點進一個web頁面沒問題，但是返回的時候crash。錯誤信息如下
2017-08-18 19:29:52.734 BluedInternational[11600:1646954] dealloc
objc[11600]: Cannot form weak reference to instance (0x5225200) of class GJWebViewController. It is possible that this object was over-released, or is in the process of deallocation.
(lldb) bt
- thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BREAKPOINT (code=EXC_ARM_BREAKPOINT, subcode=0xdefe)
- frame #0: 0x20bf2a44 libobjc.A.dylib
_objc_trap() frame #1: 0x20bf2aa8 libobjc.A.dylib_objc_fatal(char const, ...) + 72
frame #2: 0x20c0c412 libobjc.A.dylibweak_register_no_lock + 210 frame #3: 0x20c0c7b8 libobjc.A.dylibobjc_storeWeak + 208
frame #4: 0x25a8489a UIKit-[UIScrollView setDelegate:] + 306 frame #5: 0x283c6f30 WebKit-[WKScrollView _updateDelegate] + 228
frame #6: 0x283d09fe WebKit-[WKWebView dealloc] + 266 frame #7: 0x20c0d3a8 libobjc.A.dylib(anonymous namespace)::AutoreleasePoolPage::pop(void) + 388
frame #8: 0x21366f88 CoreFoundation_CFAutoreleasePoolPop + 16 frame #9: 0x2141806e CoreFoundation__CFRunLoopRun + 1582
frame #10: 0x21367228 CoreFoundationCFRunLoopRunSpecific + 520 frame #11: 0x21367014 CoreFoundationCFRunLoopRunInMode + 108
frame #12: 0x22957ac8 GraphicsServicesGSEventRunModal + 160 frame #13: 0x25a3b188 UIKitUIApplicationMain + 144
frame #14: 0x0007cf62 BluedInternationalmain(argc=1, argv=0x0361bab8) at main.m:13 frame #15: 0x2100f872 libdyld.dylibstart + 2
(lldb)
分析發現，在WKWebView釋放之后竟然還進行了scrollView代理的設置，而這個時候的self，也就是當前的控制器處于銷毀當中，也就解釋了上面log提到的or is in the process of deallocation.。所以加入你的WKWebView是懶加載的，不要在懶加載中設置代理，其次在dealloc中將代理置為nil。
遇到記錄下
轉載：http://www.lxweimin.com/p/b3d97cdeb4c5
- frame #0: 0x20bf2a44 libobjc.A.dylib
