Question

以下是我的某个应用中发生的崩溃的堆栈跟踪。我不知道如何解决它并且它不会总是发生？请帮助:)）

它与Swift Generics有关吗？

    Thread : Crashed: com.apple.main-thread
0  MyApp                         0x1000f4f5c specialized FriendsTableViewController.tableView(UITableView, cellForRowAtIndexPath : NSIndexPath) -> UITableViewCell (FriendsTableViewController.swift)
1  MyApp                         0x1000f1f60 @objc FriendsTableViewController.tableView(UITableView, cellForRowAtIndexPath : NSIndexPath) -> UITableViewCell (FriendsTableViewController.swift)
2  UIKit                          0x1867ad31c -[UITableView _createPreparedCellForGlobalRow:withIndexPath:willDisplay:] + 692
3  UIKit                          0x1867ad484 -[UITableView _createPreparedCellForGlobalRow:willDisplay:] + 80
4  UIKit                          0x18679c9b8 -[UITableView _updateVisibleCellsNow:isRecursive:] + 2824
5  UIKit                          0x186539208 -[UITableView _setNeedsVisibleCellsUpdate:withFrames:] + 240
6  UIKit                          0x1865390d0 -[UITableView _rectChangedWithNewSize:oldSize:] + 996
7  UIKit                          0x186546df4 -[UITableView setBounds:] + 256
8  UIKit                          0x18647a2bc -[UIScrollView setContentOffset:] + 424
9  UIKit                          0x1865382bc -[UITableView setContentOffset:] + 300
10 UIKit                          0x186780a3c -[UIScrollView(UIScrollViewInternal) _adjustContentOffsetIfNecessary] + 60
11 UIKit                          0x18677ab5c -[UIScrollView _updateForChangedScrollRelatedInsets] + 48
12 UIKit                          0x18651d5ac -[UIScrollView setContentInset:] + 116
13 UIKit                          0x186546c50 -[UITableView setContentInset:] + 132
14 UIKit                          0x1865bf250 -[UIScrollView(UIScrollViewInternal) _adjustForAutomaticKeyboardInfo:animated:lastAdjustment:] + 348
15 UIKit                          0x1865bf0b8 -[UITableView _adjustForAutomaticKeyboardInfo:animated:lastAdjustment:] + 108
16 UIKit                          0x186d50380 -[UIAutoRespondingScrollViewControllerKeyboardSupport _adjustScrollViewForKeyboardInfo:] + 288
17 Foundation                     0x18211e44c __NSFireDelayedPerform + 428
18 CoreFoundation                 0x1817215f4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 28
19 CoreFoundation                 0x181721298 __CFRunLoopDoTimer + 884
20 CoreFoundation                 0x18171e9ac __CFRunLoopRun + 1520
21 CoreFoundation                 0x18164d680 CFRunLoopRunSpecific + 384
22 GraphicsServices               0x182b5c088 GSEventRunModal + 180
23 UIKit                          0x1864c4d90 UIApplicationMain + 204
24 MyApp                         0x100094ef8 main (AppDelegate.swift:15)
25 libdispatch.dylib              0x1811ee8b8 (Missing

除此之外，这是我拥有的cellForRow函数

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    if indexPath.section < 2 {
        let cell = tableView.dequeueReusableCellWithIdentifier("FriendCell", forIndexPath: indexPath) as! FriendTableViewCell
        cell.tag = indexPath.row

        var user: TetherUser!

        if searching {
            user = searchedUsers[indexPath.row]
        } else {
            if indexPath.section == 0 {
                user = users[indexPath.row]
                cell.actionButton.friendIsContact = false
            } else if indexPath.section == 1 {
                user = contactsWithApp[indexPath.row]
                cell.actionButton.friendIsContact = true
            }
        }

        user.tag = indexPath.row

        cell.nameLabel.text = user.fullName
        cell.profileImageView.image = nil
        user.profileImage { (image) -> Void in
            if user.tag == cell.tag {
                cell.profileImageView.image = image
            }
        }

        if let currentUserID = TetherManager.sharedInstance.currentTetherUser?.objectId {
            cell.actionButton.type = user.relationToUserWithID(currentUserID)
            cell.actionButton.tag = indexPath.row
            cell.actionButton.delegate = self
            switch user.relationToUserWithID(currentUserID) {
            case .None:
                cell.actionButton.button.setImage(UIImage(named: "AddFriend"), forState: .Normal)
                break
            case .SentFriendRequest:
                cell.actionButton.button.setImage(UIImage(named: "ReceivedFriendRequest"), forState: .Normal)
                break
            case .ReceivedFriendRequest:
                cell.actionButton.button.setImage(UIImage(named: "PendingFriendRequest"), forState: .Normal)
                break
            case .Friends:
                cell.actionButton.button.setImage(UIImage(named: "RemoveFriend"), forState: .Normal)
                break
            }
        }
        return cell
    } else {
        //Contacts
        let cell = tableView.dequeueReusableCellWithIdentifier("ContactCell", forIndexPath: indexPath) as! ContactTableViewCell
        cell.contact = addressBookContacts[indexPath.row]
        cell.delegate = self
        return cell
    }
}

Answer 1

您需要为indexPath.section == 2创建案例的User对象，因为您有3个部分。您需要确保在此代码块中正确初始化'user'对象（请参阅代码中的内联注释）

    var user: TetherUser!

    if searching {
        user = searchedUsers[indexPath.row]
    } else {
        if indexPath.section == 0 {
            user = users[indexPath.row]
            cell.actionButton.friendIsContact = false
        } else if indexPath.section == 1 {
            user = contactsWithApp[indexPath.row]
            cell.actionButton.friendIsContact = true
        } else if indexPath.section == 2 {
         // Add code here to ensure user has proper value.
        }
    }

Answer 2

我有这个＆＃34;专业＆＃34;错误也。崩溃只发生在iOS 8.0和8.1上。这是我的堆栈跟踪的一部分。

Crashed: com.apple.main-thread
0  Viki                           0x10027bb28 specialized LoginFlowSocialButton.traitCollectionDidChange(UITraitCollection?) -> () + 4297243432
1  Viki                           0x10027ad30 @objc LoginFlowSocialButton.traitCollectionDidChange(UITraitCollection?) -> () (LoginFlowButton.swift)
2  UIKit                          0x18a696cd4 -[UIView _processTraitsDidChangeRecursively:forceNotification:] + 124
3  UIKit                          0x18a3d05f4 __45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke + 348
4  UIKit                          0x18a3d0408 -[UIView(Hierarchy) _postMovedFromSuperview:] + 484
5  UIKit                          0x18a3dbea4 -[UIView(Internal) _addSubview:positioned:relativeTo:] + 1724
6  UIKit                          0x18a694f34 -[UIView initWithCoder:] + 756
...

我尝试下载这些版本的iOS模拟器之一并再次测试。事实证明，崩溃来自使用强制解包的var，但在nil函数中找到了traitCollectionDidChange。

所以这里的教训只是错误消息中的specialized函数可能不指向确切的问题。您可以尝试查看该功能，看看那里出了什么问题。

希望有所帮助。：）

斯威夫特＆＃34;专业＆＃34;紧急

2 个答案: