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引言

需求：由于消息列表，数据量比较大，为了提升用户体验，需采用分页加载显示数据

案例：iOS零售版ERP APP增加支付奖励消息通知

通知信息（定时xx点；历史消息可查）

2021-04-29 尊敬的商家，您参与的xxx激励金活动，昨日参与成功10笔，共获得激励金1元！

I 集成下/上拉刷新控件

1.1 定义相关分页属性

分页属性







@property (nonatomic , assign) NSInteger pageNum;//当前页码
@property (nonatomic , assign) NSInteger pageCount;// 总页数
@property (nonatomic , assign) BOOL isfooterRereshing;
// 每页显示数...

VM中的事件和数据属性

@property (nonatomic,strong)  NSMutableArray *datas;








@property (nonatomic,strong)  RACSubject *reloadSubject;




@property (nonatomic,strong)  RACSubject *ShowNoviewSubject;





@property (nonatomic,strong)  RACSubject *hidenNoviewSubject;

1.2 监听下拉和上拉事件

VC 监听和处理下拉和上拉事件

        _tableView.mj_footer = [MJRefreshBackNormalFooter footerWithRefreshingTarget:self refreshingAction:@selector(footerRereshing)];
        _tableView.mj_header = [MJRefreshNormalHeader headerWithRefreshingTarget:self refreshingAction:@selector(headerRereshing)];

处理上拉加载数据事件

/** 用于标志下拉动作*/
@property (nonatomic , assign) BOOL isfooterRereshing;



- (void)footerRereshing
{
    self.isfooterRereshing = YES;

    if ((_pageNum + 1) >  _pageCount) {
        
        
        

        [self.tableView.mj_footer endRefreshingWithNoMoreData];
        
        return;
        

    }
    

    
    
    _pageNum = _pageNum + 1;
    [self doorRequest];
    

    
    

}

处理下拉刷新数据事件

- (void)headerRereshing
{

    self.isfooterRereshing = NO;





    

    
    
    [_doorArr removeAllObjects];// 移除数据，可请求成功之后，再移除
    _pageNum = 1;
    [self doorRequest];
    
    
}

1.3 请求数据的处理

请求成功和失败都要关闭刷新视图

        [weakSelf.vcView.tableView.mj_footer endRefreshing];
        [weakSelf.vcView.tableView.mj_header endRefreshing];

完成处理的代码

- (void)doorRequest
{

    
    //暂无数据
    

    if (self.viewModel.datas.count == 0) {
        [self.viewModel.ShowNoviewSubject sendNext:QCTLocal(@"no_data")];
        
    }else{
        [self.viewModel.hidenNoviewSubject sendNext:QCTLocal(@"")];
        

    }
    
    if(![UserInfoModel.shareUserInfoModel ispayStoreId]){
        

        //        [self showHUDMessage:@"请先进件"];
        // 显示暂无数据
        
        return;
        
    }
    
    

    NSString *post = [NSString stringWithFormat:@"%@%@",currentPayHost,@""];
    

    
    
    NSMutableDictionary *params = [NSMutableDictionary dictionary];
    //111850
    //    [params setValue:@"" forKey:@"sid"];
    [params setValue:UserInfoModel.shareUserInfoModel.store.payStoreId forKey:@"sid"];
    
    [params setValue:[[NSNumber numberWithInteger:self.pageNum]description] forKey:@"page"];
    
    
    [params setValue:kPageSize forKey:@"pageSize"];
    
    
    
    
    __weak __typeof__(self) weakSelf = self;
    
    [QCTNetworkHelper Post:post parameters:params success:^(NSDictionary* responseObj) {
        
        
        NSDictionary *data = nil;
        
        if([responseObj.allKeys containsObject:@"data"]){
            
            
            
            data = responseObj[@"data"];
            
            
            
            
        }else{
            
            [self showHUDMessage:@"数据异常!"];
            //                    [SVProgressHUD showInfoWithStatus:@"数据异常!"];
            
            return;// 获取数据失败
            
        }
        
        if([data.allKeys containsObject:@"data"]){
            
            
            data = responseObj[@"data"];
            
        }else{
            //                    [SVProgressHUD showInfoWithStatus:@"数据异常!"];
            [self showHUDMessage:@"数据异常!"];
            
            return;// 获取数据失败
            
            
        }
        
        
        NSMutableArray* tmparrresult = [ERPTradeRewardReportDto mj_objectArrayWithKeyValuesArray:data[@"data"]];
        
        if(self.isfooterRereshing){
            
            [weakSelf.viewModel.datas addObjectsFromArray:tmparrresult];
            
