来自 CNContactStore requestAccess 的错误 "A promise was finished incorrectly"
Error "A promise was finished incorrectly" from CNContactStore requestAccess
我正在构建一个 UI 以请求访问 CNContactStore 并处理用户先前（并且可能错误地）拒绝访问的情况。当我检测到当前状态为 .denied 时，我会显示一个 UIAlertController，解释并提议将它们带到应用程序设置以允许访问。
在当前状态为 .denied 的情况下调用 store.requestAccess() 时，应用程序崩溃并显示两个错误：1) "A promise was finished with a nil error." 和 2) "A promise was finished incorrectly."。调用堆栈如下所示。
我不擅长解释调用堆栈，但我认为错误来自 CNContactStore 内部。我不清楚我能做些什么来防止这个错误。
编辑：我根本没有在我的应用程序中使用承诺链。
EDIT2：上面明确说明了我的代码中发生错误的确切位置。
import UIKit
import Contacts
import ContactsUI
final class ContactsAppHelper {
static let shared = ContactsAppHelper()
var store = CNContactStore()
func checkAccessStatus(_ completionHandler: @escaping (_ accessGranted: Bool) -> Void) {
let authorizationStatus = CNContactStore.authorizationStatus(for: .contacts)
switch authorizationStatus {
case .authorized:
completionHandler(true)
case .denied, .notDetermined:
store.requestAccess(for: .contacts, completionHandler: { (access, accessError) -> Void in
if access {
completionHandler(access)
}
else {
print("access denied")
DispatchQueue.main.sync {
self.showSettingsAlert(completionHandler)
}
}
})
default:
completionHandler(false)
}
}
private func showSettingsAlert(_ completionHandler: @escaping (_ accessGranted: Bool) -> Void) {
let msg = "This app requires access to Contacts to proceed. Would you like to open settings and grant permission?"
let alert = UIAlertController(title: nil, message: msg, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Open Settings", style: .default) { action in
completionHandler(false)
UIApplication.shared.open(URL(string: UIApplication.openSettingsURLString)!)
})
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel) { action in
completionHandler(false)
})
let vc = UIApplication.getPresentedViewController()
vc!.present(alert, animated: true)
}
}
extension UIApplication{
class func getPresentedViewController() -> UIViewController? {
var presentViewController = UIApplication.shared.keyWindow?.rootViewController
while let pVC = presentViewController?.presentedViewController
{
presentViewController = pVC
}
return presentViewController
}
}
这些是产生的调用堆栈：
2019-06-14 15:59:12.220116-0700 Sales Networker[805:28798] [Rx] A promise was finished with a nil error.
2019-06-14 15:59:12.226500-0700 Sales Networker[805:28798] [Rx] Call stack: (
0 ContactsFoundation 0x000000012242312a -[CNFuture finishWithError:] + 52
1 Contacts 0x000000010e0c2a82 __55-[CNDataMapperContactStore requestAccessForEntityType:]_block_invoke_2 + 187
2 Contacts 0x000000010e0ffc71 +[CNAuthorization requestAccessForEntityType:completionHandler:] + 77
3 Contacts 0x000000010e072c44 -[CNXPCDataMapper requestAccessForEntityType:completionHandler:] + 123
4 Contacts 0x000000010e0c299a __55-[CNDataMapperContactStore requestAccessForEntityType:]_block_invoke + 174
5 libsystem_trace.dylib 0x000000011269cf00 os_activity_apply_f + 66
6 Contacts 0x000000010e116d52 -[_CNContactsLogger requestingAccessForContacts:] + 225
7 Contacts 0x000000010e0c28a4 -[CNDataMapperContactStore requestAccessForEntityType:] + 177
8 Contacts 0x000000010e09b77f -[CNContactStore requestAccessForEntityType:completionHandler:] + 54
9 Sales Networker 0x000000010ccaadc7 $s15Sales_Networker17ContactsAppHelperC17checkAccessStatusyyySbcF + 535
10 Sales Networker 0x000000010cce9673 $s15Sales_Networker24OnBoardingViewControllerC17rightButtonTappedyySo8UIButtonCF + 451
11 Sales Networker 0x000000010cce9ddc $s15Sales_Networker24OnBoardingViewControllerC17rightButtonTappedyySo8UIButtonCFTo + 60
12 UIKitCore 0x0000000119c7d204 -[UIApplication sendAction:to:from:forEvent:] + 83
13 UIKitCore 0x00000001196d2c19 -[UIControl sendAction:to:forEvent:] + 67
