ios - swift NSWritingDirection 导致 NSAttributedString 崩溃

Question

我有这样的代码:

let myString = "Swift Attributed String"
let myAttribute = [ NSAttributedStringKey.foregroundColor: UIColor.blue , NSAttributedStringKey.writingDirection:(NSWritingDirection.rightToLeft.rawValue|NSWritingDirectionFormatType.override.rawValue)] as [NSAttributedStringKey : Any]
let myAttrString = NSAttributedString(string: myString, attributes: myAttribute)

// set attributed text on a UILabel
self.labelUsername.attributedText = myAttrString

应用程序在上一行崩溃。如果我从属性字典中删除 NSAttributedStringKey.writingDirection，崩溃就会消失。

这是崩溃日志:

2018-03-20 14:38:59.077 Haraj Swift[90519:25834245] -[__NSCFNumber countByEnumeratingWithState:objects:count:]: unrecognized selector sent to instance 0xb000000000000033
2018-03-20 14:38:59.092 Haraj Swift[90519:25834245] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFNumber countByEnumeratingWithState:objects:count:]: unrecognized selector sent to instance 0xb000000000000033'
*** First throw call stack:
(
    0   CoreFoundation                      0x000000010ef6434b __exceptionPreprocess + 171
    1   libobjc.A.dylib                     0x000000010e9c521e objc_exception_throw + 48
    2   CoreFoundation                      0x000000010efd3f34 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
    3   CoreFoundation                      0x000000010eee9c15 ___forwarding___ + 1013
    4   CoreFoundation                      0x000000010eee9798 _CF_forwarding_prep_0 + 120
    5   UIFoundation                        0x00000001176e13b3 -[NSATSGlyphStorage setGlyphRange:characterRange:] + 2709
    6   UIFoundation                        0x00000001176dc5ec -[NSATSTypesetter _ctTypesetter] + 287
    7   UIFoundation                        0x00000001176e6ef7 -[NSATSLineFragment layoutForStartingGlyphAtIndex:characterIndex:minPosition:maxPosition:lineFragmentRect:] + 95
    8   UIFoundation                        0x00000001176dd540 -[NSATSTypesetter _layoutLineFragmentStartingWithGlyphAtIndex:characterIndex:atPoint:renderingContext:] + 3240
    9   UIFoundation                        0x00000001176eeb84 -[NSSingleLineTypesetter createRenderingContextForCharacterRange:typesetterBehavior:usesScreenFonts:hasStrongRight:syncDirection:mirrorsTextAlignment:maximumWidth:] + 408
    10  UIFoundation                        0x0000000117724167 __NSStringDrawingEngine + 27441
    11  UIFoundation                        0x00000001177263d4 -[NSAttributedString(NSExtendedStringDrawing) boundingRectWithSize:options:context:] + 797
    12  UIKit                               0x000000010fd1f744 -[UILabel _textRectForBounds:limitedToNumberOfLines:includingShadow:] + 1199
    13  UIKit                               0x000000010fd1f05b -[UILabel textRectForBounds:limitedToNumberOfLines:] + 68
    14  UIKit                               0x000000010fd24b7f -[UILabel _intrinsicSizeWithinSize:] + 168
    15  UIKit                               0x000000010fd24c6c -[UILabel intrinsicContentSize] + 92
    16  UIKit                               0x00000001104679ed -[UIView(UIConstraintBasedLayout) _generateContentSizeConstraints] + 35
    17  UIKit                               0x00000001104676ea -[UIView(UIConstraintBasedLayout) _updateContentSizeConstraints] + 494
    18  UIKit                               0x00000001104714d6 -[UIView(AdditionalLayoutSupport) _updateSystemConstraints] + 66
    19  UIKit                               0x000000011046ff3e -[UIView(AdditionalLayoutSupport) _sendUpdateConstraintsIfNecessaryForSecondPass:] + 161
    20  UIKit                               0x000000011047039d -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededCollectingViews:forSecondPass:] + 860
    21  UIKit                               0x00000001104702fa -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededCollectingViews:forSecondPass:] + 697
    22  UIKit                               0x00000001104702fa -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededCollectingViews:forSecondPass:] + 697
    23  Foundation                          0x000000010e4e1bd0 -[NSISEngine withBehaviors:performModifications:] + 155
    24  UIKit                               0x00000001104705f2 -[UIView(AdditionalLayoutSupport) _recursiveUpdateConstraintsIfNeededCollectingViews:forSecondPass:] + 118
    25  UIKit                               0x00000001104702fa -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededCollectingViews:forSecondPass:] + 697
    26  UIKit                               0x00000001104702fa -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededCollectingViews:forSecondPass:] + 697
    27  Foundation                          0x000000010e4e1bd0 -[NSISEngine withBehaviors:performModifications:] + 155
    28  UIKit                               0x0000000110470c71 __97-[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededPostponeVariableChangeNotifications:]_block_invoke + 91
    29  UIKit                               0x000000011046fa9b -[UIView(AdditionalLayoutSupport) _withUnsatisfiableConstraintsLoggingSuspendedIfEngineDelegateExists:] + 117
    30  UIKit                               0x0000000110470757 -[UIView(AdditionalLayoutSupport) _updateConstraintsIfNeededPostponeVariableChangeNotifications:] + 181
    31  UIKit                               0x000000011047184d -[UIView(AdditionalLayoutSupport) _updateConstraintsAtEngineLevelIfNeededPostponeVariableChangeNotifications:] + 356
    32  UIKit                               0x000000010fb4b922 -[UIView(Hierarchy) _updateConstraintsAsNecessaryAndApplyLayoutFromEngine] + 159
    33  UIKit                               0x000000010fb5cf50 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 1237
    34  QuartzCore                          0x0000000117054cc4 -[CALayer layoutSublayers] + 146
    35  QuartzCore                          0x0000000117048788 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 366
    36  QuartzCore                          0x0000000117048606 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
    37  QuartzCore                          0x0000000116fd6680 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 280
    38  QuartzCore                          0x0000000117003767 _ZN2CA11Transaction6commitEv + 475
    39  QuartzCore                          0x00000001170040d7 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 113
    40  CoreFoundation                      0x000000010ef08e17 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
    41  CoreFoundation                      0x000000010ef08d87 __CFRunLoopDoObservers + 391
    42  CoreFoundation                      0x000000010eeedb9e __CFRunLoopRun + 1198
    43  CoreFoundation                      0x000000010eeed494 CFRunLoopRunSpecific + 420
    44  GraphicsServices                    0x0000000116f37a6f GSEventRunModal + 161
    45  UIKit                               0x000000010fa98964 UIApplicationMain + 159
    46  Haraj Swift                         0x000000010de9e8a7 main + 55
    47  libdyld.dylib                       0x0000000112fe168d start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Answer 1

尝试使用 NSWritingDirection 的 array

    let myString = "Swift Attributed String"

    let myAttrString = NSAttributedString(string: myString, attributes: [.foregroundColor : UIColor.blue, .writingDirection: [NSWritingDirection.rightToLeft.rawValue]])

    self.label.attributedText = myAttrString

如果您仍然遇到任何问题，请告诉我。