Question

我在C＃和VS2013中为Lumia 640 XL WP 8.1编写了一个简单的代码，就像一个示例照片应用程序。还不错，但它有一点问题：当图片保存到媒体时，这张图片会向左旋转90度。

以下是我设置预览区域的代码：

captureManager = new MediaCapture();
await captureManager.InitializeAsync();
captureManager.SetPreviewRotation(VideoRotation.Clockwise90Degrees);
captureManager.SetRecordRotation(VideoRotation.Clockwise90Degrees);
cptElement.Source = captureManager;
await captureManager.StartPreviewAsync();

以下是捕获代码：

ImageEncodingProperties imgFormat = ImageEncodingProperties.CreateJpeg();
StorageFile file = await KnownFolders.PicturesLibrary.CreateFileAsync("Photo.jpg", CreationCollisionOption.GenerateUniqueName);
await captureManager.CapturePhotoToStorageFileAsync(imgFormat, file);

所以，您可能会看到，我试图在此命令行中旋转最终图片：

captureManager.SetRecordRotation(VideoRotation.Clockwise90Degrees);

但它没有奏效。

在这种情况下我该怎么办？

感谢您的帮助，对不起我的纯英语。

Answer 1

你应该看CameraStarterKit SDK sample。它将向您展示如何旋转：

预览：

/// <summary>
/// Gets the current orientation of the UI in relation to the device (when AutoRotationPreferences cannot be honored) and applies a corrective rotation to the preview
/// </summary>
private async Task SetPreviewRotationAsync()
{
    // Only need to update the orientation if the camera is mounted on the device
    if (_externalCamera) return;

    // Calculate which way and how far to rotate the preview
    int rotationDegrees = ConvertDisplayOrientationToDegrees(_displayOrientation);

    // The rotation direction needs to be inverted if the preview is being mirrored
    if (_mirroringPreview)
    {
        rotationDegrees = (360 - rotationDegrees) % 360;
    }

    // Add rotation metadata to the preview stream to make sure the aspect ratio / dimensions match when rendering and getting preview frames
    var props = _mediaCapture.VideoDeviceController.GetMediaStreamProperties(MediaStreamType.VideoPreview);
    props.Properties.Add(RotationKey, rotationDegrees);
    await _mediaCapture.SetEncodingPropertiesAsync(MediaStreamType.VideoPreview, props, null);
}

照片：

/// <summary>
/// Takes a photo to a StorageFile and adds rotation metadata to it
/// </summary>
/// <returns></returns>
private async Task TakePhotoAsync()
{
    // While taking a photo, keep the video button enabled only if the camera supports simultaneously taking pictures and recording video
    VideoButton.IsEnabled = _mediaCapture.MediaCaptureSettings.ConcurrentRecordAndPhotoSupported;

    // Make the button invisible if it's disabled, so it's obvious it cannot be interacted with
    VideoButton.Opacity = VideoButton.IsEnabled ? 1 : 0;

    var stream = new InMemoryRandomAccessStream();

    try
    {
        Debug.WriteLine("Taking photo...");
        await _mediaCapture.CapturePhotoToStreamAsync(ImageEncodingProperties.CreateJpeg(), stream);
        Debug.WriteLine("Photo taken!");

        var photoOrientation = ConvertOrientationToPhotoOrientation(GetCameraOrientation());

        await ReencodeAndSavePhotoAsync(stream, photoOrientation);
    }
    catch (Exception ex)
    {
        // File I/O errors are reported as exceptions
        Debug.WriteLine("Exception when taking a photo: {0}", ex.ToString());
    }
}

视频：

/// <summary>
/// Records an MP4 video to a StorageFile and adds rotation metadata to it
/// </summary>
/// <returns></returns>
private async Task StartRecordingAsync()
{
    try
    {
        // Create storage file in Pictures Library
        var videoFile = await KnownFolders.PicturesLibrary.CreateFileAsync("SimpleVideo.mp4", CreationCollisionOption.GenerateUniqueName);

        var encodingProfile = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Auto);

        // Calculate rotation angle, taking mirroring into account if necessary
        var rotationAngle = 360 - ConvertDeviceOrientationToDegrees(GetCameraOrientation());
        encodingProfile.Video.Properties.Add(RotationKey, PropertyValue.CreateInt32(rotationAngle));

        Debug.WriteLine("Starting recording...");

        await _mediaCapture.StartRecordToStorageFileAsync(encodingProfile, videoFile);
        _isRecording = true;

        Debug.WriteLine("Started recording!");
    }
    catch (Exception ex)
    {
        // File I/O errors are reported as exceptions
        Debug.WriteLine("Exception when starting video recording: {0}", ex.ToString());
    }
}

但是你应该查看完整的样本以查看方向/旋转信息的来源，并获得辅助函数。

如何在WP8.1中旋转captureManager保存的照片

1 个答案: