iphoneX 头部与顶部适配的关键代码

//iphonex适配

define kNavMargin (iPhoneX ? (64 + iPhoneXNavChangeH) : 64)

define kTabBarMargin (iPhoneX ? (49 +iPhoneXTabChangeH) : 49)

static const NSInteger iPhoneXNavChangeH = 24;
static const NSInteger iPhoneXTabChangeH = 34;