未调用Xamarin.Forms.Mac命令

我有一个带有ListView的页面,其中显示了一些包含音频数据的单元格。

<?xml version="1.0" encoding="UTF-8"?>
<ViewCell xmlns="http://xamarin.com/schemas/2014/forms"
   xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
   xmlns:audioViews="clr-namespace:Lama.Forms.Source.UI.CustomControls.AudioViews;assembly=Lama.Forms"
   x:Class="Lama.Forms.Source.UI.Pages.MainPages.MacOSAudiofileCellView"
   Padding="0" HasShadow="False" >

<StackLayout BackgroundColor="{Binding BackgroundColor}" Orientation="Vertical" Margin="0,2,0,2" Spacing="0">
    <StackLayout.GestureRecognizers>
        <TapGestureRecognizer Command="{Binding SelectCellCommand}" />
    </StackLayout.GestureRecognizers>

    <Grid RowSpacing="0" ColumnSpacing="0" VerticalOptions="FillAndExpand" Margin="0,0,0,5">
        <Grid.RowDefinitions>
            <RowDefinition Height="75" />
            <RowDefinition Height="75" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="10" />
            <ColumnDefinition Width="75" />
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>

...

        <!-- The Playback Buttons -->
        <Grid Grid.Row="1" Grid.Column="1">

            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*" />
                <ColumnDefinition Width="*" />
            </Grid.ColumnDefinitions>

            <!-- Play Button -->
            <Image Source="{Binding PlayButtonIcon}">
                <Image.GestureRecognizers>
                    <TapGestureRecognizer Command="{Binding PlayCommand}" />
                </Image.GestureRecognizers>
            </Image>

            <!-- Stop Button -->
            <Image Source="{Binding StopButtonIcon}" Grid.Column="1">
                <Image.GestureRecognizers>
                    <TapGestureRecognizer Command="{Binding StopCommand}" />
                </Image.GestureRecognizers>
            </Image>
        </Grid>

        <!-- The Grid for Filename, Artist and Title -->
        <Grid Grid.Row="0" Grid.Column="2" Grid.ColumnSpan="2" RowSpacing="0" ColumnSpacing="0">
            <Grid.RowDefinitions>
                <RowDefinition Height="*" />
                <RowDefinition Height="*" />
            </Grid.RowDefinitions>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*" />
                <ColumnDefinition Width="*" />
            </Grid.ColumnDefinitions>

            <!-- The Filename -->
            <StackLayout Grid.ColumnSpan="2" Margin="10,0,0,0"
                         Orientation="Horizontal" VerticalOptions="Fill">

                <Label Text="Filename:"
                       VerticalTextAlignment="Center"
                       WidthRequest="100"
                       VerticalOptions="Fill"
                       Style="{StaticResource CellLabel}" />

                <Label x:Name="LblFilename" Text="{Binding Filename}"
                       VerticalTextAlignment="Center"
                       VerticalOptions="Fill"
                       Style="{StaticResource CellLabel}"/>

                <StackLayout.GestureRecognizers>
                    <TapGestureRecognizer Command="{Binding ChooseNewFilenameCommand}"/>
                </StackLayout.GestureRecognizers>

            </StackLayout>

            <!-- The Artist -->
            <StackLayout Grid.Row="1" Grid.Column="0" Margin="10,0,0,0" Orientation="Horizontal">
                <StackLayout.GestureRecognizers>
                    <TapGestureRecognizer Command="{Binding ChooseNewArtistCommand}"/>
                </StackLayout.GestureRecognizers>
                <Label Text="Artist:"
                               WidthRequest="100"
                               VerticalTextAlignment="Center" 
                               Style="{StaticResource CellLabel}"/>

                <Label Text="{Binding Artist}"
                           VerticalTextAlignment="Center"
                           Style="{StaticResource CellLabel}"/>
            </StackLayout>

            ...
</ViewCell>

public class AudiofileCellViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged = delegate { };

    #region Commands
    public Command SelectCellCommand { get; }
    public Command ChooseNewFilenameCommand { get; }
    public Command ChooseNewArtistCommand { get; }

    public Command PlayCommand { get; }
    public Command StopCommand { get; }
    #endregion

    #region CTOr
    protected BaseAudiofileCellViewModel()
    {
        SelectCellCommand = new Command(SelectCell);
        ChooseNewFilenameCommand = new Command(async () => await ChooseNewFilename());
        ChooseNewArtistCommand = new Command(ChooseNewArtist);
        ChooseNewTitleCommand = new Command(ChooseNewTitle);
        ChooseNewAlbumCommand = new Command(ChooseNewAlbum);
        ChooseNewCommentCommand = new Command(ChooseNewComment);
        ChooseNewKeyCommand = new Command(ChooseNewKey);
        ChooseNewBpmCommand = new Command(ChooseNewBpm);

        PlayCommand = new Command(async () => await PlayAudiofile());
        StopCommand = new Command(StopAllAudiofiles);
    }
    #endregion

有一些为标签定义的命令将在点击时调用。这对Xamarin.Forms.UWP有效,但如果切换到Xamarin.Forms.Mac,它们就不会启动。我可以通过主页上的一个动画视图看到发生了一些事情,它在单击时会结巴,但从来没有断点被击中。 我正在运行最新的稳定:Xamarin.Forms 3.1.0.697729