ios 使用json从本地文件传递数据
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Passing data from local file using json
提问by domshyra
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 setDataToJsonmethod or would I add the data in my viewDidLoadmethod?
我试图将数据从我的 JSON 文件传递到标签到一个简单的 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方法中，还是可以在我的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
}
回答by Alladinian
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:
问题在于您尝试检索文件的方式。为了正确地做到这一点，您应该首先在包中找到它的路径。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;
}
After doing that and once your view is loaded, you should be able to set your labels by retrieving the json like this:
这样做之后，一旦你的视图被加载，你应该能够通过像这样检索 json 来设置你的标签：
-(void)setDataToJson{
NSDictionary *infomation = [NSDictionary dictionaryWithContentsOfJSONString:@"Test.json"];
self.name.text = [infomation objectForKey:@"AnimalName"];
}
- (void)viewDidLoad
{
[super viewDidLoad];
[self setDataToJson];
}
回答by user523234
It should be valueForKeyinstead.
应该是这样valueForKey。
Example:
例子：
name.text = [infomation valueForKey:@"AnimalName"];
