Windows IoT Raspberry Pi 3 C# 枚举 USB 音频适配器

Question

我打算将 2 个或更多 USB 音频适配器（每个都带有麦克风和线路）连接到我的树莓派 3。因此我需要分别枚举音频渲染和音频捕获的音频设备并将它们显示在 listbox 类似到audioinsample。 我不明白这是怎么回事。 我尝试使用下面的代码，发生异常处理程序。 请指教。 谢谢。

        captureDeviceList = new ObservableCollection<DeviceInformation>();
        audioCaptureList.ItemsSource = captureDeviceList;

        renderDeviceList = new ObservableCollection<DeviceInformation>();
        audioRenderList.ItemsSource = renderDeviceList;


  private async void enumerateAudioDevice()
    {
        var renderDevices = await DeviceInformation.FindAllAsync(DeviceClass.AudioRender);

        if (renderDevices.Count > 0)
        {
            for (var i = 0; i < renderDevices.Count; i++)
            {
                renderDeviceList.Add(renderDevices[i]);
            }
            audioRenderList.SelectedItem = renderDevices[0];

        }


        var captureDevices = await DeviceInformation.FindAllAsync(DeviceClass.AudioCapture);
        if (captureDevices.Count > 0)
        {
            for (var i = 0; i < captureDevices.Count; i++)
            {
                captureDeviceList.Add(captureDevices[i]);
            }
            audioCaptureList.SelectedItem = captureDevices[0];

        }
    }

<PivotItem Header="Info">
            <Grid>
                <ListBox x:Name="audioRenderList" HorizontalAlignment="Left" Height="100" VerticalAlignment="Top" Width="288" Margin="0,25,0,0" FontSize="10"/>
                <ListBox x:Name="audioCaptureList" HorizontalAlignment="Left" Height="100" VerticalAlignment="Top" Width="288" Margin="318,25,0,0" FontSize="10"/>
                <TextBlock x:Name="renderDeviceCount" HorizontalAlignment="Left" Margin="248,0,0,0" TextWrapping="Wrap" Text="" VerticalAlignment="Top" Width="40"/>
                <TextBlock x:Name="captureDeviceCount" HorizontalAlignment="Left" Margin="566,0,0,0" TextWrapping="Wrap" Text="" VerticalAlignment="Top" Width="40" RenderTransformOrigin="0.425,-0.5"/>
                <TextBlock HorizontalAlignment="Left" Margin="318,0,0,0" TextWrapping="Wrap" Text="Capture Devices" VerticalAlignment="Top"/>
                <TextBlock HorizontalAlignment="Left" TextWrapping="Wrap" Text="Render Devices" VerticalAlignment="Top"/>
                <ListBox x:Name="usbList" HorizontalAlignment="Left" Height="100" Margin="0,158,0,0" VerticalAlignment="Top" Width="288"/>
                <TextBlock HorizontalAlignment="Left" TextWrapping="Wrap" Text="USB Devices" VerticalAlignment="Top" Margin="0,133,0,0"/>
                <TextBlock x:Name="usbDeviceCount" HorizontalAlignment="Left" TextWrapping="Wrap" Text="" VerticalAlignment="Top" Margin="248,133,0,0" Width="40"/>

            </Grid>
        </PivotItem>

更新： 我已经修改了我的 XAML 代码.. 它可以工作.. 但似乎我无法正确安排堆栈面板边距。

下面有我的代码。有什么建议吗？ 谢谢。

<PivotItem Header="Info">
            <Grid>
                <ListBox x:Name="audioRenderList" Margin="10,28,358,144" Width="250" Height="90">
                    <ListBox.ItemTemplate>
                        <DataTemplate x:DataType="device:DeviceInformation">
                            <StackPanel Orientation="Horizontal">
                                <TextBlock Text="{x:Bind Path=Name, Mode=OneWay}" Margin="0,0,0,0" FontSize="18"/>
                            </StackPanel>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
                <ListBox x:Name="audioCaptureList" Margin="344,28,10,144" Width="250" Height="90">
                    <ListBox.ItemTemplate>
                        <DataTemplate x:DataType="device:DeviceInformation">
                            <StackPanel Orientation="Horizontal">
                                <TextBlock Text="{x:Bind Path=Name, Mode=OneWay}" Margin="0,0,0,0" FontSize="18"/>
                            </StackPanel>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
                <TextBlock x:Name="renderDeviceCount" HorizontalAlignment="Left" Margin="220,4,0,0" TextWrapping="Wrap" Text="" VerticalAlignment="Top" Width="40"/>
                <TextBlock x:Name="captureDeviceCount" HorizontalAlignment="Left" Margin="560,4,0,0" TextWrapping="Wrap" Text="" VerticalAlignment="Top" Width="40" RenderTransformOrigin="0.425,-0.5"/>
                <TextBlock HorizontalAlignment="Left" Margin="350,4,0,0" TextWrapping="Wrap" Text="Capture Devices" VerticalAlignment="Top"/>
                <TextBlock HorizontalAlignment="Left" TextWrapping="Wrap" Text="Render Devices" VerticalAlignment="Top" Margin="10,4,0,0"/>
                <ListBox x:Name="usbList" Margin="10,156,358,16" Width="250" Height="90">
                    <ListBox.ItemTemplate>
                        <DataTemplate x:DataType="device:DeviceInformation">
                            <StackPanel Orientation="Horizontal">
                                <TextBlock Text="{x:Bind Path=Name, Mode=OneWay}" Margin="0,0,0,0" FontSize="18" />
                            </StackPanel>
                        </DataTemplate>
                    </ListBox.ItemTemplate>
                </ListBox>
                <TextBlock HorizontalAlignment="Left" TextWrapping="Wrap" Text="USB Storage" VerticalAlignment="Top" Margin="10,131,0,0"/>
                <TextBlock x:Name="usbDeviceCount" HorizontalAlignment="Left" TextWrapping="Wrap" Text="" VerticalAlignment="Top" Margin="220,131,0,0" Width="40" RenderTransformOrigin="0.575,-0.75"/>

            </Grid>
        </PivotItem>
    </Pivot>

2017 年 9 月 10 日更新

Answer 1

由于没有您在 xaml 中的代码，我不确定您的数据绑定方式。导致此问题的原因有多种。请参考下面的源代码，也许您需要进行一些修改以适合您的要求。此外，您应在页面标签中添加 xmlns:device="using:Windows.Devices.Enumeration"。

<Page
x:Class="AudioInSample.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:AudioInSample"
xmlns:device="using:Windows.Devices.Enumeration"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Grid Background="White">
    <StackPanel Margin="10" MinWidth="500">

        <ListBox x:Name="audioCaptureList">
            <ListBox.ItemTemplate>
                <DataTemplate  x:DataType="device:DeviceInformation">
                    <StackPanel>
                        <TextBlock Text="{x:Bind Path=Name, Mode=OneWay}" Margin="12, 15, 12, 0" FontSize="18.667" />
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>

        <ListBox x:Name="audioRenderList">
            <ListBox.ItemTemplate>
                <DataTemplate x:DataType="device:DeviceInformation">
                    <StackPanel>
                        <TextBlock Text="{x:Bind Path=Name, Mode=OneWay}" Margin="12, 15, 12, 0" FontSize="18.667" />
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>


    </StackPanel>
</Grid>