14 UIKitCore 0x00000001196d2f36 -[UIControl _sendActionsForEvents:withEvent:] + 450
15 UIKitCore 0x00000001196d1eec -[UIControl touchesEnded:withEvent:] + 583
16 UIKitCore 0x0000000119cb5eee -[UIWindow _sendTouchesForEvent:] + 2547
17 UIKitCore 0x0000000119cb75d2 -[UIWindow sendEvent:] + 4079
18 UIKitCore 0x0000000119c95d16 -[UIApplication sendEvent:] + 356
19 UIKitCore 0x0000000119d66293 __dispatchPreprocessedEventFromEventQueue + 3232
20 UIKitCore 0x0000000119d68bb9 __handleEventQueueInternal + 5911
21 CoreFoundation 0x000000010ebd6be1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
22 CoreFoundation 0x000000010ebd6463 __CFRunLoopDoSources0 + 243
23 CoreFoundation 0x000000010ebd0b1f __CFRunLoopRun + 1231
24 CoreFoundation 0x000000010ebd0302 CFRunLoopRunSpecific + 626
25 GraphicsServices 0x0000000114a702fe GSEventRunModal + 65
26 UIKitCore 0x0000000119c7bba2 UIApplicationMain + 140
27 Sales Networker 0x000000010cca7f6b main + 75
28 libdyld.dylib 0x0000000112416541 start + 1
)
2019-06-14 15:59:12.236494-0700 Sales Networker[805:28798] [Rx] A promise was finished incorrectly.
2019-06-14 15:59:12.236582-0700 Sales Networker[805:28798] [Rx] Result: (null)
2019-06-14 15:59:12.236669-0700 Sales Networker[805:28798] [Rx] Error : (null)
2019-06-14 15:59:12.238150-0700 Sales Networker[805:28798] [Rx] Call stack: (
0 ContactsFoundation 0x0000000122422ed8 -[CNFuture finishWithResult:error:] + 290
1 Contacts 0x000000010e0c2a82 __55-[CNDataMapperContactStore requestAccessForEntityType:]_block_invoke_2 + 187
2 Contacts 0x000000010e0ffc71 +[CNAuthorization requestAccessForEntityType:completionHandler:] + 77
3 Contacts 0x000000010e072c44 -[CNXPCDataMapper requestAccessForEntityType:completionHandler:] + 123
4 Contacts 0x000000010e0c299a __55-[CNDataMapperContactStore requestAccessForEntityType:]_block_invoke + 174
5 libsystem_trace.dylib 0x000000011269cf00 os_activity_apply_f + 66
6 Contacts 0x000000010e116d52 -[_CNContactsLogger requestingAccessForContacts:] + 225
7 Contacts 0x000000010e0c28a4 -[CNDataMapperContactStore requestAccessForEntityType:] + 177
8 Contacts 0x000000010e09b77f -[CNContactStore requestAccessForEntityType:completionHandler:] + 54
9 Sales Networker 0x000000010ccaadc7 $s15Sales_Networker17ContactsAppHelperC17checkAccessStatusyyySbcF + 535
10 Sales Networker 0x000000010cce9673 $s15Sales_Networker24OnBoardingViewControllerC17rightButtonTappedyySo8UIButtonCF + 451
11 Sales Networker 0x000000010cce9ddc $s15Sales_Networker24OnBoardingViewControllerC17rightButtonTappedyySo8UIButtonCFTo + 60
12 UIKitCore 0x0000000119c7d204 -[UIApplication sendAction:to:from:forEvent:] + 83
13 UIKitCore 0x00000001196d2c19 -[UIControl sendAction:to:forEvent:] + 67
14 UIKitCore 0x00000001196d2f36 -[UIControl _sendActionsForEvents:withEvent:] + 450
15 UIKitCore 0x00000001196d1eec -[UIControl touchesEnded:withEvent:] + 583
16 UIKitCore 0x0000000119cb5eee -[UIWindow _sendTouchesForEvent:] + 2547
17 UIKitCore 0x0000000119cb75d2 -[UIWindow sendEvent:] + 4079
18 UIKitCore 0x0000000119c95d16 -[UIApplication sendEvent:] + 356
19 UIKitCore 0x0000000119d66293 __dispatchPreprocessedEventFromEventQueue + 3232
20 UIKitCore 0x0000000119d68bb9 __handleEventQueueInternal + 5911
21 CoreFoundation 0x000000010ebd6be1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
22 CoreFoundation 0x000000010ebd6463 __CFRunLoopDoSources0 + 243
23 CoreFoundation 0x000000010ebd0b1f __CFRunLoopRun + 1231
24 CoreFoundation 0x000000010ebd0302 CFRunLoopRunSpecific + 626
25 GraphicsServices 0x0000000114a702fe GSEventRunModal + 65
26 UIKitCore 0x0000000119c7bba2 UIApplicationMain + 140
27 Sales Networker 0x000000010cca7f6b main + 75
28 libdyld.dylib 0x0000000112416541 start + 1
)
我测试了你的代码，发现这里发生了两件事。
