Xcode9中，调试运行iOS的app，看到提示：
runtime: UI API called from background thread: -[UIApplication currentUserNotificationSettings] must be used from main thread only
但是点击后，无法找到具体是哪里的代码。
且项目中也搜不到：
currentUserNotificationSettings
runtime: UI API called from background thread UIApplication currentUserNotificationSettings
Xcode 9 – Main Thread Sanitizer · Issue #69 · firebase/firebase-ios-sdk · GitHub
XCode 9: Main Thread Checker: UI API called from background thread: -[UIApplication applicationIconBadgeNumber] must be called from main thread only · Issue #1146 · parse-community/Parse-SDK-iOS-OSX · GitHub
集成JPush报警告must be used from main thread only – 极光技术 / JPush – 极光社区
去项目里搜：
UIApplication.
没找到JPUSH方面的
原来是：
Xcode9中引入了一个
Main Thread Checker
用于运行时期间检测，是否有其他非主UI线程中，去更新UI元素的代码。
有的话，就警告
当然，如果取消警告，可以取消勾选，但是很明显不推荐。
后来看到：
#0 0x0000000100d22f7f in -[JPUSHAPNSStateReport init] ()
#14 0x0000000182d72c38 in thread_start ()
去搜：
JPUSHAPNSStateReport UIApplication
UI API called on a background thread，UI没再主线程刷新，是不是JPush框架的问题？ – Bug 报告 / 已修复 – 极光社区
好像是JPush的bug
JPush iOS SDK v3.0.6 最近更新 – 极光文档
后来去Xcode的log输出中，找到了：
Main Thread Checker: UI API called on a background thread: -[UIApplication currentUserNotificationSettings] PID: 820, TID: 444196, Thread name: org.hxhg.jiguang.thread, Queue name: com.apple.root.default-qos.overcommit, QoS: 21 Backtrace: 4 SRTDev 0x0000000100d22f80 -[JPUSHAPNSStateReport init] + 232 5 SRTDev 0x0000000100d26d68 -[JPUSHClientController UDPReportAPNSState] + 44 6 SRTDev 0x0000000100d26610 -[JPUSHClientController setup] + 484 7 Foundation 0x0000000183b37a50 <redacted> + 340 8 CoreFoundation 0x00000001830f0358 <redacted> + 24 9 CoreFoundation 0x00000001830f02d8 <redacted> + 88 10 CoreFoundation 0x00000001830efb60 <redacted> + 204 11 CoreFoundation 0x00000001830ed738 <redacted> + 1048 12 CoreFoundation 0x000000018300e2d8 CFRunLoopRunSpecific + 436 13 CoreFoundation 0x000000018305d12c CFRunLoopRun + 116 14 SRTDev 0x0000000100cf2154 -[JPUSHThread clientThreadMain] + 100 15 Foundation 0x0000000183b37860 <redacted> + 996 16 libsystem_pthread.dylib 0x0000000182d7432c <redacted> + 308 17 libsystem_pthread.dylib 0x0000000182d741f8 <redacted> + 0 18 libsystem_pthread.dylib 0x0000000182d72c38 thread_start + 4 2017-09-22 11:16:32.041279+0800 SRTDev[820:444196] [reports] Main Thread Checker: UI API called on a background thread: -[UIApplication currentUserNotificationSettings] PID: 820, TID: 444196, Thread name: org.hxhg.jiguang.thread, Queue name: com.apple.root.default-qos.overcommit, QoS: 21 Backtrace: 4 SRTDev 0x0000000100d22f80 -[JPUSHAPNSStateReport init] + 232 5 SRTDev 0x0000000100d26d68 -[JPUSHClientController UDPReportAPNSState] + 44 6 SRTDev 0x0000000100d26610 -[JPUSHClientController setup] + 484 7 Foundation 0x0000000183b37a50 <redacted> + 340 8 CoreFoundation 0x00000001830f0358 <redacted> + 24 9 CoreFoundation 0x00000001830f02d8 <redacted> + 88 10 CoreFoundation 0x00000001830efb60 <redacted> + 204 11 CoreFoundation 0x00000001830ed738 <redacted> + 1048 12 CoreFoundation 0x000000018300e2d8 CFRunLoopRunSpecific + 436 13 CoreFoundation 0x000000018305d12c CFRunLoopRun + 116 14 SRTDev 0x0000000100cf2154 -[JPUSHThread clientThreadMain] + 100 15 Foundation 0x0000000183b37860 <redacted> + 996 16 libsystem_pthread.dylib 0x0000000182d7432c <redacted> + 308 17 libsystem_pthread.dylib 0x0000000182d741f8 <redacted> + 0 18 libsystem_pthread.dylib 0x0000000182d72c38 thread_start + 4 |
所以，去升级JPush
-》
https://sdkfiledl.jiguang.cn/jpush-ios-3.0.6-release.zip?t=1506059605006
放到项目中，替换旧版本
之前版本是：
<code>--------------------------- JPush Log ---------------------------- --------------------JPush SDK Version:3.0.1--build:21---------- --------------------JCore Lib Version:1.1.0--build:8————— </code>
结果换成3.0.6的库后，链接失败：
【总结】
把JPush从3.0.1升级到3.0.6，好像上述警告就没了。
（但是貌似回退到3.0.1，貌似也没有问题？先不去管了。。。）
转载请注明：在路上 » 【已解决】Xcode9提示：runtime UI API called from background thread UIApplication currentUserNotificationSettings must be used from main thread only