学习AFnetworking时遇到数据的获取问题:
在GET函数体内能成功获取到正确数据,而函数外为null,我想应该是异步问题,那么,如何在函数(block)外面获取到正确的数据呢?
http://localhost/json/1.json 的内容如下:
{
"tempMinC": "11",
"tempMinF": "51",
"weatherCode": "113",
"winddirection": "WNW"
}
代码为:
#import "AFHTTPRequestOperationManager.h"
@interface ViewController ()
{
__block NSString *winddirection;
}
@end
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
NSString *url = @"http://localhost/json/1.json";
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager GET:url parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {
winddirection = [(NSDictionary *)responseObject objectForKey:@"winddirection"];
NSLog(@"winddirection is %@",winddirection);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(@"Error...%@",error);
}];
NSLog(@"out of winddirection is %@",winddirection);
}
执行结果为:
2016-02-02 22:03:39.292 1[1042:60b] out of winddirection is (null)
2016-02-02 22:03:39.419 1[1042:60b] winddirection is WNW
如何在NSLog(@"out of winddirection is %@",winddirection);的地方获取到正确的数据呢?