您可以从连接的设备下载日志(log)文件，也可以直接从应用程序发送.下面介绍这两种方法.

Send log files from app through email, in Swift

在引用DDFileLogger的类中编写此代码.我会把它放在一个定制的记录器类中，例如MyLogger.swift

var ddFileLogger: DDFileLogger!

var logFileDataArray: [NSData] {
    get {
        let logFilePaths = ddFileLogger.logFileManager.sortedLogFilePaths() as! [String]
        var logFileDataArray = [NSData]()
        for logFilePath in logFilePaths {
            let fileURL = NSURL(fileURLWithPath: logFilePath)
            if let logFileData = try? NSData(contentsOfURL: fileURL, options: NSDataReadingOptions.DataReadingMappedIfSafe) {
                // Insert at front to reverse the order, so that oldest logs appear first.
                logFileDataArray.insert(logFileData, atIndex: 0)
            }
        }
        return logFileDataArray
    }
}

然后，当用户点击一个按钮表示他们想要发送日志(log)时，

// Required by MFMailComposeViewController
import MessageUI

@IBAction func writeEmailTapped(sender: AnyObject) {
    if MFMailComposeViewController.canSendMail() {
        let composeVC = MFMailComposeViewController()
        composeVC.mailComposeDelegate = self

        // Configure the fields of the interface.
        composeVC.setToRecipients(["your-email@company.com"])
        composeVC.setSubject("Feedback for app")
        composeVC.setMessageBody("", isHTML: false)

        let attachmentData = NSMutableData()
        for logFileData in MyLogger.sharedInstance.logFileDataArray {
            attachmentData.appendData(logFileData)
        }
        composeVC.addAttachmentData(attachmentData, mimeType: "text/plain", fileName: "diagnostic.log")
        self.presentViewController(composeVC, animated: true, completion: nil)
    } else {
        // Tell user about not able to send email directly.
    }
}

这将导致出现一个" compose 邮箱"弹出窗口，其中包含一个名为diagnostic.log的附件文件，即所有连接在一起的日志(log)文件.

特别感谢——这是另一个答案给出的Objective-C版本的快速翻译.

Get log file(s) from device directly, through USB cable

如果您想获取应用程序在设备上运行时创建的日志(log)文件，

1. 将设备连接到mac电脑
2. In Xcode, go to Window -> Devices
3. 在设备列表的左上角，单击连接的设备.
4. 在主面板的"已安装的应用程序"部分中，单击运行CocoaLumberjack的应用程序.
5. 在已安装应用列表的底部，单击gear图标，然后下载容器.
6. 在Finder中，右键单击保存的屏幕上的(显示菜单).xcappdata文件，然后 Select "显示软件包内容"
7. 日志(log)文件保存在/AppData/Library/Caches/Logs/中

如果这对你有帮助的话，向上投票会很好！