Question

长话短说，我实现了AVCaptureFileOutputRecordingDelegate，但XCode并没有认识到所需的方法。

自从我开始将代码迁移到Swift 3后，实现此委托的类继续发出错误

Type 'VideoViewController' does not conform to protocol 'AVCaptureFileOutputRecordingDelegate'

我知道我只需要实现这个方法

public func capture(_ captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAt outputFileURL: URL!, fromConnections connections: [Any]!, error: Error!)

所以，到目前为止我做了什么：

清理项目（没有工作）
清理了构建文件夹（没有工作）
创建了一个实现此委托的新项目（此工作）
评论了所有其他不属于此代表的功能（没有工作）
在我的项目中创建了一个新的ViewController，它只实现了这个委托（没有工作）
关闭XCode以确保没有缓存问题（没有工作= /）
尝试在旧版本的XCode中运行项目

有时候XCode建议修复它来实现＆＃34;缺失＆＃34;方法

    /*!
 @method captureOutput:didFinishRecordingToOutputFileAtURL:fromConnections:error:
 @abstract
 Informs the delegate when all pending data has been written to an output file.

 @param captureOutput
 The capture file output that has finished writing the file.
 @param fileURL
 The file URL of the file that has been written.
 @param connections
 An array of AVCaptureConnection objects attached to the file output that provided the data that was written to the file.
 @param error
 An error describing what caused the file to stop recording, or nil if there was no error.

 @discussion
 This method is called when the file output has finished writing all data to a file whose recording was stopped, either because startRecordingToOutputFileURL:recordingDelegate: or stopRecording were called, or because an error, described by the error parameter, occurred (if no error occurred, the error parameter will be nil). This method will always be called for each recording request, even if no data is successfully written to the file.

 Clients should not assume that this method will be called on a specific thread.

 Delegates are required to implement this method.
 */
@available(iOS 4.0, *)
public func capture(_ captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAt outputFileURL: URL!, fromConnections connections: [Any]!, error: Error!) {

}

但在此之后，XCode说该方法是重复的，并且仍然说该类没有实现所需的方法

任何人都知道为什么会这样，以及如何解决它？

谢谢大家

编辑1

这是我在我的项目中创建的类，用于测试并发生相同的错误

import Foundation
import AVFoundation

class VVC : UIViewController, AVCaptureFileOutputRecordingDelegate {
/*!
 @method captureOutput:didFinishRecordingToOutputFileAtURL:fromConnections:error:
 @abstract
 Informs the delegate when all pending data has been written to an output file.

 @param captureOutput
 The capture file output that has finished writing the file.
 @param fileURL
 The file URL of the file that has been written.
 @param connections
 An array of AVCaptureConnection objects attached to the file output that provided the data that was written to the file.
 @param error
 An error describing what caused the file to stop recording, or nil if there was no error.

 @discussion
 This method is called when the file output has finished writing all data to a file whose recording was stopped, either because startRecordingToOutputFileURL:recordingDelegate: or stopRecording were called, or because an error, described by the error parameter, occurred (if no error occurred, the error parameter will be nil). This method will always be called for each recording request, even if no data is successfully written to the file.

 Clients should not assume that this method will be called on a specific thread.

 Delegates are required to implement this method.
 */
@available(iOS 4.0, *)
func capture(_ captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAt outputFileURL: URL!, fromConnections connections: [Any]!, error: Error!) {

}
}

Answer 1

不确定这是否是您的问题的原因，但我遇到了同样的问题，这是由于 Candidate has non matching type 错误造成的。

我创建了一个名为 Error 的新类型，它的完整命名空间名称为 [Namespace].Error，这与 Swift 的 Error 类型相冲突。

在实现 AVCaptureFileOutputRecordingDelegate 时 XCode 将添加协议函数签名并且 didFinishRecordingTo 函数具有 Error 类型。我不得不将其更改为 Swift.Error

类型的 Swift 版本

func fileOutput(
    _ output: AVCaptureFileOutput,
    didFinishRecordingTo outputFileURL: URL,
    from connections: [AVCaptureConnection],
    error: Swift.Error?
) {
    ...
}

AVCaptureFileOutputRecordingDelegate无法识别实现的方法Swift 3

1 个答案: