很抱歉再次问这个问题，但我仍然卡住了。
我有一个城市对象试图从天气获取器对象中获取天气
@interface WeatherFetcher : NSObject {
}
@property (nonatomic, strong) NSMutableDictionary *weatherData;
- (void)fetchWeather:(NSString *)cityName;
- (void)handleNetworkErorr:(NSError *)error;
- (void)handleNetworkResponse:(NSData *)myData;
@end
这是我将值分配给weatherData
#import "WeatherFetcher.h"
@implementation WeatherFetcher
- (void)fetchWeather:(NSString *)cityName
{
NSString *urlString = @"http://api.openweathermap.org/data/2.5/weather?q=";
urlString = [urlString stringByAppendingString:cityName];
urlString = [urlString stringByAppendingString:@",Aus"];
NSURL *url = [NSURL URLWithString:urlString];
NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];
[NSURLConnection sendAsynchronousRequest:request
queue:[NSOperationQueue mainQueue]
completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
if (connectionError)
{
[self handleNetworkErorr:connectionError];
}
else
{
[self handleNetworkResponse:data];
}
}];
}
#pragma mark - Private Failure Methods
- (void)handleNetworkErorr:(NSError *)error
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Network Error" message:@"Please try again later" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
[alert show];
}
#pragma mark - Private Success Methods
- (void)handleNetworkResponse:(NSData *)myData
{
//NSMutableDictionary *data = [NSMutableDictionary dictionary];
NSMutableDictionary *data = [[NSMutableDictionary alloc] init];
// now we'll parse our data using NSJSONSerialization
id myJSON = [NSJSONSerialization JSONObjectWithData:myData options:NSJSONReadingMutableContainers error:nil];
// typecast an array and list its contents
NSDictionary *jsonArray = (NSDictionary *)myJSON;
//NSLog([jsonArray description]);
// take a look at all elements in the array
for (id element in jsonArray) {
id key = [element description];
id innerArr = [jsonArray objectForKey:key];
NSDictionary *inner = (NSDictionary *)innerArr;
if ([inner conformsToProtocol:@protocol(NSFastEnumeration)]) {
for(id ele in inner) {
if ([ele conformsToProtocol:@protocol(NSFastEnumeration)]) {
NSDictionary *innerInner = (NSDictionary *)ele;
for(id eleEle in innerInner) {
id innerInnerKey = [eleEle description];
[data setObject:[[inner valueForKey:innerInnerKey] description] forKey:[eleEle description]];
}
}
else {
id innerKey = [ele description];
[data setObject:[[inner valueForKey:innerKey] description] forKey:[ele description]];
}
}
}
else {
[data setObject:[inner description] forKey:[element description]];
}
}
self.weatherData = data;
NSLog([self.weatherData description]) **//there is data**
}
@end
但是，每次我从城市对象中调用它时，我都一无所获。
#import <Foundation/Foundation.h>
#import "WeatherFetcher.h"
@interface City : NSObject {
}
@property (nonatomic, strong) NSString *cityName;
@property (nonatomic, strong) NSString *stateName;
@property (nonatomic, strong) UIImage *cityPicture;
@property (nonatomic, strong) NSString *weather;
@property (nonatomic, strong) NSMutableDictionary *weatherData;
-(NSString *)getWeather;
@end
UI 通过按下按钮调用 getWeather 以获取要在屏幕上显示的字符串值
@implementation City {
}
-(NSString *)getWeather {
//return self.weather;
NSString *info = @"";
WeatherFetcher *weatherFetcher = [[WeatherFetcher alloc] init];
[weatherFetcher fetchWeather:self.cityName];
self.weatherData = [weatherFetcher weatherData];
for (id element in self.weatherData) {
info = [info stringByAppendingString:[element description]];
info = [info stringByAppendingString:@"-->"];
info = [info stringByAppendingString:[self.weatherData valueForKey:[element description]]];
info = [info stringByAppendingString:@"\n"];
}
return info;
}
@end
我在这里做错了什么？
当按下按钮并且我试图在文本区域中显示此字符串时，会调用 city 类中的 getWeather 方法。我对 Objective C 没有太多经验，这是我除 Hello World 应用程序之外的第一个应用程序。
谢谢！