Swift5.0 Alamofire download的一般使用

Alamofire download

1. 指定自己想要的文件名：
   就要重寫：DownloadRequest.DownloadFileDestination block
   具體代碼如下：

 let destination: DownloadRequest.DownloadFileDestination = {[weak self] (url, response) in
            let docmentURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first//文件路徑
            //response.suggestedFilename!:源文件名包括擴展eg：demo.xls
            let suggestFil = response.suggestedFilename == nil ? "http.xls" : response.suggestedFilename!
            //新文件名
            let newName = self!.fileName + "." + suggestFil.split(separator: ".").last!.description
            let fileRUL = docmentURL?.appendingPathComponent(newName)//拼接處完整的路徑
            return (fileRUL!, [.removePreviousFile,.createIntermediateDirectories])
        }

2. 僅僅指定文件目錄

let destination = DownloadRequest.suggestedDownloadDestination(for: .documentDirectory)

下載完整鏈接請求（包含下載進度）

fileprivate func reqestDownLoad() -> Void {
        
        Alamofire.download(urlTitle, to: destination).downloadProgress { progress in
            print("Download Progress: \(progress.fractionCompleted)")
            }.validate().responseData {[weak self] response in
//            response.result.value：響應數據Data
            if response.destinationURL != nil {
                //self!.filePath = response.destinationURL:目的地址可直接使用
            }
        }
    }