iOS - 尝试在 NSUserDefaults 中插入非属性列表对象 NSDictionary

Question

在我的应用程序中，我需要在我的 NSUserDefaults 中保存我的自定义 User 对象 NSDictionary。我尝试使用以下代码:

NSDictionary *userObjectDictionary = response[@"user"];
NSLog(@"USER OBJECT:\n%@", userObjectDictionary);
[defaults setObject:userObjectDictionary forKey:@"defaultUserObjectDictionary"];
[defaults synchronize];

此尝试使我的应用程序崩溃并显示以下消息:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Attempt to insert non-property list object {type = immutable dict, count = 10, entries => 0 : status_id = 1 : {contents = "first_name"} = exampleFirstName 3 : id = {value = +2, type = kCFNumberSInt64Type} 4 : {contents = "profile_picture"} = {contents = "http://myDevServer.com/pictures/userName.jpg"} 5 : last_name = exampleLastName 7 : email = {contents = "myEmail@gmail.com"} 8 : {contents = "badge_count"} = {value = +0, type = kCFNumberSInt64Type} 9 : user_name = userName 10 : {contents = "phone_number"} = {contents = "0123456789"} 12 : {contents = "status_updated_at"} = } for key defaultUserObjectDictionary'

这是我的 User 对象字典在我尝试保存之前的样子:

{
    "badge_count" = 0;
    email = "myEmail@gmail.com";
    "first_name" = exampleFirstName;
    id = 2;
    "last_name" = exampleLastName;
    "phone_number" = 0123456789;
    "profile_picture" = "http://myDevServer.com/pictures/userName.jpg";
    "status_id" = "<null>";
    "status_updated_at" = "<null>";
    "user_name" = userName;
}

是否因为我的 User 对象 NSDictionary 中有空值而崩溃？我尝试使用带有空值的虚拟数据的常规 NSDictionary 并且它有效。如果这是问题所在，我该如何绕过它？有时我的 User 对象将具有可为 null 的属性。

Answer 1

您的某些对象或字典中的键具有不支持属性列表序列化的类。请查看此答案以获取详细信息:Property list supported ObjC types

我建议检查对象中的键“profile_picture”——它可能是 NSURL。

如果这没有帮助，您可以使用以下代码来识别不兼容的对象:

for (id key in userObjectDictionary) {
    NSLog(@"key: %@, keyClass: %@, value: %@, valueClass: %@",
          key, NSStringFromClass([key class]),
          userObjectDictionary[key], NSStringFromClass([userObjectDictionary[key] class]));
}