+ (NSString *)getIphoneXNetWorkStates { 
 UIApplication *app = [UIApplication sharedApplication];
 id statusBar = [[app valueForKeyPath:@"statusBar"] valueForKeyPath:@"statusBar"];
 id one = [statusBar valueForKeyPath:@"regions"];
 id two = [one valueForKeyPath:@"trailing"];
 NSArray *three = [two valueForKeyPath:@"displayItems"];
 NSString *state = @"無網絡";
 for (UIView *view in three) {
  //alert: iOS12.0 情況下identifier的變成了類"_UIStatusBarIdentifier"而不是NSString，所以會在調用“isEqualToString”方法時發(fā)生crash，
  //修改前
//  NSString *identifier = [view valueForKeyPath:@"identifier"];
  //修改后
  NSString *identifier = [[view valueForKeyPath:@"identifier"] description];
  if ([identifier isEqualToString:@"_UIStatusBarWifiItem.signalStrengthDisplayIdentifier"]) {
   id item = [view valueForKeyPath:@"_item"];

   //alert: 這個問題和上邊一樣itemId是_UIStatusBarIdentifier 類型，不是string
   NSString *itemId = [[item valueForKeyPath:@"identifier"] description];
   if ([itemId isEqualToString:@"_UIStatusBarWifiItem"]) {
    state = @"WIFI";
   }
   state = @"不確定";

  } else if ([identifier isEqualToString:@"_UIStatusBarCellularItem.typeDisplayIdentifier"]) {
   UIView *statusBarStringView = [view valueForKeyPath:@"_view"];
   // 4G/3G/E
   state = [statusBarStringView valueForKeyPath:@"text"];
  }

 }
 return state;
}