首先是当您调用 requestAccess(for:completion:) 时状态已经是 .denied，您会在控制台上得到一个 non-fatal 堆栈跟踪。您可以忽略此问题，也可以仅在 .notDetermined 状态下请求访问权限。
第二个问题与主队列上的同步调度有关。由于某种原因，这会导致访问冲突。解决方案是使用 asynchronous 调度。无论如何都没有充分的理由阻止调用队列。
func checkAccessStatus(_ completionHandler: @escaping (_ accessGranted: Bool) -> Void) {
let authorizationStatus = CNContactStore.authorizationStatus(for: .contacts)
switch authorizationStatus {
case .authorized:
completionHandler(true)
case .denied:
self.showSettingsAlert(completionHandler)
case .notDetermined:
store.requestAccess(for: .contacts, completionHandler: { (access, accessError) -> Void in
if access {
completionHandler(access)
}
else {
print("access denied")
self.showSettingsAlert(completionHandler)
}
})
default:
completionHandler(false)
}
}
private func showSettingsAlert(_ completionHandler: @escaping (_ accessGranted: Bool) -> Void) {
let msg = "This app requires access to Contacts to proceed. Would you like to open settings and grant permission?"
let alert = UIAlertController(title: nil, message: msg, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Open Settings", style: .default) { action in
completionHandler(false)
UIApplication.shared.open(URL(string: UIApplication.openSettingsURLString)!)
})
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel) { action in
completionHandler(false)
})
DispatchQueue.main.async {
if let vc = UIApplication.getPresentedViewController() {
vc.present(alert, animated: true)
} else {
completionHandler(false)
}
}
}
这个错误会在两种情况下出现。
当您向用户请求联系权限时，用户拒绝了。
用户已获得联系权限，稍后进入 settings -> your app > off contact permission。
在日志中的这两种情况下，您将看到“承诺已完成，但出现零错误”。
根据客户要求，您可以显示权限被拒绝警报，也可以忽略它。
我正在构建一个 UI 以请求访问 CNContactStore 并处理用户先前（并且可能错误地）拒绝访问的情况。当我检测到当前状态为 .denied 时，我会显示一个 UIAlertController，解释并提议将它们带到应用程序设置以允许访问。
在当前状态为 .denied 的情况下调用 store.requestAccess() 时，应用程序崩溃并显示两个错误：1) "A promise was finished with a nil error." 和 2) "A promise was finished incorrectly."。调用堆栈如下所示。
我不擅长解释调用堆栈，但我认为错误来自 CNContactStore 内部。我不清楚我能做些什么来防止这个错误。
编辑：我根本没有在我的应用程序中使用承诺链。
EDIT2：上面明确说明了我的代码中发生错误的确切位置。
import UIKit
import Contacts
import ContactsUI
final class ContactsAppHelper {
static let shared = ContactsAppHelper()
var store = CNContactStore()
func checkAccessStatus(_ completionHandler: @escaping (_ accessGranted: Bool) -> Void) {
let authorizationStatus = CNContactStore.authorizationStatus(for: .contacts)
switch authorizationStatus {
case .authorized:
completionHandler(true)
case .denied, .notDetermined:
store.requestAccess(for: .contacts, completionHandler: { (access, accessError) -> Void in
if access {
completionHandler(access)
}
else {
print("access denied")
DispatchQueue.main.sync {
self.showSettingsAlert(completionHandler)
}
}
})
default:
completionHandler(false)
}
}
private func showSettingsAlert(_ completionHandler: @escaping (_ accessGranted: Bool) -> Void) {
let msg = "This app requires access to Contacts to proceed. Would you like to open settings and grant permission?"
let alert = UIAlertController(title: nil, message: msg, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Open Settings", style: .default) { action in
completionHandler(false)
UIApplication.shared.open(URL(string: UIApplication.openSettingsURLString)!)
})
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel) { action in
completionHandler(false)
})
let vc = UIApplication.getPresentedViewController()
vc!.present(alert, animated: true)
}
}
extension UIApplication{
class func getPresentedViewController() -> UIViewController? {
var presentViewController = UIApplication.shared.keyWindow?.rootViewController
while let pVC = presentViewController?.presentedViewController
{
presentViewController = pVC
}
return presentViewController
}
}
这些是产生的调用堆栈：
2019-06-14 15:59:12.220116-0700 Sales Networker[805:28798] [Rx] A promise was finished with a nil error.
