我在 Xcode 8 Beta 6 (8S201h) 中写了这个:
guard let faceMembers = NSFontManager.shared().availableMembers(ofFontFamily: familyName ?? fontName) else { return nil }
它工作得很好。现在我已经升级到 Xcode 8 GM Seed (8A218a) Xcode 8 (8A218a)，它崩溃了 (
EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) )。使用调试器缩小范围，我发现
NSFontManager.availableMembers(ofFontFamily:) 中的某些东西真的很讨厌这个，因为无论我在那里放什么它都会崩溃，即使是像 Helvetica Neue 这样的常见(肯定安装了!)字体。(lldb) po NSFontManager.shared()
<NSFontManager: 0x6100000a24c0>
(lldb) po familyName
▿ Optional<String>
- some : "Helvetica Neue"
(lldb) po fontName
"HelveticaNeue"
(lldb) po NSFontManager.shared().availableMembers(ofFontFamily: familyName ?? fontName)
error: Execution was interrupted, reason: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0).
The process has been returned to the state before expression evaluation.
(lldb) po NSFontManager.shared().availableMembers(ofFontFamily: familyName!)
error: Execution was interrupted, reason: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0).
The process has been returned to the state before expression evaluation.
(lldb) po NSFontManager.shared().availableMembers(ofFontFamily: "Not a real font?!")
nil
所以当我传递一个有效的字体系列名称时，它会崩溃……但是当我传递一个假的时，它返回
nil 。这是我可以解决的问题，还是 Xcode 8 GM Seed Xcode 8 的问题，将在 SDK 更新中解决？
在查看崩溃日志后，我看到了这个可疑之处:
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 libswiftFoundation.dylib 0x0000000107cbb249 _TZFE10FoundationSa26_forceBridgeFromObjectiveCfTCSo7NSArray6resultRGSqGSax___T_ + 153
1 libswiftCore.dylib 0x00000001079031f3 swift_dynamicCast + 1635
2 libswiftCore.dylib 0x000000010790448b _dynamicCastFromExistential(swift::OpaqueValue*, swift::OpaqueValue*, swift::TargetExistentialTypeMetadata<swift::InProcess> const*, swift::TargetMetadata<swift::InProcess> const*, swift::DynamicCastFlags) + 91
3 libswiftCore.dylib 0x0000000107903919 swift_dynamicCast + 3465
4 libswiftFoundation.dylib 0x0000000107d6a348 _TPA__TFFs15_arrayForceCastu0_rFGSax_GSaq__U_FQ_Q0_ + 56
5 libswiftFoundation.dylib 0x0000000107cbbc45 _TFEsPs10Collection3mapurfzFzWx8Iterator7Element_qd__GSaqd___ + 885
6 libswiftFoundation.dylib 0x0000000107cbb4c3 _TFs15_arrayForceCastu0_rFGSax_GSaq__ + 227
7 libswiftFoundation.dylib 0x0000000107cbb7a5 _TZFE10FoundationSa36_unconditionallyBridgeFromObjectiveCfGSqCSo7NSArray_GSax_ + 197
所以它似乎在 Swift-Foundation 中崩溃了，在一些名为
_forceBridgeFromObjectiveC 的函数中......不确定这是否对任何人有帮助，但它确实确认它在 SDK/运行时内。 最佳答案
与此同时，我能弄清楚如何解决这个问题的唯一方法是在 Objective-c 类中创建一个静态方法。然后我将 header 导入到我的桥接头中，并从 Swift 3 中调用了静态方法，它运行良好。
希望这能帮助您度过这些困难时期!
#import <Foundation/Foundation.h>
#import <Cocoa/Cocoa.h>
@interface WorkAround : NSObject
+ (NSArray *)typefacesForFontFamily:(NSString *)family;
@end
#import "WorkAround.h"
@implementation WorkAround
/// Returns an array of arrays, or nil, that contain information about
/// each typeface found for the specified font family.
+ (NSArray *)typefacesForFontFamily:(nonnull NSString *)family {
NSFontManager *fontManager = [NSFontManager sharedFontManager];
return [fontManager availableMembersOfFontFamily:family];
}
@end
关于xcode - 为什么 NSFontManager.availableMembers(ofFontFamily :) crashing in Xcode 8 GM?，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/39395237/