使用json从本地文件传递数据

Question

我试图将数据从我的JSON文件传递到一个简单的ViewController标签,但我不知道在哪里实际传递该数据.我能够只添加到我的setDataToJson方法中,还是会在我的viewDidLoad方法中添加数据？

这是我的代码

@interface NSDictionary(JSONCategories)
+(NSDictionary*)dictionaryWithContentsOfJSONString:(NSString*)fileLocation;
@end

@implementation NSDictionary(JSONCategories)

+(NSDictionary*)dictionaryWithContentsOfJSONString:(NSString*)fileLocation{
    NSData* data = [NSData dataWithContentsOfFile:fileLocation];
    __autoreleasing NSError* error = nil;
    id result = [NSJSONSerialization JSONObjectWithData:data 
                                                options:kNilOptions error:&error];
    if (error != nil) return nil;
    return result;
}
@end

@implementation ViewController
@synthesize name;

- (void)viewDidLoad
{
    [super viewDidLoad];

}

-(void)setDataToJson{

    NSDictionary *infomation = [NSDictionary dictionaryWithContentsOfJSONString:@"Test.json"];
    name.text = [infomation objectForKey:@"AnimalName"];//does not pass data
}

Answer 1

问题是您尝试检索文件的方式.为了做到正确,你应该首先在捆绑中找到它的路径.尝试这样的事情:

+(NSDictionary*)dictionaryWithContentsOfJSONString:(NSString*)fileLocation{
    NSString *filePath = [[NSBundle mainBundle] pathForResource:[fileLocation stringByDeletingPathExtension] ofType:[fileLocation pathExtension]];
    NSData* data = [NSData dataWithContentsOfFile:filePath];
    __autoreleasing NSError* error = nil;
    id result = [NSJSONSerialization JSONObjectWithData:data 
                                                options:kNilOptions error:&error];
    // Be careful here. You add this as a category to NSDictionary
    // but you get an id back, which means that result
    // might be an NSArray as well!
    if (error != nil) return nil;
    return result;
}

执行此操作后,一旦加载了视图,您就可以通过检索json来设置标签,如下所示:

-(void)setDataToJson{
    NSDictionary *infomation = [NSDictionary dictionaryWithContentsOfJSONString:@"Test.json"];
    self.name.text = [infomation objectForKey:@"AnimalName"];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self setDataToJson];
}