如何将JSON字符串保存到NSUserDefaults？

Question

我有一个JSON请求,返回不同的参数,例如名称.我想为name参数缓存一个变量,稍后我可以在app中查看.

例如:来自JSON request = david的名称.该变量称为firstname.firstname应该等于"david".应该存储名字,以便我可以在我的应用程序的所有部分中查看它.

我看到另一个类似的问题是一个解决方案是:

NSString *valueToSave = @"someValue";
[[NSUserDefaults standardUserDefaults]
    setObject:valueToSave forKey:@"preferenceName"];

并在以后取回它:

NSString *savedValue = [[NSUserDefaults standardUserDefaults]
    stringForKey:@"preferenceName"];

当我解析像这样的JSON文件时,如何使用此方法？:

@implementation Videos

@synthesize tableView = _tableView, activityIndicatorView = _activityIndicatorView, movies = _movies;

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.title = @"Title";
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Menu"
                                                                             style:UIBarButtonItemStylePlain
                                                                            target:(DEMONavigationController *)self.navigationController
                                                                            action:@selector(showMenu)];


    NSString *valueToSave = @"TitleString";
    [[NSUserDefaults standardUserDefaults]
     setObject:valueToSave forKey:@"title"];

    self.tableView.separatorColor = [UIColor clearColor];

    // Setting Up Activity Indicator View
    self.activityIndicatorView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
    self.activityIndicatorView.hidesWhenStopped = YES;
    self.activityIndicatorView.center = self.view.center;
    [self.view addSubview:self.activityIndicatorView];
    [self.activityIndicatorView startAnimating];
    self.tableView.separatorColor = [UIColor clearColor];

    // Initializing Data Source
    self.movies = [[NSArray alloc] init];

    NSURL *url = [[NSURL alloc] initWithString:@"http://link-to-json.php?name=Name"];
    NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];

    AFJSONRequestOperation *operation = [AFJSONRequestOperation JSONRequestOperationWithRequest:request success:^(NSURLRequest *request, NSHTTPURLResponse *response, id JSON) {
        self.movies = JSON;
        [self.activityIndicatorView stopAnimating];
        [self.tableView reloadData];

    } failure:^(NSURLRequest *request, NSHTTPURLResponse *response, NSError *error, id JSON) {
        NSLog(@"Request Failed with Error: %@, %@", error, error.userInfo);
    }];

    [operation start];

}

// Table View Data Source Methods
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    if (self.movies && self.movies.count) {
        return self.movies.count;
    } else {
        return 0;
    }
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 374;
}

- (void)tableView:(UITableView *)tableView
  willDisplayCell:(UITableViewCell *)cell
forRowAtIndexPath:(NSIndexPath *)indexPath
{
    [cell setBackgroundColor:[UIColor clearColor]];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *simpleTableIdentifier = @"VideosObject";

    VideosObject *cell = (VideosObject *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
    if (cell == nil)
    {
        NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"VideosObject" owner:self options:nil];
        cell = [nib objectAtIndex:0];
        cell.selectionStyle = UITableViewCellSelectionStyleNone;

        UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"Purple Sunrise Pattern iPhone 5 Wallpaper.png"]];

        self.tableView.backgroundView = imageView;
    }

    NSDictionary *movie = [self.movies objectAtIndex:indexPath.row];
    cell.title.text = [movie objectForKey:@"title"];

    NSURL *url = [[NSURL alloc] initWithString:[movie objectForKey:@"link"]];
    [cell.pic setImageWithURL:url placeholderImage:[UIImage imageNamed:@"placeholder"]];

    return cell;
}

@end

Answer 1

您可以保存解析JSON后获得的字典:

NSDictionary *result = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&error];

[[NSUserDefaults standardUserDefaults] setObject:result forKey:@"myJSONParsed"];

并把它拿回来:

NSDictionary *myJSON = [[NSUserDefaults standardUserDefaults] objectforKey:@"myJSONParsed"];