iOS开发笔记--[__NSArrayI addObjectsFromArray:]: unrecognized selector错误

本文详细解析了在使用Swift语言中,当尝试使用.copy方法拷贝NSMutableArray数组时,为什么会触发__NSArrayI错误,并提供了解决方案。重点在于正确理解NSMutableArray与NSArray的区别以及如何避免此类问题。

今天在操作NSMutableArray数字增加和删除时候出现崩溃,报错[__NSArrayI addObjectsFromArray:]: unrecognized selector。

找了一个小时,发“__NSArrayI”这个提示比较重要。查了一下发现

__NSArrayI is a code-word for an immutable array - that is, a "regular" NSArray which you cannot change.

__NSArrayM is a code-word for a mutable array - that is, NSMutableArray. In NSMutableArray, you can add and remove items.

实际上NSArrayI是NSArray.

NSArrayM才是NSMutableArray.

奇怪,我明明是声明的是NSMutableArray. 怎么突然变成了NSArray.

排查代码才发现,在拷贝数组时候用了 .copy 来拷贝,而NSMutableArray拷贝数组时候需要用 .mutableCopy !!!

假如我桌面上的table文件夹里面有3个json文件,每个json文件的格式都像下面这样 [ { "game_logo" : "https://image.x7sy.com/uploads/game_img/20200811/50108186863124421_thumb.png", "show_name" : "山河", "one_game_info" : "全新传奇不一般的体验,等您来战。-1" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20201216/40904839594914372_thumb.png", "show_name" : "荣耀霸业-官方推荐", "one_game_info" : "正版授权传奇激战手游" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20200606/31951617932332999_thumb.png", "show_name" : "武林争霸", "one_game_info" : "首创双职业自由切换 重温激情 热血PK" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20201229/52262633050212311_thumb.png", "show_name" : "血饮天下", "one_game_info" : "三国神将,单职业,等你来战" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20200917/42720341170133240_thumb.png", "show_name" : "冰雪超变", "one_game_info" : "经典传奇元宝无限爆" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20200618/35415230495480897_thumb.png", "show_name" : "烈焰遮天-火龙超变", "one_game_info" : "独创1秒10刀,刀刀斩杀,百倍爆率" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20201126/59938548377963246_thumb.png", "show_name" : "烈火霸者-GM传奇", "one_game_info" : "全新高爆率单职业传奇!送十万充值红包!" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20201225/97509229445281496_thumb.png", "show_name" : "斗转武林", "one_game_info" : "上线送168充值卡" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20191218/41041557986859633_thumb.png", "show_name" : "王城争霸", "one_game_info" : "王城争霸,给你前所未闻的全新传奇体验" } ] 每个文件都是这样根数据结构是数组,里面是json,3个文件名字为data1,data2,data3,现在我想用o c代码解析这三个文件,并且把解析到的文件存储到一个数组里面,数组的元素是字典,
05-28
1.功能说明: UITableView在实际应用场景中,经常涉及到分页加载数据的情况。比较典型的例子是在tableview的顶部下拉可以重新从接口拉取并刷新第一页的数据,在滑动到底部的时候,使用UIActivityIndicatorView转圈并自动加载下一页的数据;不断下滑会重复此过程,直到所有分页数据加载完成; 2.要求: 1).tableview的头部有下拉加载的动画,可以参考MJRreshHeader 2).tableview的底部应该至少包含三种状态: 全部加载完成 加载数据错误 UIActivityIndicatorView转圈(表示加载中) 3).数据文本在桌面tableview文件夹里面,名字分别为data1,data2,data3,需要自己判断分页加载的情况;通过控制page 为1,2,3来获取不同的分页数据; 用o c代码来完成,另外,初始文件如下 // // Train1ViewController.m // iOS_Training_Demo1 // // Created by smwl on 2021/1/14. // #import "Train1ViewController.h" @interface Train1ViewController () @end @implementation Train1ViewController - (void)viewDidLoad { [super viewDidLoad]; self.view.backgroundColor = [UIColor whiteColor]; [self.navigationController setNavigationBarHidden:YES]; [self makeSubView]; } -(void)makeSubView { UILabel * titleLabel = [[UILabel alloc] init]; titleLabel.text = @"Training TableView"; titleLabel.textColor = [UIColor blackColor]; titleLabel.textAlignment = NSTextAlignmentCenter; titleLabel.font = [UIFont systemFontOfSize:18]; [self.view addSubview:titleLabel]; [titleLabel mas_makeConstraints:^(MASConstraintMaker *make) { make.left.right.mas_equalTo(0); make.height.mas_equalTo(40); make.top.mas_equalTo(88 - 40); }]; } #pragma mark - fetch data -(void)fetchDataWithPage:(NSString *)pageStr { } /* #pragma mark - Navigation // In a storyboard-based application, you will often want to do a little preparation before navigation - (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender { // Get the new view controller using [segue destinationViewController]. // Pass the selected object to the new view controller. } */ @end 3个json内容格式如下 [ { "game_logo" : "https://image.x7sy.com/uploads/game_img/20200811/50108186863124421_thumb.png", "show_name" : "山河", "one_game_info" : "全新传奇不一般的体验,等您来战。-1" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20201216/40904839594914372_thumb.png", "show_name" : "荣耀霸业-官方推荐", "one_game_info" : "正版授权传奇激战手游" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20200606/31951617932332999_thumb.png", "show_name" : "武林争霸", "one_game_info" : "首创双职业自由切换 重温激情 热血PK" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20201229/52262633050212311_thumb.png", "show_name" : "血饮天下", "one_game_info" : "三国神将,单职业,等你来战" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20200917/42720341170133240_thumb.png", "show_name" : "冰雪超变", "one_game_info" : "经典传奇元宝无限爆" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20200618/35415230495480897_thumb.png", "show_name" : "烈焰遮天-火龙超变", "one_game_info" : "独创1秒10刀,刀刀斩杀,百倍爆率" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20201126/59938548377963246_thumb.png", "show_name" : "烈火霸者-GM传奇", "one_game_info" : "全新高爆率单职业传奇!送十万充值红包!" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20201225/97509229445281496_thumb.png", "show_name" : "斗转武林", "one_game_info" : "上线送168充值卡" }, { "game_logo" : "https://image.x7sy.com/uploads/game_img/20191218/41041557986859633_thumb.png", "show_name" : "王城争霸", "one_game_info" : "王城争霸,给你前所未闻的全新传奇体验" } ]
05-28
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