50" BorderBrush="{StaticResource MainAspectColor}" BorderThickness="1" >
                <Grid>
                    <Image Source="ms-appx:///Assets/profile-placeholder.png"/>
                    <Image Source="{Binding Report.userID, Converter={StaticResource UserIdToImageUrlConverter}}"/>
                </Grid>
            </Border>
            <TextBlock HorizontalAlignment="Left" Text="{Binding Report.username}" VerticalAlignment="Top" FontFamily="{StaticResource ReportUserFont}" FontSize="{StaticResource ReportUserFontSize}" TextTrimming="CharacterEllipsis" Margin="0" Grid.Column="2" Foreground="{StaticResource ReportHeaderTextColor}"/>
            <TextBlock HorizontalAlignment="Right" TextWrapping="Wrap" Text="{Binding Report.createDate, Converter={StaticResource TimePassedConverter}}" VerticalAlignment="Top" FontSize="{StaticResource ReportHeaderInfoFontSize}" FontFamily="{StaticResource ReportHeaderInfoFont}" FontWeight="Light" Grid.Column="3" Foreground="{StaticResource ReportHeaderTextColor}"/>
        </Grid>
        <TextBlock x:Name="body" Style="{StaticResource MessageDialogContentStyle}" TextWrapping="Wrap" MaxHeight="140" TextTrimming="WordEllipsis" Text="{Binding Report.Message}" FontFamily="{StaticResource ItemBodyFont}" FontSize="{StaticResource ItemBodyFontSize}" Foreground="{StaticResource ItemBodyTextColor}"/>
        <TextBox Header="Comment" TextWrapping="Wrap" MinHeight="140" Text="{Binding Comment, Mode=TwoWay}" HeaderTemplate="{StaticResource TextBoxHeader}" SelectionHighlightColor="{StaticResource TextBoxSelectionHighlightColor}"/>
        <!-- Content body -->
    </StackPanel>
    <Grid VerticalAlignment="Bottom" Grid.Row="1" Margin="0,12,0,0">
        <Grid.ColumnDefinitions>
            <ColumnDefinition/>
            <ColumnDefinition/>
        </Grid.ColumnDefinitions>
        <Button Content="post comment" HorizontalAlignment="Stretch" VerticalAlignment="Top" Margin="0,0,12,0" Style="{StaticResource FullColorButton}" Background="#FF42A5F5" Foreground="White" Command="{Binding PostComment}"/>
        <Button Content="cancel" HorizontalAlignment="Stretch" VerticalAlignment="Top" Margin="12,0,0,0" Style="{StaticResource FullColorButton}" Background="#FF42A5F5" Foreground="White" Grid.Column="1" Command="{Binding Cancel}"/>
    </Grid>
</Grid>

我通过使用Galasoft的Messenger向View发送消息来处理Init和关闭。

    public Constructor
     Messenger.Default.Register<bool>(true, MessengerToken.OpenClosePostCommentPopup, OpenClosePostCommentPopup);
    }

    public async void OpenClosePostCommentPopup(bool isOpen)
    {
        if (isOpen && !_isDialogOpen)
        {
            _dialog = new PostComment();
            _dialog.Opened += dialog_Opened;
            _dialog.Closed += dialog_Closed;
            await _dialog.ShowAsync();
        }
        else
        {
            _dialog.Hide();
            _dialog = null;
        }
    }

    void dialog_Closed(ContentDialog sender, ContentDialogClosedEventArgs args)
    {
        _isDialogOpen = false;
    }

    void dialog_Opened(ContentDialog sender, ContentDialogOpenedEventArgs args)
    {
        _isDialogOpen = true;
    }

我知道它击中了.Hide而且它隐藏了，但由于某种原因，它仍然认为它是以某种方式打开的。有没有人有任何想法？

按要求：下面是调用打开框的命令

PostComment = new RelayCommand<ReportDB>(item =>
        {
            //Load information into VM
            Messenger.Default.Send<ReportDB>(item, MessengerToken.LoadReportToComment);
            //Opens the popup
            Messenger.Default.Send<bool>(true, MessengerToken.OpenClosePostCommentPopup);
        });

Answer 1

我在带有问题鼠标的Windows 10 Universal App上遇到了同样的问题（双击）。因此，如果双击该按钮，将显示第一个对话框，但已阻止第二个对话框。因此解决方案是不要同时打开两个ContentDialog。

这是我的解决方案，以避免异常：

    private static List<MessageDialog> dialogOpenQueue = new List<MessageDialog>();
    public string Message { get; set; }
    public MessageDialog()
    {
        this.InitializeComponent();
    }

    private static bool quickShowRunning = false;

    public async static Task QuickShowAsync(string title, string message)
    {
        MessageDialog dialog = new MessageDialog() { Title = title, Message = message };
        dialogOpenQueue.Add(dialog);
        if (quickShowRunning)
            return;
        quickShowRunning = true;

        for (int i = 0; i< dialogOpenQueue.Count; i++)
        {
            await dialogOpenQueue[i].ShowAsync();
            dialogOpenQueue.RemoveAt(i);
            i--;
        }
        quickShowRunning = false;
    }

Answer 2

如果您想从您提交的特定对话框中获取结果，并避免显式排队和循环，请尝试"Only a single ContentDialog can be open at any time." error while opening another contentdialog中的方法