Xcode 构建在设备上运行但在模拟器上失败

Question

我将 CocoaPods 与 React Native 应用程序一起使用。在 Xcode 模拟器中运行构建时，我遇到了各种错误。我在我的设备上运行它没有问题。这是我启用断点后得到的：

- (void)ensureOnJavaScriptThread:(dispatch_block_t)block
    {
      RCTAssert(_jsThread, @"This method must not be called before the JS thread is created");

这里的错误是绿色的（但是很糟糕，感谢 Xcode），上面写着 com.facebook.react.JavaScript (9): breakpoint 1.2

禁用断点时出现两个错误，这是一个：

void Instance::loadApplication(std::unique_ptr<RAMBundleRegistry> bundleRegistry,
                                   std::unique_ptr<const JSBigString> string,
                                   std::string sourceURL) {
      callback_->incrementPendingJSCalls();
      SystraceSection s("Instance::loadApplication", "sourceURL",
                        sourceURL);
      nativeToJsBridge_->loadApplication(std::move(bundleRegistry), std::move(string),
                                         std::move(sourceURL));
    }

callback_-> 行上的红色错误为 EXC_BAD_ACCESS (code=EXC_I386_GPFLT)

第二个是此代码中的signal SIGABRT 错误：

int main(int argc, char * argv[]) { 
  @autoreleasepool {
    return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
  }
}

我想我之前通过启用僵尸解决了这个问题。当我这样做时，我会在控制台中看到：

2018-07-11 16:56:08.326 [info][tid:main][RCTRootView.m:293] Running application Mapp ({
initialProps =     {
};
rootTag = 11;
})
=================================================================
Main Thread Checker: UI API called on a background thread: -[UIApplication setNetworkActivityIndicatorVisible:]
PID: 34682, TID: 5546845, Thread name: (none), Queue name: com.mixpanel.20e6d2c2b6c431dfecfdfaa100ec0a11.0x7fa94db06940.network, QoS: 0
Backtrace:
4   Mapp                           0x0000000103a31dd9 -[MPNetwork updateNetworkActivityIndicator:] + 121
5   Mapp                           0x0000000103a2ec09 -[MPNetwork flushQueue:endpoint:] + 985
6   Mapp                           0x0000000103a2e7b0 -[MPNetwork flushEventQueue:] + 64
7   Mapp                           0x0000000103a10418 __32-[Mixpanel flushWithCompletion:]_block_invoke + 312
8   libdispatch.dylib                   0x000000010e3f47ab _dispatch_call_block_and_release + 12
9   libdispatch.dylib                   0x000000010e3f57ec _dispatch_client_callout + 8
10  libdispatch.dylib                   0x000000010e3fdbe5 _dispatch_queue_serial_drain + 1305
11  libdispatch.dylib                   0x000000010e3fe4fa _dispatch_queue_invoke + 328
12  libdispatch.dylib                   0x000000010e3fa344 _dispatch_queue_override_invoke + 726
13  libdispatch.dylib                   0x000000010e40136c _dispatch_root_queue_drain + 664
14  libdispatch.dylib                   0x000000010e401076 _dispatch_worker_thread3 + 132
15  libsystem_pthread.dylib             0x000000010e920169 _pthread_wqthread + 1387
16  libsystem_pthread.dylib             0x000000010e91fbe9 start_wqthread + 13

这对我来说是不可读的。我不明白出了什么问题。提醒：即使启用了断点，此构建也会在我的设备上运行而不会出现重大错误。这是我应该担心的事情吗？请帮忙！

Answer 1

因为在您的代码中UI API called on a background thread。所以请禁用xcode的Main Thread Checker。它会起作用的。

编辑方案--->诊断--->运行时API检查--->主要 线程检查器（取消选中此设置）

注意：始终在后台线程上更新以下方法中的 UI

或者

把你的[UIApplication setNetworkActivityIndicatorVisible:]方法放在DispatchQueue.main.async里面

    DispatchQueue.main.async { // Correct
        UIApplication.shared.isNetworkActivityIndicatorVisible = true // in swift 4
       [UIApplication setNetworkActivityIndicatorVisible:]// in objective-C
 }

https://developer.apple.com/documentation/code_diagnostics/main_thread_checker