Windows phone 8.1 如何在windows phone 8.1上打开手电筒
我创建的项目基于: 我的问题是如何在WP8.1上启用闪光灯(手电筒) 我应该使用MediaCapture()吗 当我用它的时候,它就掉下来了Windows phone 8.1 如何在windows phone 8.1上打开手电筒,windows-phone-8.1,flashlight,Windows Phone 8.1,Flashlight,我创建的项目基于: 我的问题是如何在WP8.1上启用闪光灯(手电筒) 我应该使用MediaCapture()吗 当我用它的时候,它就掉下来了 var videoDev = mediaDev.VideoDeviceController; 通过未处理的异常 如何将手电筒添加到此示例项目中 您尚未初始化MediaCaptureSettings,因此当您尝试初始化videoController时,会发生异常。您需要初始化设置,让MediaCapture知道您要使用的设备,并设置VideoDevic
var videoDev = mediaDev.VideoDeviceController;
通过未处理的异常
- 如何将手电筒添加到此示例项目中李>
private async Task InitializeAndToggleTorch()
{
// Initialize Media Capture and Settings Objects, mediaCapture declared global outside this method
mediaCapture = new MediaCapture();
MediaCaptureInitializationSettings settings = new MediaCaptureInitializationSettings();
// Grab all available VideoCapture Devices and find rear device (usually has flash)
DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
DeviceInformation device = devices.FirstOrDefault(x => x.EnclosureLocation != null && x.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Back);
// Set Video Device to device with flash obtained from DeviceInformation
settings.VideoDeviceId = device.Id;
settings.AudioDeviceId = "";
settings.PhotoCaptureSource = PhotoCaptureSource.VideoPreview;
settings.StreamingCaptureMode = StreamingCaptureMode.Video;
mediaCapture.VideoDeviceController.PrimaryUse = Windows.Media.Devices.CaptureUse.Video;
// Initialize mediacapture now that settings are configured
await mediaCapture.InitializeAsync(settings);
if (mediaCapture.VideoDeviceController.TorchControl.Supported)
{
// Get resolutions and set to lowest available for temporary video file.
var resolutions = mediaCapture.VideoDeviceController.GetAvailableMediaStreamProperties(MediaStreamType.VideoRecord).Select(x => x as VideoEncodingProperties);
var lowestResolution = resolutions.OrderBy(x => x.Height * x.Width).ThenBy(x => (x.FrameRate.Numerator / (double)x.FrameRate.Denominator)).FirstOrDefault();
await mediaCapture.VideoDeviceController.SetMediaStreamPropertiesAsync(MediaStreamType.VideoRecord, lowestResolution);
// Get resolutions and set to lowest available for preview.
var previewResolutions = mediaCapture.VideoDeviceController.GetAvailableMediaStreamProperties (MediaStreamType.VideoPreview).Select(x => x as VideoEncodingProperties);
var lowestPreviewResolution = previewResolutions.OrderByDescending(x => x.Height * x.Width).ThenBy(x => (x.FrameRate.Numerator / (double)x.FrameRate.Denominator)).LastOrDefault();
await mediaCapture.VideoDeviceController.SetMediaStreamPropertiesAsync(MediaStreamType.VideoPreview, lowestPreviewResolution);
// Best practice, you should handle Media Capture Error events
mediaCapture.Failed += MediaCapture_Failed;
mediaCapture.RecordLimitationExceeded += MediaCapture_RecordLimitationExceeded;
}
else
{
// Torch not supported, exit method
return;
}
// Start Preview
var captureElement = new CaptureElement();
captureElement.Source = mediaCapture;
await mediaCapture.StartPreviewAsync();
// Prep for video recording
// Get Application temporary folder to store temporary video file folder
StorageFolder tempFolder = ApplicationData.Current.TemporaryFolder;
// Create a temp Flash folder
var folder = await tempFolder.CreateFolderAsync("TempFlashlightFolder", CreationCollisionOption.OpenIfExists);
// Create video encoding profile as MP4
var videoEncodingProperties = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Auto);
// Create new unique file in the Flash folder and record video
var videoStorageFile = await folder.CreateFileAsync("TempFlashlightFile", CreationCollisionOption.GenerateUniqueName);
// Start recording
await mediaCapture.StartRecordToStorageFileAsync(videoEncodingProperties, videoStorageFile);
