Raspberry Pi作为录音机赢得10项物联网

时间：2018-10-31 14:25:11

标签： c# raspberry-pi3 windows-10-iot-core

设备：Raspberry PI 3 操作系统：WIN 10 IOT 编程语言：C＃

我正在尝试对24/7记录器进行编程，以便稍后在Raspberry打开时记录所有内容。 音频文件的长度应在30分钟后。 然后，文件将按年，月，日存储在文件夹中的USB记忆棒中。 在USB记忆棒上创建文件夹已经可以。

我的问题是文件已创建但没有内容。 该文件的大小为0kb。 这是代码。

感谢您的帮助。

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Devices.Enumeration;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.Media.Capture;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using System.Collections.ObjectModel;
using System.Threading.Tasks;
using Windows.Media.MediaProperties;
using Windows.Media.Playback;
using Windows.Storage;
using Windows.Storage.Streams;

namespace Recording_PI
{
    /// <summary>
    /// Eine leere Seite, die eigenständig verwendet oder zu der innerhalb eines Rahmens navigiert werden kann.
    /// </summary>
    public sealed partial class MainPage : Page
    {
        bool isRecording;
        LowLagMediaRecording audioRecording;
        MediaCapture audioCapture = new MediaCapture();

        public MainPage()
        {
            this.InitializeComponent();

            Checked();
            Task.Delay(10000).Wait();    
            Unchecked();


        }

        private async void Checked()
        {
            var settings = new Windows.Media.Capture.MediaCaptureInitializationSettings();
            settings.StreamingCaptureMode = Windows.Media.Capture.StreamingCaptureMode.Audio;
            settings.MediaCategory = Windows.Media.Capture.MediaCategory.Other;
            settings.AudioProcessing = Windows.Media.AudioProcessing.Default;
            await audioCapture.InitializeAsync(settings);

            StorageFolder externalDevices = KnownFolders.RemovableDevices;
            IReadOnlyList<StorageFolder> externalDrives = await externalDevices.GetFoldersAsync();
            StorageFolder usbStorage = externalDrives[0];

            //ENSURE FOLDER EXISTS
            if (await usbStorage.TryGetItemAsync("Recording") == null)
                await usbStorage.CreateFolderAsync("Recording");

            string Folder_Pfad = "Recording\\" + DateTime.Now.Year.ToString();
            if (await usbStorage.TryGetItemAsync(Folder_Pfad) == null)
                await usbStorage.CreateFolderAsync(Folder_Pfad);

            Folder_Pfad = Folder_Pfad + "\\" + DateTime.Now.Month.ToString();
            if (await usbStorage.TryGetItemAsync(Folder_Pfad) == null)
                await usbStorage.CreateFolderAsync(Folder_Pfad);

            Folder_Pfad = Folder_Pfad + "\\" + DateTime.Now.Day.ToString();
            if (await usbStorage.TryGetItemAsync(Folder_Pfad) == null)
                await usbStorage.CreateFolderAsync(Folder_Pfad);

            string Dateiname = "\\" + DateTime.Now.Year.ToString() + "-" + DateTime.Now.Month.ToString() + "-" + DateTime.Now.Day.ToString() + " "
                 + DateTime.Now.Hour.ToString() + "_" + DateTime.Now.Minute.ToString() + "_" + DateTime.Now.Second.ToString()+ ".mp3";

            string Dateispeicher_Ort = Folder_Pfad + Dateiname;

            StorageFile recordFile = await usbStorage.CreateFileAsync(Dateispeicher_Ort, Windows.Storage.CreationCollisionOption.GenerateUniqueName);

            await audioCapture.StartRecordToStorageFileAsync(MediaEncodingProfile.CreateMp3(AudioEncodingQuality.Medium), recordFile);

        }


        private async void Unchecked()
        {
            if (isRecording)
            {
                await audioCapture.StopRecordAsync();
            }

        }

    }
}

1 个答案:

答案 0 :(得分：0)

  

我的问题是文件已创建但没有内容。的   文件大小为0kb。

这是因为，当您的代码在具有Windows IoT核心版的Raspberry Pi上运行时，以下行将导致异常，因此该文件尚未写入内容。如果您调试应用程序，则将由于此异常而终止。

var myarray = [ {name:"Nita",id:"001"}, {name:"Lyda",id:"002"}, {name:"Lika",id:"003"} ]; var result = myarray.filter( x => x.name.includes("L")).map( x => x.id) console.log(result)

您需要使用以下行而不是上面的行：

await audioCapture.StartRecordToStorageFileAsync(MediaEncodingProfile.CreateMp3(AudioEncodingQuality.Auto), recordFile);

引用：“ MediaCapture.PrepareLowLagRecordToStorageFileAsync”

