iOS 12适配以及问题小记

+ (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 = @"无网络"; for (UIView *view in three) {  //alert: iOS12.0 情况下identifier的变成了类"_UIStatusBarIdentifier"而不是NSString，所以会在调用“isEqualToString”方法时发生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: 这个问题和上边一样itemId是_UIStatusBarIdentifier 类型，不是string   NSString *itemId = [[item valueForKeyPath:@"identifier"] description];   if ([itemId isEqualToString:@"_UIStatusBarWifiItem"]) {    state = @"WIFI";   }   state = @"不确定";  } else if ([identifier isEqualToString:@"_UIStatusBarCellularItem.typeDisplayIdentifier"]) {   UIView *statusBarStringView = [view valueForKeyPath:@"_view"];   // 4G/3G/E   state = [statusBarStringView valueForKeyPath:@"text"];  } } return state;}