Swift 3:传输实用程序enumerateToAssignBlocks方法签名

Question

正式的AWS文档包含以下目标-c代码

 AWSS3TransferUtility *transferUtility = [AWSS3TransferUtility defaultS3TransferUtility];
[transferUtility
 enumerateToAssignBlocksForUploadTask:^(AWSS3TransferUtilityUploadTask *uploadTask, __autoreleasing AWSS3TransferUtilityUploadProgressBlock *uploadProgressBlockReference, __autoreleasing AWSS3TransferUtilityUploadCompletionHandlerBlock *completionHandlerReference) {
     NSLog(@"%lu", (unsigned long)uploadTask.taskIdentifier);

     // Use `uploadTask.taskIdentifier` to determine what blocks to assign.

     *uploadProgressBlockReference = // Reassign your progress feedback block.
     *completionHandlerReference = // Reassign your completion handler.
 }
 downloadTask:^(AWSS3TransferUtilityDownloadTask *downloadTask, __autoreleasing AWSS3TransferUtilityDownloadProgressBlock *downloadProgressBlockReference, __autoreleasing AWSS3TransferUtilityDownloadCompletionHandlerBlock *completionHandlerReference) {
     NSLog(@"%lu", (unsigned long)downloadTask.taskIdentifier);

     // Use `downloadTask.taskIdentifier` to determine what blocks to assign.

     *downloadProgressBlockReference =  // Reassign your progress feedback block.
     *completionHandlerReference = // Reassign your completion handler.
 }];

我试着把它转换成Swift 3(仅上传任务)

transferUtility.enumerateToAssignBlocks(forUploadTask:
        {

            let progressPointer = AutoreleasingUnsafeMutablePointer<AWSS3TransferUtilityUploadProgressBlock?>(&uploadProgressBlock)
            let completionPointer = AutoreleasingUnsafeMutablePointer<AWSS3TransferUtilityUploadCompletionHandlerBlock?>(&completionBlock)

            progress = progressPointer
            completion = completionPointer

    }
        , downloadTask: nil)

但是Xcode引发以下错误

无法将类型()->()的值转换为预期的参数类型.

有人让它在Swift 3里工作吗？方法签名可能已经更改。

编辑：

我申请了@donkon的回答：

        transferUtility.enumerateToAssignBlocks(forUploadTask: { (uploadTask:AWSS3TransferUtilityUploadTask, progress:AutoreleasingUnsafeMutablePointer<(@convention(block) (AWSS3TransferUtilityTask, Progress) -> Void)?>?, error: AutoreleasingUnsafeMutablePointer<(@convention(block) (AWSS3TransferUtilityUploadTask, Error?) -> Void)?>?) in

                        let progressPointer = AutoreleasingUnsafeMutablePointer<AWSS3TransferUtilityProgressBlock?>(&self.progressBlock)
                        let completionPointer = AutoreleasingUnsafeMutablePointer<AWSS3TransferUtilityUploadCompletionHandlerBlock?>(&self.completionHandler)
        //

                        progress = progressPointer

                        completion = completionPointer


    }, downloadTask: nil)

现在，Xcode告诉我们，进度和完成都是let值，不能更改。

Answer 1

您尝试使用的方法具有函数参数。SDK中的这些函数是在Objective中编写的。因此，您应该使用@convention(block)来表明它们是与Objective兼容的块引用。

AWSS3TransferUtility.default().enumerateToAssignBlocks(forUploadTask: { (uploadTask:AWSS3TransferUtilityUploadTask, uploadProgressBlockReference:AutoreleasingUnsafeMutablePointer<(@convention(block) (AWSS3TransferUtilityTask, Progress) -> Void)?>?, completionHandlerReference: AutoreleasingUnsafeMutablePointer<(@convention(block) (AWSS3TransferUtilityUploadTask, Error?) -> Void)?>?) in
    print("Hello, world")

    uploadProgressBlockReference?.pointee = {(task:AWSS3TransferUtilityTask, progress:Progress) -> Void in
        print("Fraction completed:  \(progress.fractionCompleted)")
    }
}, downloadTask: nil)

Answer 2

不值得迅速地与那种方法作斗争，只要绕过它就行了。我敢肯定这件事也是这么做的。

 func handleForeground() {
    if let multiPartUploadTasks = self.transferUtility.getMultiPartUploadTasks().result, let uploads = multiPartUploadTasks as? [AWSS3TransferUtilityMultiPartUploadTask] {
        for upload in uploads {
            upload.setProgressBlock(self.progressBlock)
            upload.setCompletionHandler(self.completionBlock)
        }
    }
}