您的代码中还有其他问题。

  1. var audioRecording = await audioCapture.PrepareLowLagRecordToStorageFileAsync(MediaEncodingProfile.CreateM4a(AudioEncodingQuality.Auto), recordFile); await audioRecording.StartAsync(); 变量从未启动或未分配任何值，因此它始终为isRecording。因此，此行可能永远不会执行：false
  2. await audioCapture.StopRecordAsync();方法可能在Unchecked()函数完成之前执行，因为在Checked()方法中您使用Checked()，因此将继续执行代码，然后执行await和Task.Delay(10000).Wait();。在这种情况下，音频将在开始之前停止。

另一个建议是在代码中添加try-catch，以便您可以在应用终止之前处理异常。

首先，我对您的代码进行了一些编辑。以下是您可以尝试查看是否有帮助的完整代码。

MainPage.xaml： 

Unchecked();

MainPage.xaml.cs： 

<Page
    x:Class="Recording_PI.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Recording_PI"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <StackPanel VerticalAlignment="Center">
        <TextBlock Name="Result" Text="" />
    </StackPanel>
</Page>

package.appxmanifest中的功能： 

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Devices.Enumeration;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.Media.Capture;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using System.Collections.ObjectModel;
using System.Threading.Tasks;
using Windows.Media.MediaProperties;
using Windows.Media.Playback;
using Windows.Storage;
using Windows.Storage.Streams;
using Windows.ApplicationModel.Core;
using Windows.UI.Core;

namespace Recording_PI
{
    /// <summary>
    /// Eine leere Seite, die eigenständig verwendet oder zu der innerhalb eines Rahmens navigiert werden kann.
    /// </summary>
    public sealed partial class MainPage : Page
    {
        bool isRecording;
        LowLagMediaRecording audioRecording;
        MediaCapture audioCapture = new MediaCapture();

        public MainPage()
        {
            this.InitializeComponent();

            Checked();


        }

        private async void Checked()
        {
            try
            {
                var settings = new Windows.Media.Capture.MediaCaptureInitializationSettings();
                settings.StreamingCaptureMode = Windows.Media.Capture.StreamingCaptureMode.Audio;
                settings.MediaCategory = Windows.Media.Capture.MediaCategory.Other;
                settings.AudioProcessing = Windows.Media.AudioProcessing.Default;
                await audioCapture.InitializeAsync(settings);

                StorageFolder externalDevices = KnownFolders.RemovableDevices;
                IReadOnlyList<StorageFolder> externalDrives = await externalDevices.GetFoldersAsync();
                StorageFolder usbStorage = externalDrives[0];

                //ENSURE FOLDER EXISTS
                if (await usbStorage.TryGetItemAsync("Recording") == null)
                    await usbStorage.CreateFolderAsync("Recording");

                string Folder_Pfad = "Recording\\" + DateTime.Now.Year.ToString();
                if (await usbStorage.TryGetItemAsync(Folder_Pfad) == null)
                    await usbStorage.CreateFolderAsync(Folder_Pfad);

                Folder_Pfad = Folder_Pfad + "\\" + DateTime.Now.Month.ToString();
                if (await usbStorage.TryGetItemAsync(Folder_Pfad) == null)
                    await usbStorage.CreateFolderAsync(Folder_Pfad);

                Folder_Pfad = Folder_Pfad + "\\" + DateTime.Now.Day.ToString();
                if (await usbStorage.TryGetItemAsync(Folder_Pfad) == null)
                    await usbStorage.CreateFolderAsync(Folder_Pfad);

                string Dateiname = "\\" + DateTime.Now.Year.ToString() + "-" + DateTime.Now.Month.ToString() + "-" + DateTime.Now.Day.ToString() + " "
                     + DateTime.Now.Hour.ToString() + "_" + DateTime.Now.Minute.ToString() + "_" + DateTime.Now.Second.ToString() + ".mp3";

                string Dateispeicher_Ort = Folder_Pfad + Dateiname;

                StorageFile recordFile = await usbStorage.CreateFileAsync(Dateispeicher_Ort, Windows.Storage.CreationCollisionOption.GenerateUniqueName);

                isRecording = true;
                //await audioCapture.StartRecordToStorageFileAsync(MediaEncodingProfile.CreateMp3(AudioEncodingQuality.Auto), recordFile);

                var audioRecording = await audioCapture.PrepareLowLagRecordToStorageFileAsync(MediaEncodingProfile.CreateM4a(AudioEncodingQuality.Medium), recordFile);
                await audioRecording.StartAsync();

                Task.Delay(10000).Wait();
                Unchecked();
            }
            catch (Exception ex)
            {
                await CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, ()=> {
                    Result.Text += ex.Message;
                });

            }

        }


        private async void Unchecked()
        {
            if (isRecording)
            {
                await audioCapture.StopRecordAsync();
            }

        }

    }
}
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