Question

我使用MediapCapture扫描QrCode。这是我的配置：

var cameras = await DeviceInformation.FindAllAsync(DeviceClass.VideoCapture);
int cameraIndex = cameras.Count > 1 ? 1 : 0;
MediaCaptureInitializationSettings settings = new MediaCaptureInitializationSettings { VideoDeviceId = cameras[cameraIndex].Id };
settings.StreamingCaptureMode = StreamingCaptureMode.Video;

await _mediaCapture.InitializeAsync();
SetResolution();
_mediaCapture.SetPreviewRotation(VideoRotation.Clockwise90Degrees);
_mediaCapture.VideoDeviceController.FocusControl.Configure(new Windows.Media.Devices.FocusSettings() { Mode = Windows.Media.Devices.FocusMode.Auto });
videoCapture.Source = _mediaCapture;
await _mediaCapture.StartPreviewAsync();

我的CaptureElement上还有一个Tapped事件，它调用了FocusAsync方法：

await _mediaCapture.VideoDeviceController.FocusControl.FocusAsync();

我的问题是，当我尝试聚焦时，我有时（并非总是）会出现错误（即使它是我第一次调用它时）。此错误是：

操作无效

修改

这是我的堆栈跟踪:(没有内部异常）

在System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务任务）在System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification（任务任务）在System.Runtime.CompilerServices.TaskAwaiter.GetResult（）在ProjectName.Views.QrCodeScannerPage.d__8.MoveNext（）

Answer 1

最后，我选择从以下示例中设置自动对焦： https://msdn.microsoft.com/en-us/windows/uwp/audio-video-camera/capture-device-controls-for-photo-and-video-capture

UWP MediaCapture FocusAsync：操作无效

1 个答案: