这个问题是由 currentRequest 和 originalRequest NSKeyArchived 编码的一个不寻常的根“NSKeyedArchiveRootObjectKey”而不是 NSKeyedArchiveRootObjectKey 常量（字面意思是“根”）和 NSURL(Mutable)Request 的编码过程中的一些其他不当行为引起的。
我在 beta 1 中检测到了这一点并提交了一个错误（编号 27144153，以防您想要复制）。甚至我也向 NSURLSession 团队的支持人员“Quinn the Eskimo”（apple dot com 的爱斯基摩人）发送了一封电子邮件，以确认他们收到了它，他说他们收到了并且知道问题。
更新：我终于想出了如何解决这个问题。将数据提供给correctResumeData() 函数，它将返回可用的简历数据
更新 2：您可以使用 NSURLSession.correctedDownloadTaskWithResumeData() / URLSession.correctedDownloadTask(withResumeData:) 函数来获取具有正确 originalRequest 和 currentRequest 变量的任务
更新 3： Quinn 说此问题已在 iOS 10.2 中解决，您可以继续使用此代码与 iOS 10.0 和 10.1 兼容，并且它可以在新版本中正常工作。 p>
（对于 Swift 3 代码，请向下滚动，对于 Objective C，请参阅 leavesstar post，但我没有对其进行测试）
Swift 2.3：
func correctRequestData(data: NSData?) -> NSData? {
guard let data = data else {
return nil
}
// return the same data if it's correct
if NSKeyedUnarchiver.unarchiveObjectWithData(data) != nil {
return data
}
guard let archive = (try? NSPropertyListSerialization.propertyListWithData(data, options: [.MutableContainersAndLeaves], format: nil)) as? NSMutableDictionary else {
return nil
}
// Rectify weird __nsurlrequest_proto_props objects to $number pattern
var k = 0
while archive["$objects"]?[1].objectForKey("$\(k)") != nil {
k += 1
}
var i = 0
while archive["$objects"]?[1].objectForKey("__nsurlrequest_proto_prop_obj_\(i)") != nil {
let arr = archive["$objects"] as? NSMutableArray
if let dic = arr?[1] as? NSMutableDictionary, let obj = dic["__nsurlrequest_proto_prop_obj_\(i)"] {
dic.setObject(obj, forKey: "$\(i + k)")
dic.removeObjectForKey("__nsurlrequest_proto_prop_obj_\(i)")
arr?[1] = dic
archive["$objects"] = arr
}
i += 1
}
if archive["$objects"]?[1].objectForKey("__nsurlrequest_proto_props") != nil {
let arr = archive["$objects"] as? NSMutableArray
if let dic = arr?[1] as? NSMutableDictionary, let obj = dic["__nsurlrequest_proto_props"] {
dic.setObject(obj, forKey: "$\(i + k)")
dic.removeObjectForKey("__nsurlrequest_proto_props")
arr?[1] = dic
archive["$objects"] = arr
}
}
// Rectify weird "NSKeyedArchiveRootObjectKey" top key to NSKeyedArchiveRootObjectKey = "root"
if archive["$top"]?.objectForKey("NSKeyedArchiveRootObjectKey") != nil {
archive["$top"]?.setObject(archive["$top"]?["NSKeyedArchiveRootObjectKey"], forKey: NSKeyedArchiveRootObjectKey)
archive["$top"]?.removeObjectForKey("NSKeyedArchiveRootObjectKey")
}
// Reencode archived object
let result = try? NSPropertyListSerialization.dataWithPropertyList(archive, format: NSPropertyListFormat.BinaryFormat_v1_0, options: NSPropertyListWriteOptions())
return result
}
func getResumeDictionary(data: NSData) -> NSMutableDictionary? {
var iresumeDictionary: NSMutableDictionary? = nil
// In beta versions, resumeData is NSKeyedArchive encoded instead of plist
if #available(iOS 10.0, OSX 10.12, *) {
var root : AnyObject? = nil
let keyedUnarchiver = NSKeyedUnarchiver(forReadingWithData: data)
do {
root = try keyedUnarchiver.decodeTopLevelObjectForKey("NSKeyedArchiveRootObjectKey") ?? nil
if root == nil {
root = try keyedUnarchiver.decodeTopLevelObjectForKey(NSKeyedArchiveRootObjectKey)
}
} catch {}
keyedUnarchiver.finishDecoding()
iresumeDictionary = root as? NSMutableDictionary
}
if iresumeDictionary == nil {
do {
iresumeDictionary = try NSPropertyListSerialization.propertyListWithData(data, options: [.MutableContainersAndLeaves], format: nil) as? NSMutableDictionary;
} catch {}
}
return iresumeDictionary
}
func correctResumeData(data: NSData?) -> NSData? {
let kResumeCurrentRequest = "NSURLSessionResumeCurrentRequest"
let kResumeOriginalRequest = "NSURLSessionResumeOriginalRequest"
guard let data = data, let resumeDictionary = getResumeDictionary(data) else {
return nil
}
resumeDictionary[kResumeCurrentRequest] = correctRequestData(resumeDictionary[kResumeCurrentRequest] as? NSData)
resumeDictionary[kResumeOriginalRequest] = correctRequestData(resumeDictionary[kResumeOriginalRequest] as? NSData)
let result = try? NSPropertyListSerialization.dataWithPropertyList(resumeDictionary, format: NSPropertyListFormat.XMLFormat_v1_0, options: NSPropertyListWriteOptions())
return result
}
extension NSURLSession {
func correctedDownloadTaskWithResumeData(resumeData: NSData) -> NSURLSessionDownloadTask {
let kResumeCurrentRequest = "NSURLSessionResumeCurrentRequest"
let kResumeOriginalRequest = "NSURLSessionResumeOriginalRequest"
let cData = correctResumeData(resumeData) ?? resumeData
let task = self.downloadTaskWithResumeData(cData)
// a compensation for inability to set task requests in CFNetwork.
// While you still get -[NSKeyedUnarchiver initForReadingWithData:]: data is NULL error,
// this section will set them to real objects
if let resumeDic = getResumeDictionary(cData) {
if task.originalRequest == nil, let originalReqData = resumeDic[kResumeOriginalRequest] as? NSData, let originalRequest = NSKeyedUnarchiver.unarchiveObjectWithData(originalReqData) as? NSURLRequest {
task.setValue(originalRequest, forKey: "originalRequest")
}
if task.currentRequest == nil, let currentReqData = resumeDic[kResumeCurrentRequest] as? NSData, let currentRequest = NSKeyedUnarchiver.unarchiveObjectWithData(currentReqData) as? NSURLRequest {
task.setValue(currentRequest, forKey: "currentRequest")
}
}
return task
}
}
斯威夫特 3：
func correct(requestData data: Data?) -> Data? {
guard let data = data else {
return nil
}
if NSKeyedUnarchiver.unarchiveObject(with: data) != nil {
return data
}
guard let archive = (try? PropertyListSerialization.propertyList(from: data, options: [.mutableContainersAndLeaves], format: nil)) as? NSMutableDictionary else {
return nil
}
// Rectify weird __nsurlrequest_proto_props objects to $number pattern
var k = 0
while ((archive["$objects"] as? NSArray)?[1] as? NSDictionary)?.object(forKey: "$\(k)") != nil {
k += 1
}
var i = 0
while ((archive["$objects"] as? NSArray)?[1] as? NSDictionary)?.object(forKey: "__nsurlrequest_proto_prop_obj_\(i)") != nil {
let arr = archive["$objects"] as? NSMutableArray
if let dic = arr?[1] as? NSMutableDictionary, let obj = dic["__nsurlrequest_proto_prop_obj_\(i)"] {
dic.setObject(obj, forKey: "$\(i + k)" as NSString)
dic.removeObject(forKey: "__nsurlrequest_proto_prop_obj_\(i)")
arr?[1] = dic
archive["$objects"] = arr
}
i += 1
}
if ((archive["$objects"] as? NSArray)?[1] as? NSDictionary)?.object(forKey: "__nsurlrequest_proto_props") != nil {
let arr = archive["$objects"] as? NSMutableArray
if let dic = arr?[1] as? NSMutableDictionary, let obj = dic["__nsurlrequest_proto_props"] {
dic.setObject(obj, forKey: "$\(i + k)" as NSString)
dic.removeObject(forKey: "__nsurlrequest_proto_props")
arr?[1] = dic
archive["$objects"] = arr
}
}
/* I think we have no reason to keep this section in effect
for item in (archive["$objects"] as? NSMutableArray) ?? [] {
if let cls = item as? NSMutableDictionary, cls["$classname"] as? NSString == "NSURLRequest" {
cls["$classname"] = NSString(string: "NSMutableURLRequest")
(cls["$classes"] as? NSMutableArray)?.insert(NSString(string: "NSMutableURLRequest"), at: 0)
}
}*/
// Rectify weird "NSKeyedArchiveRootObjectKey" top key to NSKeyedArchiveRootObjectKey = "root"
if let obj = (archive["$top"] as? NSMutableDictionary)?.object(forKey: "NSKeyedArchiveRootObjectKey") as AnyObject? {
(archive["$top"] as? NSMutableDictionary)?.setObject(obj, forKey: NSKeyedArchiveRootObjectKey as NSString)
(archive["$top"] as? NSMutableDictionary)?.removeObject(forKey: "NSKeyedArchiveRootObjectKey")
}
// Reencode archived object
let result = try? PropertyListSerialization.data(fromPropertyList: archive, format: PropertyListSerialization.PropertyListFormat.binary, options: PropertyListSerialization.WriteOptions())
return result
}
func getResumeDictionary(_ data: Data) -> NSMutableDictionary? {
// In beta versions, resumeData is NSKeyedArchive encoded instead of plist
var iresumeDictionary: NSMutableDictionary? = nil
if #available(iOS 10.0, OSX 10.12, *) {
var root : AnyObject? = nil
let keyedUnarchiver = NSKeyedUnarchiver(forReadingWith: data)
do {
root = try keyedUnarchiver.decodeTopLevelObject(forKey: "NSKeyedArchiveRootObjectKey") ?? nil
if root == nil {
root = try keyedUnarchiver.decodeTopLevelObject(forKey: NSKeyedArchiveRootObjectKey)
}
} catch {}
keyedUnarchiver.finishDecoding()
iresumeDictionary = root as? NSMutableDictionary
}
if iresumeDictionary == nil {
do {
iresumeDictionary = try PropertyListSerialization.propertyList(from: data, options: PropertyListSerialization.ReadOptions(), format: nil) as? NSMutableDictionary;
} catch {}
}
return iresumeDictionary
}
func correctResumeData(_ data: Data?) -> Data? {
let kResumeCurrentRequest = "NSURLSessionResumeCurrentRequest"
let kResumeOriginalRequest = "NSURLSessionResumeOriginalRequest"
guard let data = data, let resumeDictionary = getResumeDictionary(data) else {
return nil
}
resumeDictionary[kResumeCurrentRequest] = correct(requestData: resumeDictionary[kResumeCurrentRequest] as? Data)
resumeDictionary[kResumeOriginalRequest] = correct(requestData: resumeDictionary[kResumeOriginalRequest] as? Data)
let result = try? PropertyListSerialization.data(fromPropertyList: resumeDictionary, format: PropertyListSerialization.PropertyListFormat.xml, options: PropertyListSerialization.WriteOptions())
return result
}
extension URLSession {
func correctedDownloadTask(withResumeData resumeData: Data) -> URLSessionDownloadTask {
let kResumeCurrentRequest = "NSURLSessionResumeCurrentRequest"
let kResumeOriginalRequest = "NSURLSessionResumeOriginalRequest"
let cData = correctResumeData(resumeData) ?? resumeData
let task = self.downloadTask(withResumeData: cData)
// a compensation for inability to set task requests in CFNetwork.
// While you still get -[NSKeyedUnarchiver initForReadingWithData:]: data is NULL error,
// this section will set them to real objects
if let resumeDic = getResumeDictionary(cData) {
if task.originalRequest == nil, let originalReqData = resumeDic[kResumeOriginalRequest] as? Data, let originalRequest = NSKeyedUnarchiver.unarchiveObject(with: originalReqData) as? NSURLRequest {
task.setValue(originalRequest, forKey: "originalRequest")
}
if task.currentRequest == nil, let currentReqData = resumeDic[kResumeCurrentRequest] as? Data, let currentRequest = NSKeyedUnarchiver.unarchiveObject(with: currentReqData) as? NSURLRequest {
task.setValue(currentRequest, forKey: "currentRequest")
}
}
return task
}
}