win8 metro 自己写摄像头拍照项目

这个项目不是用的系统自带的CameraCaptureUI。是自己写的摄像头的调用，界面做的不好所以，不放了。可是能够实现拍照功能：

以下是using 程序命名空间：

using Windows.Media.Capture;
using Windows.Media.MediaProperties;
using Windows.UI.Xaml.Media.Imaging;
using Windows.Storage;
using Windows.Storage.Pickers;
using Windows.Storage.Streams;
using Windows.Devices.Enumeration;

能够看看win8 引用中这些方法的调用情况，

以下是全局变量：

<span style="white-space:pre">	</span>private StorageFile file = null;
        private StorageFile photo = null;
        private StorageFile video = null;
        private MediaCapture mediaPhoto = null;
        private MediaCapture mediaVideo = null;
        private bool cameraStarted = false;

首先我们不调用系统自带的摄像头方法CameraCaptureUI，我们能够使用第二种方法，以下是调用摄像头的触发方法：

        private async void btnCamera_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
                if (devices.Count > 0)
                {
                    if (mediaPhoto == null)
                    {
                        mediaPhoto = new MediaCapture();
                        await mediaPhoto.InitializeAsync();
                        capture1.Source = mediaPhoto;
                        await mediaPhoto.StartPreviewAsync();
                        cameraStarted = true;
                    }
                }
            }
            catch (Exception msg)
            {
                mediaPhoto = null;
            }
        }

调用了摄像头，还要求实现拍照的功能：

<span style="white-space:pre">	</span>private async void btnPhoto_Click(object sender, RoutedEventArgs e)
        {
            if (mediaPhoto != null)
            {
                ImageEncodingProperties imgFormat = ImageEncodingProperties.CreateJpeg();
                photo = await ApplicationData.Current.LocalFolder.CreateFileAsync("hello.jpg", CreationCollisionOption.GenerateUniqueName);
                await mediaPhoto.CapturePhotoToStorageFileAsync(imgFormat, photo);
            }
        }

上面是拍照的触发方法。

我们程序还要求实现将拍好的照片保存好，这个还要求一个触发方法：

<span style="white-space:pre">	</span>private async void photoSave_Click(object sender, RoutedEventArgs e)
        {
            if (photo != null)
            {
                FileSavePicker photoPicker = new FileSavePicker();
                photoPicker.CommitButtonText = "保存图片";
                photoPicker.SuggestedFileName = "hello";
                photoPicker.FileTypeChoices.Add("图片",new string[]{".jpg",".jpeg",".png",".bmp"});
                photoPicker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
                StorageFile photoFile = await photoPicker.PickSaveFileAsync();
                if (photoFile != null)
                {
                    //打开通过摄像头拍摄的照片。并返回流，以流的形式读取文件
                    var streamRandom = await photo.OpenAsync(FileAccessMode.Read);
                    //将拍摄的照片以流的形式读取到缓冲区
                    IBuffer buffer = RandomAccessStreamToBuffer(streamRandom);
                    //将缓冲区内容写入对应的目录中
                    await FileIO.WriteBufferAsync(photoFile, buffer);
                }
            }
        }

以下是自己写的两个函数：

        //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);
                }
            }
            try
            {
                buffer = WindowsRuntimeBufferExtensions.GetWindowsRuntimeBuffer(memoryStream, 0, (int)memoryStream.Length);
            }
            catch (Exception msg)
            {
            }
            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();
            }
        }

能够执行，谢谢大家指正。