2019-06-14 15:59:12.226500-0700 Sales Networker[805:28798] [Rx] Call stack: (
0 ContactsFoundation 0x000000012242312a -[CNFuture finishWithError:] + 52
1 Contacts 0x000000010e0c2a82 __55-[CNDataMapperContactStore requestAccessForEntityType:]_block_invoke_2 + 187
2 Contacts 0x000000010e0ffc71 +[CNAuthorization requestAccessForEntityType:completionHandler:] + 77
3 Contacts 0x000000010e072c44 -[CNXPCDataMapper requestAccessForEntityType:completionHandler:] + 123
4 Contacts 0x000000010e0c299a __55-[CNDataMapperContactStore requestAccessForEntityType:]_block_invoke + 174
5 libsystem_trace.dylib 0x000000011269cf00 os_activity_apply_f + 66
6 Contacts 0x000000010e116d52 -[_CNContactsLogger requestingAccessForContacts:] + 225
7 Contacts 0x000000010e0c28a4 -[CNDataMapperContactStore requestAccessForEntityType:] + 177
8 Contacts 0x000000010e09b77f -[CNContactStore requestAccessForEntityType:completionHandler:] + 54
9 Sales Networker 0x000000010ccaadc7 $s15Sales_Networker17ContactsAppHelperC17checkAccessStatusyyySbcF + 535
10 Sales Networker 0x000000010cce9673 $s15Sales_Networker24OnBoardingViewControllerC17rightButtonTappedyySo8UIButtonCF + 451
11 Sales Networker 0x000000010cce9ddc $s15Sales_Networker24OnBoardingViewControllerC17rightButtonTappedyySo8UIButtonCFTo + 60
12 UIKitCore 0x0000000119c7d204 -[UIApplication sendAction:to:from:forEvent:] + 83
13 UIKitCore 0x00000001196d2c19 -[UIControl sendAction:to:forEvent:] + 67
14 UIKitCore 0x00000001196d2f36 -[UIControl _sendActionsForEvents:withEvent:] + 450
15 UIKitCore 0x00000001196d1eec -[UIControl touchesEnded:withEvent:] + 583
16 UIKitCore 0x0000000119cb5eee -[UIWindow _sendTouchesForEvent:] + 2547
17 UIKitCore 0x0000000119cb75d2 -[UIWindow sendEvent:] + 4079
18 UIKitCore 0x0000000119c95d16 -[UIApplication sendEvent:] + 356
19 UIKitCore 0x0000000119d66293 __dispatchPreprocessedEventFromEventQueue + 3232
20 UIKitCore 0x0000000119d68bb9 __handleEventQueueInternal + 5911
21 CoreFoundation 0x000000010ebd6be1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
22 CoreFoundation 0x000000010ebd6463 __CFRunLoopDoSources0 + 243
23 CoreFoundation 0x000000010ebd0b1f __CFRunLoopRun + 1231
24 CoreFoundation 0x000000010ebd0302 CFRunLoopRunSpecific + 626
25 GraphicsServices 0x0000000114a702fe GSEventRunModal + 65
26 UIKitCore 0x0000000119c7bba2 UIApplicationMain + 140
27 Sales Networker 0x000000010cca7f6b main + 75
28 libdyld.dylib 0x0000000112416541 start + 1
)
2019-06-14 15:59:12.236494-0700 Sales Networker[805:28798] [Rx] A promise was finished incorrectly.
