swift - 如何解决 myModel 变量中的 UserDefaults 设置错误？

Question

我想使用 UserDefault 设置我的变量，我尝试了很多次，但每次都返回错误。

我错过了什么？

型号

import Foundation

struct MyModel: Codable{
    var one: String?
    var two: String?
}

变量

var savedData: [String : MyModel] {
        get {
            return UserDefaults.standard.object(forKey: "key") as! [String : MyModel]? ?? [String : MyModel]()
        }
        set (newData) {
            UserDefaults.standard.set(newData, forKey: "key")
        }
    }

代码

 self.savedData[position!] = self.myModel

我无法理解这个错误。对于这个错误我需要了解什么？

0   CoreFoundation                      0x00000001022951bb __exceptionPreprocess + 331
    1   libobjc.A.dylib                     0x0000000101240735 objc_exception_throw + 48
    2   CoreFoundation                      0x0000000102295015 +[NSException raise:format:] + 197
    3   CoreFoundation                      0x00000001021acdb8 _CFPrefsValidateValueForKey + 312
    4   CoreFoundation                      0x00000001021ad24c -[CFPrefsSource setValues:forKeys:count:copyValues:removeValuesForKeys:count:from:] + 380
    5   CoreFoundation                      0x00000001021ad5dc -[CFPrefsSource setValues:forKeys:count:copyValues:from:] + 28
    6   CoreFoundation                      0x00000001021ad633 -[CFPrefsSource setValue:forKey:from:] + 67
    7   CoreFoundation                      0x000000010228ba9e __108-[_CFXPreferences(SearchListAdditions) withSearchListForIdentifier:container:cloudConfigurationURL:perform:]_block_invoke + 318
    8   CoreFoundation                      0x000000010228b1ea normalizeQuintuplet + 314
    9   CoreFoundation                      0x000000010228b954 -[_CFXPreferences(SearchListAdditions) withSearchListForIdentifier:container:cloudConfigurationURL:perform:] + 100
    10  CoreFoundation                      0x0000000102267b4b -[_CFXPreferences setValue:forKey:appIdentifier:container:configurationURL:] + 91
    11  CoreFoundation                      0x000000010226bfa5 _CFPreferencesSetAppValueWithContainer + 117
    12  Foundation                          0x0000000100ce3ce1 -[NSUserDefaults(NSUserDefaults) setObject:forKey:] + 55
    13  X                                   0x00000001006e6937 $S13X21ViewViewControllerC9savedDataSDySSAA12MyModelVGvs + 391
    14  X                                   0x00000001006e6982 $S13X21ViewViewControllerC9savedDataSDySSAA12MyModelVGvmytfU_ + 18
    15  X                                   0x00000001006f1b69 $S13X21ViewViewControllerC11getDateData4dateyAA10DateModelV_tFy10Foundation0H0VSg_So13NSURLResponseCSgs5Error_pSgtcfU_ + 2361
    16  X                                   0x00000001006f4e26 $S13X21ViewViewControllerC11getDateData4dateyAA10DateModelV_tFy10Foundation0H0VSg_So13NSURLResponseCSgs5Error_pSgtcfU_TA + 54
    17  X                                   0x00000001006d2dd0 $S10Foundation4DataVSgSo13NSURLResponseCSgs5Error_pSgIegggg_So6NSDataCSgAGSo7NSErrorCSgIeyByyy_TR + 336
    18  CFNetwork                           0x0000000103f15940 __75-[__NSURLSessionLocal taskForClass:request:uploadFile:bodyData:completion:]_block_invoke + 19
    19  CFNetwork                           0x0000000103f2bb0c __49-[__NSCFLocalSessionTask _task_onqueue_didFinish]_block_invoke + 172
    20  Foundation                          0x0000000100cadf9e __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ + 7
    21  Foundation                          0x0000000100cadea5 -[NSBlockOperation main] + 68
    22  Foundation                          0x0000000100caac14 -[__NSOperationInternal _start:] + 689
    23  Foundation                          0x0000000100cb0c4b __NSOQSchedule_f + 227
    24  libdispatch.dylib                   0x0000000104e52595 _dispatch_call_block_and_release + 12
    25  libdispatch.dylib                   0x0000000104e53602 _dispatch_client_callout + 8
    26  libdispatch.dylib                   0x0000000104e5654d _dispatch_continuation_pop + 565
    27  libdispatch.dylib                   0x0000000104e55927 _dispatch_async_redirect_invoke + 859
    28  libdispatch.dylib                   0x0000000104e6400a _dispatch_root_queue_drain + 351
    29  libdispatch.dylib                   0x0000000104e649af _dispatch_worker_thread2 + 130
    30  libsystem_pthread.dylib             0x00000001052436dd _pthread_wqthread + 619
    31  libsystem_pthread.dylib             0x0000000105243405 start_wqthread + 13

Answer 1

仅采用Codable并不能使自定义对象属性列表兼容，例如您必须添加序列化代码

var savedData: [String : MyModel] {
    get {
        guard let data = UserDefaults.standard.data(forKey: "key") else { return [:] }
        return try? JSONDecoder().decode([String:MyModel].self, from: data) ?? [:]
    }
    set (newData) {
        if let data = try? JSONEncoder().encode(newData) {
            UserDefaults.standard.set(data, forKey: "key")
        }
    }
}