iOS9获取所在城市的接口及解析(简单的NSURLSession使用和新的编码方法使用)

/* 定位当前城市的方法调用 */[self asynGETJSONWithURL:@"http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=js" completion:^(id result) {        NSLog(@"%@", result[@"city"]);    }];

/* 方法实现 */- (void)asynGETJSONWithURL:(NSString *)urlString completion:(void(^)(id result))block {    /* 1.转码 */    NSString *enCodingStr = [urlString stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];    /* 2.创建URL对象 */    NSURL *url = [NSURL URLWithString:enCodingStr];    /* 3.创建请求 */    NSURLRequest *request = [NSURLRequest requestWithURL:url];    /* 4.创建链接接受数据 */    NSURLSessionTask *task = [[NSURLSession sharedSession] dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) {        /* 5.数据解析 */        NSString *temResult = [[NSString alloc] initWithData:data  encoding:NSUTF8StringEncoding];        if (temResult.length == 0) {            return ;        }        temResult = [temResult substringFromIndex:21];        temResult = [temResult substringToIndex:temResult.length - 1];        NSData* xmlData = [temResult dataUsingEncoding:NSUTF8StringEncoding];        id result = [NSJSONSerialization JSONObjectWithData:xmlData options:NSJSONReadingMutableContainers error:&error];        /* 6.通过block将result值返回出去 */        block(result);    }];    [task resume];}