使用json从本地文件传递数据

I am trying to pass data to labels from my JSON file onto a simple ViewController but I don't know where to actually pass that data. Would I be able to just add to my setDataToJson method or would I add the data in my viewDidLoad method?

我试图将数据从我的JSON文件传递到一个简单的ViewController，但我不知道在哪里实际传递该数据。我可以只添加到我的setDataToJson方法，还是可以在viewDidLoad方法中添加数据？

here is my code

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
}

2 个解决方案

#1

The problem is the way you're trying to retrieve your file. In order to do it right, you should find first its path in the bundle. Try something like this:

问题是您尝试检索文件的方式。为了做到正确，你应该首先找到它在捆绑中的路径。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;
}

After doing that and once your view is loaded, you should be able to set your labels by retrieving the json like this:

执行此操作后，加载视图后，您应该能够通过检索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];
}

#2

It should be valueForKey instead.

它应该是valueForKey而不是。

Example:

例：

name.text = [infomation valueForKey:@"AnimalName"];

#1