Question

我阅读了很多关于此的文档，但我无法理解它是如何工作的。我想将我的应用数据以JSON格式保存在手机光盘上。

我有一个这种类型的对象数组：

@interface ObjectA : NSObject

@property (strong, nonatomic) NSMutableArray* names1;
@property (strong, nonatomic) NSMutableArray* names2;
@property (strong, nonatomic) NSMutableArray* names3;
@property (strong, nonatomic) NSMutableArray* names4;
@property (strong, nonatomic) NSString* nameObjectA;
@property (assign) int number;

通过使用JSONModel，我如何转换＆＃34; NSMutableArray * ObjectA＆＃34;在JSON文件中，之后在应用程序中读取此文件。

感谢。

- (id)initWithJSONDictionary:(NSDictionary *)jsonDictionary {
if(self = [self init]) {
    // Assign all properties with keyed values from the dictionary
    _nameObjectA = [jsonDictionary objectForKey:@"nameAction"];
    _number = [[jsonDictionary objectForKey:@"number"]intValue];

   _actions1 = [jsonDictionary objectForKey:@"Action1"];
    _actions2 = [jsonDictionary objectForKey:@"Action2"];
    _actions3 = [jsonDictionary objectForKey:@"Action3"];
    _actions4 = [jsonDictionary objectForKey:@"Action4"];


}

return self;

}

- (NSArray *)locationsFromJSONFile:(NSURL *)url {
// Create a NSURLRequest with the given URL
NSURLRequest *request = [NSURLRequest requestWithURL:url
                                         cachePolicy:NSURLRequestReloadIgnoringLocalAndRemoteCacheData
                                     timeoutInterval:30.0];

// Get the data
NSURLResponse *response;
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:nil];

// Now create a NSDictionary from the JSON data
NSDictionary *jsonDictionary = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];

// Create a new array to hold the locations
NSMutableArray *actions = [[NSMutableArray alloc] init];

// Get an array of dictionaries with the key "actions"
NSArray *array = [jsonDictionary objectForKey:@"actions"];
// Iterate through the array of dictionaries
for(NSDictionary *dict in array) {
    // Create a new Location object for each one and initialise it with information in the dictionary
    Action *action = [[Action alloc] initWithJSONDictionary:dict];
    // Add the Location object to the array
    [actions addObject:action];
}

// Return the array of actions objects
return actions;

}

Answer 1

JSONModel附带的演示应用程序包含一个如何通过JSONMOdel存储应用程序数据的示例：https://github.com/icanzilb/JSONModel

检查此视图控制器中的代码：https://github.com/icanzilb/JSONModel/blob/master/JSONModelDemo_iOS/StorageViewController.m

逻辑是您可以将模型导出到json字符串或json兼容字典，然后使用标准API将它们保存到光盘。检查代码

Answer 2

在ObjectA中，您定义了两个方法 - toDictionary和initWithDictionary。大致是：

-(NSDictionary*) toDictionary {
    return @{@"names1":names1, @"names2":names2, @"names3":names3, @"names4":names4, @"nameObjectA":nameObjectA, @"number":@(number)};
}

- (id) initWithDictionary:(NSDictionary*) json {
    self = [super init];
    if (self) {
        self.names1 = json[@"names1];
        ... etc
        self.nameObjectA = json[@"nameObjectA"];
        self.number = json[@"number"].intValue;
    }
    return self;
}

运行由toDictionary通过NSJSONSerialization创建的字典以生成NSData并将其写入文件。要读取，请从文件中获取NSData，通过NSJSONSerialization运行，然后使用initWithDictionary。

当然，这假设您的词典内容是＆＃34; JSON合法＆＃34; - 字符串，数字，NSArrays或其他NSDictionarys。

并且，如果正在初始化的数组/字典是可变的，那么应该指定＆＃34; MutableContainers＆＃34; NSJSONSerialization上的选项。

使用JSONModel（IOS）保存光盘上的对象数组

2 个答案: