1、 error “_OBJC_CLASS_$_XXXXXXX”, referenced from: objc-class-ref in
解决方案：根据_OBJC_CLASS_$_的XXXXXXX找到对应的类库，添加即可
2、崩溃：Trapped uncaught exception 'NSInternalInconsistencyException', reason: 'Client error attempting to change layout margins of a private view'
原因：iOS13中导航栏 KVC私有属性布局导致的崩溃
修改方案：定义一个 UINavigationBar 子类，重写 layoutSubviews 方法，在此方法里遍历 subviews 获取 _UINavigationBarContentView，使用设置 frame 的方式，让 _UINavigationBarContentView 向两边伸展，从而抵消两边的边距
- (void)layoutSubviews {
[super layoutSubviews];
for (UIView *subview in self.subviews) {
if ([NSStringFromClass([subview class]) containsString:@"_UINavigationBarContentView"]) {
if ([UIDevice currentDevice].systemVersion.floatValue >= 13.0) {
UIEdgeInsets margins = subview.layoutMargins;
subview.frame = CGRectMake(-margins.left, -margins.top, margins.left + margins.right + subview.frame.size.width, margins.top + margins.bottom + subview.frame.size.height);
} else {
subview.layoutMargins = UIEdgeInsetsZero;
}
break;
}
}
}
4、ios13版本中，使用Contacts 框架中的unifiedContact方法更新通讯录报错：
store.unifiedContact(withIdentifier: contactID, keysToFetch: keys)错误提示如下：
Error Domain=CNErrorDomain Code=102 "(null)" UserInfo={CNKeyPaths=(
note
), CNInvalidRecords=(
"<CNContactFetchRequest: 0x28115bb10: predicate=<CNiOSABContactIdentifiersPredicate: 0x280a741c0: kind=-[CNContact predicateForContactsWithIdentifiers:], identifiers=(\n \"78DD9DCD-9BEF-460E-872D-C2EA742A6877\"\n)>, keysToFetch=(\n identifier,\n namePrefix,\n givenName,\n middleName,\n familyName,\n previousFamilyName,\n nameSuffix,\n nickname,\n phoneticGivenName,\n phoneticMiddleName,\n phoneticFamilyName,\n phoneNumbers,\n emailAddresses,\n postalAddresses,\n jobTitle,\n departmentName,\n organizationName,\n note,\n contactType,\n birthday,\n nonGregorianBirthday,\n instantMessageAddresses,\n contactRelations,\n socialProfiles,\n dates,\n \"<CNAggregateKeyDescriptor: 0x281feb500: kind=+[CNContactContentViewController descriptorForRequiredKeys]>\"\n), unifyResults=1, sortOrder=0>"
)}错误原因：unifiedContact方法中使用的keys中包含了CNContactNoteKey 这个key，苹果官方描述说明包含这个key，在ios13版本中需要去申请授权才可以使用
解决方案：去掉keys中的CNContactNoteKey，项目即可正常工作
