ios - 在完成 block AWS S3 Swift 3 中对成员异步执行的模糊引用

Question

在尝试使用 AWSTransferutility 通过 Swift 上传照片时，我收到此错误。对成员 async(execute:) 的模糊引用我搜索了类似的问题，但没有找到解决方案。

func uploadS3Background (dict: NSMutableDictionary) {

    let  transferUtility = AWSS3TransferUtility.default()
    let expression = AWSS3TransferUtilityUploadExpression()
    
    
    let completionHandler = { (task, error) -> Void in
        
        DispatchQueue.main.async(execute: {
            
        })
    }
    
    transferUtility.uploadFile(URL(fileURLWithPath: dict.object(forKey: "url") as! String),
    bucket: "bucketname/images",
    key: (dict.object(forKey: "filename") as! String),
    contentType: "image/png",
    expression: expression,
    completionHandler).continueWith { (task) -> AnyObject! in
        
        if let error = task.error
        {
            print("Error: \(error.localizedDescription)")
        }
            
        if let _ = task.result
        {
            // Do something with uploadTask.
        }
        
        return nil;
    }
}

在完成 block 之外，我没有收到在主队列上调度的错误。

Answer 1

在您的 View Controller 中声明这一点 -

var completionHandler: AWSS3TransferUtilityUploadCompletionHandlerBlock?

然后使用

self.completionHandler = { (task, error) -> Void in
            DispatchQueue.main.async(execute: {

      })
}