从IP摄像机获取BitMap图像

Question

我想用RaspberryPI3从IP摄像头获取图像，我写了这段代码，但当我点击按钮时，系统就会宕机，在App.g.i.cs中抛出一个异常，我该如何修复该代码？

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.Storage.Streams;
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.Media.Imaging;
using Windows.UI.Xaml.Navigation;
using Windows.Web.Http;


namespace App6
{
public sealed partial class MainPage : Page
{
    public MainPage()
    {
        this.InitializeComponent();
    }

    private async void Sample()
    {
        Windows.Storage.Streams.IRandomAccessStream random = await Windows.Storage.Streams.RandomAccessStreamReference.CreateFromUri(new Uri("http://192.168.1.253/SnapShotJPEG?Resolution=320x240&Quality=Motion")).OpenReadAsync();

        Windows.Graphics.Imaging.BitmapDecoder decoder = await Windows.Graphics.Imaging.BitmapDecoder.CreateAsync(random);
        Windows.Graphics.Imaging.PixelDataProvider pixelData = await decoder.GetPixelDataAsync();

        byte[] bytes = pixelData.DetachPixelData();


        BitmapImage image = new BitmapImage();
        using (InMemoryRandomAccessStream stream = new InMemoryRandomAccessStream())
        {
            await stream.WriteAsync(bytes.AsBuffer());
            stream.Seek(0);
            await image.SetSourceAsync(stream);
        }
            IpCamera_1.Source = image; //IpCamera_1 is Image.

    }

    private void Hello_Click(object sender, RoutedEventArgs e)
    {
        Sample();
    }
}
}

有没有另一种解决方案，将视频从IP摄像头流式传输到Raspberry-Pi？我使用的是Windows-10-iot-core。

Answer 1

由于您要连接到本地网络，因此应向Package.appxmanifest添加一些所需的功能。在解决方案资源管理器中右键单击该文件，选择View code，然后在<Capabilities>元素中添加以下内容：

<Capabilities>
  <Capability Name="internetClient" />
  <Capability Name="internetClientServer" />
  <Capability Name="privateNetworkClientServer" />
</Capabilities>

Answer 2

请尝试将webcam功能添加到您的Package.appxmanifest。

  <Capabilities>
    <Capability Name="internetClient" />
    <Capability Name="privateNetworkClientServer" />
    <Capability Name="internetClientServer" />
    <DeviceCapability Name="webcam" />
  </Capabilities>

必须在Universal Windows Platform (UWP)应用程序的软件包清单中声明功能，才能访问某些API或资源(如图片、音乐或相机或麦克风等设备)。你可以参考App capability declarations。

网络摄像头功能提供对内置摄像头或外部摄像头的视频源的访问，从而允许应用程序捕获照片和视频。在Windows上，应用程序必须处理用户从设置符中禁用摄像头的情况。网络摄像头功能仅授予对视频流的访问权限。为了授予对音频流的访问权限，必须添加麦克风功能。