我正在使用MediaCapture
在屏幕上预览相机,这工作正常。
但是,我需要访问我的应用程序中的当前帧。因此,我添加FrameReader
到MediaCapture
获取事件 Reader_FrameArrived。
所以事件正在运行,但是位图本身始终为空。
我实现了 ecent 回调,就像示例中所示:
var mediaFrameReference = sender.TryAcquireLatestFrame();
var videoMediaFrame = mediaFrameReference?.VideoMediaFrame;
var softwareBitmap = videoMediaFrame?.SoftwareBitmap;
if (softwareBitmap != null)
{
Debug.WriteLine("here");
}
else
{
return;
}
这就是我初始化阅读器的方式:
var frameSourceGroups = await MediaFrameSourceGroup.FindAllAsync();
var allGroups = await MediaFrameSourceGroup.FindAllAsync();
var eligibleGroups = allGroups.Select(g => new
{
Group = g,
// For each source kind, find the source which offers that kind of media frame,
// or null if there is no such source.
SourceInfos = new MediaFrameSourceInfo[]
{
g.SourceInfos.FirstOrDefault(info => info.SourceKind == MediaFrameSourceKind.Color),
g.SourceInfos.FirstOrDefault(info => info.SourceKind == MediaFrameSourceKind.Depth),
g.SourceInfos.FirstOrDefault(info => info.SourceKind == MediaFrameSourceKind.Infrared),
}
}).Where(g => g.SourceInfos.Any(info => info != null)).ToList();
if (eligibleGroups.Count == 0)
{
System.Diagnostics.Debug.WriteLine("No source group with color, depth or infrared found.");
return;
}
var selectedGroupIndex = 0; // Select the first eligible group
MediaFrameSourceGroup selectedGroup = eligibleGroups[selectedGroupIndex].Group;
MediaFrameSourceInfo colorSourceInfo = eligibleGroups[selectedGroupIndex].SourceInfos[0];
MediaFrameSourceInfo infraredSourceInfo = eligibleGroups[selectedGroupIndex].SourceInfos[1];
MediaFrameSourceInfo depthSourceInfo = eligibleGroups[selectedGroupIndex].SourceInfos[2];
//_mediaCapture.FrameSources.TryGetValue(cameraDevice.Id, out _source);
var colorFrameSource = _mediaCapture.FrameSources[colorSourceInfo.Id];
if (colorFrameSource != null)
{
_reader = await _mediaCapture.CreateFrameReaderAsync(colorFrameSource, MediaEncodingSubtypes.Argb32);
_reader.FrameArrived += Reader_FrameArrived;
MediaFrameReaderStartStatus result = await _reader.StartAsync();
Debug.WriteLine(result.ToString());
}
任何想法为什么位图可能为空?