        }else{
            
            weakSelf.viewModel.datas  =  tmparrresult ;
            
        }
        
        
        [weakSelf.vcView.tableView reloadData];
        
        
        weakSelf.pageCount = [responseObj[@"data"][@"pageCount"] integerValue];
        weakSelf.pageNum = [responseObj[@"data"][@"page"] integerValue];
        
        
        
        
        
        
        [weakSelf.vcView.tableView.mj_footer endRefreshing];
        [weakSelf.vcView.tableView.mj_header endRefreshing];
        
        
        
        
        if (weakSelf.viewModel.datas.count == 0) {
            [weakSelf.viewModel.ShowNoviewSubject sendNext:QCTLocal(@"no_data")];
            
            
        }else{
            [weakSelf.viewModel.hidenNoviewSubject sendNext:QCTLocal(@"no_data")];
            
        }
        
        
        
    } failure:^(NSError * _Nonnull error) {
        
        [QCTNetworkHelper   showLoading_failed_please_try_again_laterBlock];
        [self.vcView.tableView.mj_footer endRefreshing];
        [self.vcView.tableView.mj_header endRefreshing];
        
    } bizFailure:^(id  _Nonnull responseObj) {
        
        
        [self.vcView.tableView.mj_footer endRefreshing];
        [self.vcView.tableView.mj_header endRefreshing];
        
        
        [QCTNetworkHelper showresponseObjmessage:responseObj];
        
        
        
    }  isShowLoadingDataGif:YES];
    
    
    
    
    
}

II iOS实现无感知上拉加载更多

2.1 思路1:UITableViewDataSourcePrefetching

// this protocol can provide information about cells before they are displayed on screen.





@protocol UITableViewDataSourcePrefetching <NSObject>





@required



// indexPaths are ordered ascending by geometric distance from the table view
- (void)tableView:(UITableView *)tableView prefetchRowsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths;


@optional



// indexPaths that previously were considered as candidates for pre-fetching, but were not actually used; may be a subset of the previous call to -tableView:prefetchRowsAtIndexPaths:
- (void)tableView:(UITableView *)tableView cancelPrefetchingForRowsAtIndexPaths:(NSArray<NSIndexPath *> *)indexPaths;



@end

2.2 实现思路2：通过 KVO 去监听 scrollView 的 contentOffset 变化

MJRefreshAutoFooter 有个专门的属性triggerAutomaticallyRefreshPercent 去做自动刷新

#import "MJRefreshFooter.h"





NS_ASSUME_NONNULL_BEGIN





@interface MJRefreshAutoFooter : MJRefreshFooter
/** 是否自动刷新(默认为YES) */
@property (assign, nonatomic, getter=isAutomaticallyRefresh) BOOL automaticallyRefresh;



/** 当底部控件出现多少时就自动刷新(默认为1.0，也就是底部控件完全出现时，才会自动刷新) */
@property (assign, nonatomic) CGFloat appearencePercentTriggerAutoRefresh MJRefreshDeprecated("请使用triggerAutomaticallyRefreshPercent属性");



/** 当底部控件出现多少时就自动刷新(默认为1.0，也就是底部控件完全出现时，才会自动刷新) */
@property (assign, nonatomic) CGFloat triggerAutomaticallyRefreshPercent;



/** 自动触发次数, 默认为 1, 仅在拖拽 ScrollView 时才生效,
 
 如果为 -1, 则为无限触发
 */
@property (nonatomic) NSInteger autoTriggerTimes;
@end

III 刷新控件的适配

上拉加载：安全区域距离适配

#define k_safeAreaInsetsBottom [UIApplication sharedApplication].delegate.window.safeAreaInsets.bottom





#define isIphoneX isHasSafeAreaInsets





#define k_ignoredScrollViewContentInsetBottom (isIphoneX?k_safeAreaInsetsBottom:0)



        _vcView.tableView.mj_footer.ignoredScrollViewContentInsetBottom = k_ignoredScrollViewContentInsetBottom;

下拉刷新适配：present 半屏适配、设置下拉样式
blog.csdn.net/z929118967/…
分页并发适配：
方式1. 升级MJRefresh到3.7.5版本
Fix/duplicated async method -> Installing MJRefresh 3.7.5 (was 3.3.1)
方式2. 使用自动刷新控件MJRefreshNormalHeader->MJRefreshAutoNormalFooter