这是要求不适用CameraCaptureUI等使用系统自带的 camera UI界面，要求我们自己写调用摄像头摄像的方法，现在我把我的程序贴下：
UI界面的程序：
<Page
x:Class="Camera3.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Camera3"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Button x:Name="btnCamera" Content="调用摄像头" HorizontalAlignment="Left" Margin="295,83,0,0" VerticalAlignment="Top" Click="btnCamera_Click"/>
<Button x:Name="btnSettings" Content="摄像头设置" HorizontalAlignment="Left" Margin="482,83,0,0" VerticalAlignment="Top"/>
<Button x:Name="btnVideo" Content="拍摄视频" HorizontalAlignment="Left" Margin="685,83,0,0" VerticalAlignment="Top" Click="btnVideo_Click"/>
<Button x:Name="btnSave" Content="保存视频" HorizontalAlignment="Left" Margin="867,83,0,0" VerticalAlignment="Top" Click="btnSave_Click"/>
<GridView HorizontalAlignment="Left" Margin="246,200,0,0" VerticalAlignment="Top" Width="800" Height="600">
<CaptureElement x:Name="capture1" Height="600" Width="800"/>
</GridView>
</Grid>
</Page>
主程序里的代码：
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
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 Windows.Media.Capture;
using Windows.Storage;
using Windows.Storage.Pickers;
using Windows.Devices.Enumeration;
using Windows.Media.MediaProperties;
using Windows.UI.Xaml.Media.Imaging;
using Windows.UI.Xaml.Media;
using Windows.Storage.Streams;
using Windows.Media.Devices;
using System.Threading.Tasks;
// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238
namespace Camera3
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
private MediaCapture mediaVideo = null;
private IStorageFile video = null;
private MediaEncodingProfile videoProfile = null;
public MainPage()
{
this.InitializeComponent();
}
public async void btnCamera_Click(object sender, RoutedEventArgs e)
{
try
{
DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
if (devices.Count > 0)
{
if (mediaVideo == null)
{
capture1.Source = await Initialize();
await mediaVideo.StartPreviewAsync();
}
}
}
catch (Exception msg)
{
mediaVideo = null;
}
}
public async Task<MediaCapture> Initialize()
{
mediaVideo = new MediaCapture();
await mediaVideo.InitializeAsync();
mediaVideo.VideoDeviceController.PrimaryUse = CaptureUse.Video;
videoProfile = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Auto);
return mediaVideo;
}
public async void btnVideo_Click(object sender, RoutedEventArgs e)
{
if (mediaVideo != null)
{
video = await KnownFolders.VideosLibrary.CreateFileAsync("some.mp4", CreationCollisionOption.GenerateUniqueName);
await mediaVideo.StartRecordToStorageFileAsync(videoProfile, video);
}
}
private async void btnSave_Click(object sender, RoutedEventArgs e)
{
if (video != null)
{
FileSavePicker videoPicker = new FileSavePicker();
videoPicker.CommitButtonText = "保存视频";
videoPicker.SuggestedFileName = "hello";
videoPicker.FileTypeChoices.Add("视频", new string[] { ".mp4", ".mpg", ".rmvb", ".mkv" });
videoPicker.SuggestedStartLocation = PickerLocationId.VideosLibrary;
IStorageFile videoFile = await videoPicker.PickSaveFileAsync();
if (videoFile != null)
{
var streamRandom = await video.OpenAsync(FileAccessMode.Read);
IBuffer buffer = RandomAccessStreamToBuffer(streamRandom);
await FileIO.WriteBufferAsync(videoFile, buffer);
}
}
}
//将图片写入到缓冲区
private IBuffer RandomAccessStreamToBuffer(IRandomAccessStream randomstream)
{
Stream stream = WindowsRuntimeStreamExtensions.AsStreamForRead(randomstream.GetInputStreamAt(0));
MemoryStream memoryStream = new MemoryStream();
IBuffer buffer = null;
if (stream != null)
{
byte[] bytes = ConvertStreamTobyte(stream); //将流转化为字节型数组
if (bytes != null)
{
var binaryWriter = new BinaryWriter(memoryStream);
binaryWriter.Write(bytes);
}
}
buffer = WindowsRuntimeBufferExtensions.GetWindowsRuntimeBuffer(memoryStream, 0, (int)memoryStream.Length);
return buffer;
}
//将流转换成二进制
public static byte[] ConvertStreamTobyte(Stream input)
{
byte[] buffer = new byte[1024 * 1024];
using (MemoryStream ms = new MemoryStream())
{
int read;
while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
{
ms.Write(buffer, 0, read);
}
return ms.ToArray();
}
}
}
}
但是这里出现了一个问题，不知道怎么解决。
之所以放上来，希望有大牛可以帮我解决一下，看看到底是出现了什么问题：
这是运行的界面，点击“调用摄像头”，可以调用摄像头：
会发现上面的界面已经调用了摄像头，这一个模块式没有什么问题的。
但是问题出现在下面，下面我点击“拍摄视频”的按钮，出现如下异常：
下面我把我捕获的异常给大家看看：
System.Exception: The specified object or value does not exist.
MediaStreamType
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
at Camera3.MainPage.<btnVideo_Click>d__9.MoveNext()
上面就是捕获的异常情况，可以从异常的截图上发现，出现异常的代码可能是：
public async void btnVideo_Click(object sender, RoutedEventArgs e)
{
if (mediaVideo != null)
{
video = await KnownFolders.VideosLibrary.CreateFileAsync("some.mp4", CreationCollisionOption.GenerateUniqueName);
<span style="color:#ff0000;">await mediaVideo.StartRecordToStorageFileAsync(videoProfile, video);</span>
}
}
应该就是标记为红色的那部分代码，下面我对它进行断点调试：
上面两幅断点调试的图片可以看出这
<span style="color:#ff0000;">StartRecordToStorageFileAsync(videoProfile, video)</span>
这个函数的两个参数均没有出现问题，参数的传递的正确的，现在怎么会出现这样的情况。
希望知道的同学可以给我答案，告诉我为什么，等待您的回复，谢谢同志们。
PS：搞了一下午，终于发现了这个程序的问题，现在把正确的程序源代码传上去。
下面是我的程序源代码，希望打啊多多指正。
http://download.csdn.net/detail/litianpeng1991/7556273