Objective-C cocoa 应用程序覆盖 JSON 文件

Question

如何使用其他 json 文件的值覆盖 json 文件？我使用 2 个 json 文件来存储应用程序配置的数据，一个是应用程序的默认值，另一个是用户给出的自定义配置值，它将始终运行从自定义文件中检索数据，所以如果用户想要恢复原始配置，它会采用默认文件的值并覆盖自定义文件，这就是逻辑，但我仍在尝试弄清楚如何覆盖文件。

这是我试图在代码中执行的操作，但仍然没有编写任何内容:

@implementation AppDelegate

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    NSString *filePath = [[NSBundle mainBundle] pathForResource:@"custom" ofType:@"json"];
    // Retrieve local JSON file called custom.json
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSError *error = nil; // This so that we can access the error if something goes wrong
    NSData *JSONData = [NSData dataWithContentsOfFile:filePath options:NSDataReadingMappedIfSafe error:&error];
    // Load the file into an NSData object called JSONData

    NSDictionary *lista = [NSJSONSerialization JSONObjectWithData:JSONData options:0 error:nil];

    NSNumber * test = [lista objectForKey:@"tempoTrabalho1"];
    NSInteger teste = [test integerValue];

    NSLog(@"%ld",(long)teste);

    //file to copy from
    NSString *json = [ [NSBundle mainBundle] pathForResource:@"example" ofType:@"json"];
    NSData *jsonData = [NSData dataWithContentsOfFile:json options:kNilOptions error:nil];

    //write file to device
    [jsonData writeToFile:filePath atomically:YES];
}

@end

我想用 example.json 覆盖 custom.json:

示例.json:

{
    "tempoTrabalho1": 25,
    "tempoTrabalho2": 25,
    "tempoTrabalho3": 25,
    "tempoTrabalho4": 25,
    "tempoDescanso1": 5,
    "tempoDescanso2": 5,
    "tempoDescanso3": 5,
    "tempoDescanso4": 20
}

自定义.json:

{
    "tempoTrabalho1": 30,
    "tempoTrabalho2": 30,
    "tempoTrabalho3": 30,
    "tempoTrabalho4": 30,
    "tempoDescanso1": 10,
    "tempoDescanso2": 10,
    "tempoDescanso3": 10,
    "tempoDescanso4": 30
}

Answer 1

[NSData writeToFile:atomically:]方法将默认覆盖(您必须使用接受选项并指定 NSDataWritingWithoutOverwriting 的方法版本，以便不覆盖)。