iOS分页-PageTableView

接口部分

@protocol UITableViewPageDelegate <NSObject>

@optional

/*
    下拉调用
 */
-(void)pullDownRefreshInTableView:(UITableView *_Nonnull)tableView;
/*
    上拉调用
 */
-(void)tableView:(UITableView *_Nonnull)tableView pullUpWithPage:(long)page;


@end


@interface PageTableView : UITableView


@property (nonatomic, weak) id<UITableViewPageDelegate> pageDelegate;

#pragma mark - 数据处理
/*
    allData，分页请求的完整数据
 */
@property(nonatomic, strong, readonly) NSArray<id> *allData;
/*
    添加页面数据
 */
-(void)addCurrentPageData:(NSArray<id> *)currentPageData;
/*
    用于判断是否最后一页
 */
-(void)upgradeCurrentPageCount:(long)currentPageCount;

#pragma mark - 下拉刷新
/*
    赋值给mj_header即可使用
 */
@property(nonatomic, strong, readonly) MJRefreshNormalHeader *normalHeader;

/*
    下拉刷新结束需要调用
 */
-(void)endPullDownRefresh;


#pragma mark - 上拉刷新
/*
    赋值给mj_footer即可使用
 */
@property(nonatomic, strong, readonly) MJRefreshAutoNormalFooter *normalFooter;

/*
    是否允许上拉
    默认不允许，为了良好的用户体验，第一页数据加载出来之前不能进行上拉，当从第二页开始的时候，会自动置为允许
 */
@property(nonatomic, assign) bool allowPullUp;

/*
    currentPage代表当前即将要请求的页，即还未请求
 */
@property(nonatomic, assign, readonly) long currentPage;
@property(nonatomic, assign, readonly) bool lastPage;

/*
    设置pageSize可帮助判断lastPage，与totalCount配合使用
 */
@property(nonatomic, assign) long pageSize;
/*
    支持设置两种总数判断，任选其一
 */
@property(nonatomic, assign) long totalPage;
@property(nonatomic, assign) long totalCount;

/*
    上拉加载结束需要调用
 */
-(void)endPullUpRefresh;

/*
    该操作会迭代下一页
 */
-(void)goNextPage;

/*
    重置上拉刷新，同时会重置currentPage为1
 */
-(void)resetPullUpRefresh;


@end

实现部分

@interface PageTableView ()

@property(nonatomic, strong) NSMutableArray<id> *mutableArray;

@property(nonatomic, assign) long currentPageCount;

@end

@implementation PageTableView
{
    long _currentPage;
    MJRefreshNormalHeader *_normalHeader;
    MJRefreshAutoNormalFooter *_normalFooter;
}

- (instancetype)initWithFrame:(CGRect)frame style:(UITableViewStyle)style
{
    self = [super initWithFrame:frame style:style];
    if (self) {
        _currentPage = 1;
        self.currentPageCount = -1;
        self.pageSize = 0;
        self.totalPage = -1;
        self.totalCount = -1;
        self.allowPullUp = NO;
    }
    return self;
}

#pragma mark - 懒加载/setter/getter
- (MJRefreshNormalHeader *)normalHeader
{
    if (_normalHeader == nil) {
        _normalHeader = [MJRefreshNormalHeader headerWithRefreshingTarget:self refreshingAction:@selector(tableViewPullDownAction)];
        [_normalHeader setTitle:@"下拉进行更新" forState:MJRefreshStateIdle];
        [_normalHeader setTitle:@"松开立即更新" forState:MJRefreshStatePulling];
        [_normalHeader setTitle:@"更新中" forState:MJRefreshStateRefreshing];
        _normalHeader.lastUpdatedTimeLabel.hidden = YES;
    }
    return _normalHeader;
}
-(MJRefreshAutoNormalFooter *)normalFooter
{
    if (_normalFooter == nil) {
        _normalFooter = [MJRefreshAutoNormalFooter footerWithRefreshingTarget:self refreshingAction:@selector(tableViewPullUpAction)];
        [_normalFooter setTitle:@"上拉加载更多" forState:MJRefreshStateIdle];
        [_normalFooter setTitle:@"加载中" forState:MJRefreshStateRefreshing];
        [_normalFooter setTitle:@"————  没有更多信息了  ————" forState:MJRefreshStateNoMoreData];
        _normalFooter.stateLabel.textColor = [UIColor corlorWithR:200 G:200 B:200];
        