// Now Toggle TorchControl property
mediaCapture.VideoDeviceController.TorchControl.Enabled = true;
}
呸!那有很多代码只是为了切换flash,对吧?好消息是,这在Windows 10中已通过新的Windows.Devices.Lights.Lamp API修复。您只需几行代码即可完成相同的工作:
请检查此线程以供参考:
例外情况是什么?你在什么设备上运行这个?您应该看看下面的CameraStarterKit示例。试着运行它,看看访问VideoDeviceController是否仍然会出现异常。我想指出,当USB电缆连接到PC时,即使在预览和录制时,火炬LED也会熄灭。我只是花了几个小时想弄清楚发生了什么。。。我的手机是Lumia 640 XL。
private async Task InitializeAndToggleTorch()
{
// Initialize Media Capture and Settings Objects, mediaCapture declared global outside this method
mediaCapture = new MediaCapture();
MediaCaptureInitializationSettings settings = new MediaCaptureInitializationSettings();
// Grab all available VideoCapture Devices and find rear device (usually has flash)
DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
DeviceInformation device = devices.FirstOrDefault(x => x.EnclosureLocation != null && x.EnclosureLocation.Panel == Windows.Devices.Enumeration.Panel.Back);
// Set Video Device to device with flash obtained from DeviceInformation
settings.VideoDeviceId = device.Id;
settings.AudioDeviceId = "";
settings.PhotoCaptureSource = PhotoCaptureSource.VideoPreview;
settings.StreamingCaptureMode = StreamingCaptureMode.Video;
mediaCapture.VideoDeviceController.PrimaryUse = Windows.Media.Devices.CaptureUse.Video;
// Initialize mediacapture now that settings are configured
await mediaCapture.InitializeAsync(settings);
if (mediaCapture.VideoDeviceController.TorchControl.Supported)
{
// Get resolutions and set to lowest available for temporary video file.
var resolutions = mediaCapture.VideoDeviceController.GetAvailableMediaStreamProperties(MediaStreamType.VideoRecord).Select(x => x as VideoEncodingProperties);
var lowestResolution = resolutions.OrderBy(x => x.Height * x.Width).ThenBy(x => (x.FrameRate.Numerator / (double)x.FrameRate.Denominator)).FirstOrDefault();
await mediaCapture.VideoDeviceController.SetMediaStreamPropertiesAsync(MediaStreamType.VideoRecord, lowestResolution);
// Get resolutions and set to lowest available for preview.
var previewResolutions = mediaCapture.VideoDeviceController.GetAvailableMediaStreamProperties (MediaStreamType.VideoPreview).Select(x => x as VideoEncodingProperties);
var lowestPreviewResolution = previewResolutions.OrderByDescending(x => x.Height * x.Width).ThenBy(x => (x.FrameRate.Numerator / (double)x.FrameRate.Denominator)).LastOrDefault();
await mediaCapture.VideoDeviceController.SetMediaStreamPropertiesAsync(MediaStreamType.VideoPreview, lowestPreviewResolution);
// Best practice, you should handle Media Capture Error events
mediaCapture.Failed += MediaCapture_Failed;
mediaCapture.RecordLimitationExceeded += MediaCapture_RecordLimitationExceeded;
}
else
{
// Torch not supported, exit method
return;
}
// Start Preview
var captureElement = new CaptureElement();
captureElement.Source = mediaCapture;
await mediaCapture.StartPreviewAsync();
// Prep for video recording
// Get Application temporary folder to store temporary video file folder
StorageFolder tempFolder = ApplicationData.Current.TemporaryFolder;
// Create a temp Flash folder
var folder = await tempFolder.CreateFolderAsync("TempFlashlightFolder", CreationCollisionOption.OpenIfExists);
// Create video encoding profile as MP4
var videoEncodingProperties = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Auto);
// Create new unique file in the Flash folder and record video
var videoStorageFile = await folder.CreateFileAsync("TempFlashlightFile", CreationCollisionOption.GenerateUniqueName);
// Start recording
await mediaCapture.StartRecordToStorageFileAsync(videoEncodingProperties, videoStorageFile);
// Now Toggle TorchControl property
mediaCapture.VideoDeviceController.TorchControl.Enabled = true;
}