-[WKWebView _cancelOperation:]：无法识别的选择器发送到实例 - 在 WkWebview 输入上按“ESC”时

Question

处理出现此异常的问题：

异常 NSException *“-[App.MyBrandWebView _cancelOperation:]：无法识别的选择器发送到实例 0x119027400”0x0000600000cfb9c0

每当在 WkWebView 中的输入中键入“ESC”键时抛出该错误。对于上下文，这是一个基于混合 Web 视图的应用程序，我们正在使用自定义 WKWebView 超类。

最初，我认为这个问题是微不足道的，可以通过在

_cancelOperation

子类上定义这个

MyBrandWebView

函数来解决，但这似乎没有效果：

class MyBrandWebView: WKWebView {

  @objc func _cancelOperation(sender: Any?) {
    
  }
  
  
  @objc func cancelOperation(sender: Any?) {
    
  }
}

我正在查看

WKWebView

的继承链，我很难弄清楚这个

cancelOperation

是在哪里定义的，或者更重要的是，为什么它是用转义键触发的。

这是相关的堆栈跟踪

*** First throw call stack:
(
    0   CoreFoundation                      0x00000001804658a8 __exceptionPreprocess + 172
    1   libobjc.A.dylib                     0x000000018005c09c objc_exception_throw + 56
    2   CoreFoundation                      0x000000018047a6f8 +[NSObject(NSObject) instanceMethodSignatureForSelector:] + 0
    3   UIKitCore                           0x0000000110a7b3d4 -[UIResponder doesNotRecognizeSelector:] + 232
    4   CoreFoundation                      0x00000001804699f8 ___forwarding___ + 1280
    5   CoreFoundation                      0x000000018046bd1c _CF_forwarding_prep_0 + 92
    6   UIKitCore                           0x000000011084fe28 -[UIKeyboardImpl _cancelOperation:testOnly:] + 636
    7   UIKitCore                           0x00000001108512a8 -[UIKeyboardImpl handleKeyCommand:repeatOkay:options:] + 3760
    8   UIKitCore                           0x0000000110880e80 -[UIKeyboardImpl _handleKeyCommandCommon:options:] + 72
    9   UIKitCore                           0x0000000110880e28 -[UIKeyboardImpl _handleKeyCommand:] + 16
    10  UIKitCore                           0x00000001108665b4 -[UIKeyboardImpl handleKeyTextCommandForCurrentEvent] + 236
    11  WebKit                              0x0000000107d8b3bc -[WKContentView(WKInteraction) _interpretKeyEvent:isCharEvent:] + 160
    12  WebKit                              0x000000010789f8c4 _ZN6WebKit14PageClientImpl17interpretKeyEventERKNS_22NativeWebKeyboardEventEb + 48
    13  WebKit                              0x00000001078c4cb0 _ZN6WebKit12WebPageProxy17interpretKeyEventERKNS_11EditorStateEbON3WTF17CompletionHandlerIFvbEEE + 140
    14  WebKit                              0x0000000107cda790 _ZN6WebKit12WebPageProxy21didReceiveSyncMessageERN3IPC10ConnectionERNS1_7DecoderERN3WTF9UniqueRefINS1_7EncoderEEE + 3268
    15  WebKit                              0x0000000107dc260c _ZN3IPC18MessageReceiverMap19dispatchSyncMessageERNS_10ConnectionERNS_7DecoderERN3WTF9UniqueRefINS_7EncoderEEE + 276
    16  WebKit                              0x00000001079eb928 _ZN6WebKit15WebProcessProxy21didReceiveSyncMessageERN3IPC10ConnectionERNS1_7DecoderERN3WTF9UniqueRefINS1_7EncoderEEE + 40
    17  WebKit                              0x0000000107dbe6f0 _ZN3IPC10Connection15dispatchMessageENSt3__110unique_ptrINS_7DecoderENS1_14default_deleteIS3_EEEE + 728
    18  WebKit                              0x0000000107dbff58 _ZN3WTF6Detail15CallableWrapperIZN3IPC10Connection16SyncMessageState22processIncomingMessageERS3_RNSt3__110unique_ptrINS2_7DecoderENS6_14default_deleteIS8_EEEEE3$_5vJEE4callEv + 636
    19  JavaScriptCore                      0x000000010d2dc3d4 _ZN3WTF7RunLoop11performWorkEv + 176
    20  JavaScriptCore                      0x000000010d2dd0e4 _ZN3WTF7RunLoop11performWorkEPv + 32
    21  CoreFoundation                      0x00000001803c669c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24
    22  CoreFoundation                      0x00000001803c65e4 __CFRunLoopDoSource0 + 172
    23  CoreFoundation                      0x00000001803c5d54 __CFRunLoopDoSources0 + 232
    24  CoreFoundation                      0x00000001803c043c __CFRunLoopRun + 768
    25  CoreFoundation                      0x00000001803bfd28 CFRunLoopRunSpecific + 572
    26  GraphicsServices                    0x000000018986ebc0 GSEventRunModal + 160
    27  UIKitCore                           0x0000000110a4ffdc -[UIApplication _run] + 868
    28  UIKitCore                           0x0000000110a53c54 UIApplicationMain + 124
    29  App                                 0x00000001001fc684 main + 64
    30  dyld                                0x00000001003d1558 start_sim + 20
    31  ???                                 0x00000001004b6058 0x0 + 4299907160
    32  ???                                 0x8343000000000000 0x0 + 9458403642408173568
)
libc++abi: terminating due to uncaught exception of type NSException

Answer 1

可以通过在子类上定义运行时选择器来使其工作，如下所示：

    let block: @convention(block) (AnyObject?) -> Void = { (self: AnyObject!) -> Void in }
    let imp = imp_implementationWithBlock(unsafeBitCast(block, to: AnyObject.self))
    class_addMethod(MyBrandWebView.self, NSSelectorFromString("_cancelOperation:"), imp, "i@:@")

不认为这是正确的解决方案，但它确实有效。那我就分享一下吧。