        //默认初始化不显示
        _normalFooter.stateLabel.hidden = YES;
    }
    return _normalFooter;
}
-(NSArray<id> *)allData
{
    return [self.mutableArray copy];
}
-(NSMutableArray<id> *)mutableArray
{
    if (_mutableArray == nil) {
        _mutableArray = [NSMutableArray array];
    }
    return _mutableArray;
}
-(long)currentPage
{
    return _currentPage;
}
-(bool)lastPage
{
    if (self.pageSize > 0 && (self.currentPageCount >= 0 && self.currentPageCount < self.pageSize)) {
        return YES;
    }
    //优先使用已加载数据判断是否最后一页（若已加载数据存在）
    if ((self.totalCount >= 0 && self.mutableArray.count > 0) && self.mutableArray.count >= self.totalCount) {
        return YES;
    }
    long lastLoadPage = self.currentPage - 1;
    if ((self.totalPage >= 0) && lastLoadPage >= self.totalPage) {
        return YES;
    }

    if ((self.totalCount >= 0 && self.pageSize > 0) && lastLoadPage * self.pageSize >= self.totalCount) {
        return YES;
    }

    return NO;
}
-(void)setAllowPullUp:(bool)allowPullUp
{
    _allowPullUp = allowPullUp;
    if (self.mj_footer && [self.mj_footer isKindOfClass:[MJRefreshAutoNormalFooter class]]) {
        MJRefreshAutoNormalFooter *normalFooter = (MJRefreshAutoNormalFooter *)self.mj_footer;
        normalFooter.stateLabel.hidden = !allowPullUp;
    }
}

#pragma mark - 外部方法
-(void)addCurrentPageData:(NSArray<id> *)currentPageData
{
    if (self.currentPage == 1) {
        [self.mutableArray removeAllObjects];
    }
    if (currentPageData.count > 0) {
        [self.mutableArray addObjectsFromArray:currentPageData];
    }
    [self upgradeCurrentPageCount:currentPageData.count];
}
-(void)upgradeCurrentPageCount:(long)currentPageCount
{
    if (currentPageCount >= 0) {
        self.currentPageCount = currentPageCount;
    }
}

-(void)endPullDownRefresh
{
    if (self.mj_header.state == MJRefreshStateRefreshing) {
        [self.mj_header endRefreshing];
    }
}
-(void)endPullUpRefresh
{
    if (self.mj_footer) {
        if (self.lastPage) {
            //最后一页，结束刷新并展示无更多数据
            [self.mj_footer endRefreshingWithNoMoreData];
        }
        else
        {
            //结束刷新
            [self.mj_footer endRefreshing];
        }
    }
}
-(void)goNextPage
{
    _currentPage = _currentPage + 1;
    if (self.currentPage > 1) {
        self.allowPullUp = YES;
    }
}
-(void)resetPullUpRefresh
{
    self.allowPullUp = NO;
    _currentPage = 1;
    self.currentPageCount = -1;
    if (self.mj_footer) {
        self.mj_footer.state = MJRefreshStateIdle;
    }
}

#pragma mark - 内部方法
-(void)tableViewPullDownAction
{
    //下拉刷新需要重置上拉操作
    [self resetPullUpRefresh];
    
    if (self.pageDelegate && [self.delegate respondsToSelector:@selector(pullDownRefreshInTableView:)]) {
        [self.pageDelegate pullDownRefreshInTableView:self];
    }
}
-(void)tableViewPullUpAction
{
    if (self.allowPullUp == NO) {
        //不允许上拉加载更多
        self.mj_footer.state = MJRefreshStateIdle;
        return;
    }
    
    if (self.pageDelegate && [self.delegate respondsToSelector:@selector(tableView:pullUpWithPage:)]) {
        [self.pageDelegate tableView:self pullUpWithPage:self.currentPage];
    }
}


@end