iOS 异步请求网络数据，传值问题

最新推荐文章于 2020-12-30 11:57:24 发布

夜堂萤火

最新推荐文章于 2020-12-30 11:57:24 发布

阅读量1k

点赞数

本文链接：https://blog.youkuaiyun.com/liuya000/article/details/48295871

版权

本文探讨了使用AFNetworking库进行网络请求的正确实践。对比了直接返回数组与使用回调方式处理请求结果的区别，并指出了直接返回数组可能导致的程序崩溃问题。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

记录学习中遇到的问题

出问题的写法，定义方法请求网络数据，直接在调用方法的页面用数组接收返回的数组。偶尔会出现程序崩溃情况

-(NSMutableArray *)requestAllDataWithListId:(NSString *)listId{
    NSMutableArray *resultArray = [NSMutableArray array];

    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    manager.responseSerializer = [AFHTTPResponseSerializer serializer];
    NSString *urlStr = [NSString stringWithFormat:kLOLMoviesWithAuthor, listId];
    [manager GET:urlStr parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {

        NSString *html = operation.responseString;
        NSData* data=[html dataUsingEncoding:NSUTF8StringEncoding];
        id dict=[NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
        NSArray *array = dict[@"videos"];
        for (NSDictionary *dic in array) {
            LOLSomeOneProgramListModel *model = [[LOLSomeOneProgramListModel alloc] init];
            [model setValuesForKeysWithDictionary:dic];
            [resultArray addObject:model];
        }
        dispatch_async(dispatch_get_main_queue(), ^{
            self.result();
        });

    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {

    }];

    return resultArray;

}

导致程序崩溃的原因是，上面返回的数组是在block体中数据不确定有没有请求下来的情况下执行的，

正确写法，在请求完数据后通过block体回调把要返回的值作为参数传出去

-(void) requestAllDataWithListId:(NSString *)listId{
    NSMutableArray *resultArray = [NSMutableArray array];

    AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
    manager.responseSerializer = [AFHTTPResponseSerializer serializer];
    NSString *urlStr = [NSString stringWithFormat:kLOLMoviesWithAuthor, listId];
    [manager GET:urlStr parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) {

        NSString *html = operation.responseString;
        NSData* data=[html dataUsingEncoding:NSUTF8StringEncoding];
        id dict=[NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
        NSArray *array = dict[@"videos"];
        for (NSDictionary *dic in array) {
            LOLSomeOneProgramListModel *model = [[LOLSomeOneProgramListModel alloc] init];
            [model setValuesForKeysWithDictionary:dic];
            [resultArray addObject:model];
        }
        dispatch_async(dispatch_get_main_queue(), ^{
            self.result(resultArray);
        });

    } failure:^(AFHTTPRequestOperation *operation, NSError *error) {

    }];


}