2019-06-14 15:59:12.236582-0700 Sales Networker[805:28798] [Rx] Result: (null)
2019-06-14 15:59:12.236669-0700 Sales Networker[805:28798] [Rx] Error : (null)
2019-06-14 15:59:12.238150-0700 Sales Networker[805:28798] [Rx] Call stack: (
0 ContactsFoundation 0x0000000122422ed8 -[CNFuture finishWithResult:error:] + 290
1 Contacts 0x000000010e0c2a82 __55-[CNDataMapperContactStore requestAccessForEntityType:]_block_invoke_2 + 187
2 Contacts 0x000000010e0ffc71 +[CNAuthorization requestAccessForEntityType:completionHandler:] + 77
3 Contacts 0x000000010e072c44 -[CNXPCDataMapper requestAccessForEntityType:completionHandler:] + 123
4 Contacts 0x000000010e0c299a __55-[CNDataMapperContactStore requestAccessForEntityType:]_block_invoke + 174
5 libsystem_trace.dylib 0x000000011269cf00 os_activity_apply_f + 66
6 Contacts 0x000000010e116d52 -[_CNContactsLogger requestingAccessForContacts:] + 225
7 Contacts 0x000000010e0c28a4 -[CNDataMapperContactStore requestAccessForEntityType:] + 177
8 Contacts 0x000000010e09b77f -[CNContactStore requestAccessForEntityType:completionHandler:] + 54
9 Sales Networker 0x000000010ccaadc7 $s15Sales_Networker17ContactsAppHelperC17checkAccessStatusyyySbcF + 535
10 Sales Networker 0x000000010cce9673 $s15Sales_Networker24OnBoardingViewControllerC17rightButtonTappedyySo8UIButtonCF + 451
11 Sales Networker 0x000000010cce9ddc $s15Sales_Networker24OnBoardingViewControllerC17rightButtonTappedyySo8UIButtonCFTo + 60
12 UIKitCore 0x0000000119c7d204 -[UIApplication sendAction:to:from:forEvent:] + 83
13 UIKitCore 0x00000001196d2c19 -[UIControl sendAction:to:forEvent:] + 67
14 UIKitCore 0x00000001196d2f36 -[UIControl _sendActionsForEvents:withEvent:] + 450
15 UIKitCore 0x00000001196d1eec -[UIControl touchesEnded:withEvent:] + 583
16 UIKitCore 0x0000000119cb5eee -[UIWindow _sendTouchesForEvent:] + 2547
17 UIKitCore 0x0000000119cb75d2 -[UIWindow sendEvent:] + 4079
18 UIKitCore 0x0000000119c95d16 -[UIApplication sendEvent:] + 356
19 UIKitCore 0x0000000119d66293 __dispatchPreprocessedEventFromEventQueue + 3232
20 UIKitCore 0x0000000119d68bb9 __handleEventQueueInternal + 5911
21 CoreFoundation 0x000000010ebd6be1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
22 CoreFoundation 0x000000010ebd6463 __CFRunLoopDoSources0 + 243
23 CoreFoundation 0x000000010ebd0b1f __CFRunLoopRun + 1231
24 CoreFoundation 0x000000010ebd0302 CFRunLoopRunSpecific + 626
25 GraphicsServices 0x0000000114a702fe GSEventRunModal + 65
26 UIKitCore 0x0000000119c7bba2 UIApplicationMain + 140
27 Sales Networker 0x000000010cca7f6b main + 75
28 libdyld.dylib 0x0000000112416541 start + 1
)
我测试了你的代码，发现这里发生了两件事。
首先是当您调用 requestAccess(for:completion:) 时状态已经是 .denied，您会在控制台上得到一个 non-fatal 堆栈跟踪。您可以忽略此问题，也可以仅在 .notDetermined 状态下请求访问权限。
第二个问题与主队列上的同步调度有关。由于某种原因，这会导致访问冲突。解决方案是使用 asynchronous 调度。无论如何都没有充分的理由阻止调用队列。
func checkAccessStatus(_ completionHandler: @escaping (_ accessGranted: Bool) -> Void) {
let authorizationStatus = CNContactStore.authorizationStatus(for: .contacts)
switch authorizationStatus {
case .authorized:
completionHandler(true)
case .denied:
self.showSettingsAlert(completionHandler)
case .notDetermined:
store.requestAccess(for: .contacts, completionHandler: { (access, accessError) -> Void in
if access {
completionHandler(access)
}
else {
print("access denied")
self.showSettingsAlert(completionHandler)
}
})
default:
completionHandler(false)
}
}
private func showSettingsAlert(_ completionHandler: @escaping (_ accessGranted: Bool) -> Void) {
let msg = "This app requires access to Contacts to proceed. Would you like to open settings and grant permission?"
let alert = UIAlertController(title: nil, message: msg, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Open Settings", style: .default) { action in
completionHandler(false)
UIApplication.shared.open(URL(string: UIApplication.openSettingsURLString)!)
})
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel) { action in
completionHandler(false)
})
DispatchQueue.main.async {
if let vc = UIApplication.getPresentedViewController() {
vc.present(alert, animated: true)
} else {
completionHandler(false)
}
}
}
这个错误会在两种情况下出现。
当您向用户请求联系权限时，用户拒绝了。
用户已获得联系权限，稍后进入
settings -> your app > off contact permission。
在日志中的这两种情况下，您将看到“承诺已完成，但出现零错误”。 根据客户要求，您可以显示权限被拒绝警报，也可以忽略它。