swift - 错误=调用中传递了额外的尾随闭包，

Question

    //creates the session
    let session = AVCaptureSession()

    //Defines the capture device
   AVCaptureDevice.default(for: AVMediaType.video)
   {
      let input = AVCaptureDeviceInput(device: captureDevice)
      session.addInput(input)
    }

不确定如何解决此错误任何帮助将不胜感激

Answer 1

AVCaptureDevice.default 有一个返回值。您必须将其分配给一个变量。

因为这个值是可选的，所以安全地解开它

guard let captureDevice = AVCaptureDevice.default(for: AVMediaType.video),
      let input = try? AVCaptureDeviceInput(device: captureDevice) else { return }
session.addInput(input)