ios - 在 iOS 上拍摄照片时出现随机错误

Question

我在这里尝试捕捉图像:

var stillImageOutput = AVCaptureStillImageOutput()
stillImageOutput!.outputSettings = [AVVideoCodecKey: AVVideoCodecJPEG]

[...] 

if let videoConnection = stillImageOutput.connectionWithMediaType(AVMediaTypeVideo) {
     videoConnection.videoOrientation = AVCaptureVideoOrientation.Portrait
     println("enabled = \(videoConnection.enabled)") //enabled = true
     println("active = \(videoConnection.active)") //active = true
     stillImageOutput.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler: {
          (sampleBuffer, error) in
          if error != nil {
               println(error)
          }
     })
}

它在大多数时候都能完美运行!

但有时我在调用 captureStillImageAsynchronouslyFromConnection 时会出错:

Error Domain=AVFoundationErrorDomain Code=-11800 "The operation couldn't be completed." 
UserInfo=0x14682110 {NSLocalizedDescription=The operation couldn't be completed., 
NSUnderlyingError=0x1676be30 "The operation couldn't be completed.
(OSStatus error -16400.)", 
NSLocalizedFailureReason=An unknown error has occured (-16400)}

我只是想预料到这个错误会发生。我尝试测试 videoConnection.enabled 和 videoConnection.active 但两者似乎都与错误无关...

在拍摄照片之前我需要检查什么以确保一切正常？

Answer 1

我也收到了和你一样的错误信息。经过多次调试后，我意识到我在拍照前无意中停止了捕获 session 。仔细检查 AVCaptureSession 的 .running 属性是否为 true。