MJRefresh的使用

image

MJRefresh 是一个优秀的下拉刷新组件。
github 地址

//
//  ViewController.m
//  mjtable
//
//  Created by ldhonline on 2018/10/26.
//  Copyright © 2018年 aidoutu.com. All rights reserved.
//

#import "ViewController.h"
#import "Masonry.h"
#import "MJRefresh.h"
#import "MASConstraint+Hidden.h"
#import "UIView+MasonryHidden.h"
#import "Color+Utils.h"

@interface ViewController ()

@end

@implementation ViewController
{
    UITableView *_table;
    NSUInteger count;
    NSArray *data;
}
- (void)viewDidLoad {
    [super viewDidLoad];
    count = 0;
    data = @[];
    _table = [[UITableView alloc] initWithFrame:CGRectMake(0, 64, 400, 400) style:UITableViewStylePlain];
    _table.delegate = self;
    _table.dataSource = self;
    [self.view addSubview:_table];
    
    UIImageView *img = [[UIImageView alloc] init];
    
    img.image = [UIImage imageNamed:@"r"];
    img.contentMode = UIViewContentModeScaleAspectFit;
    
    img.frame = CGRectMake(0,-50, 400, 50);
    
    [_table addSubview:img];
    
    // 加入内部 padding
    _table.contentInset = UIEdgeInsetsMake(50, 0, 0, 0);
    
    
   // [_table reloadData];
    
    
    MJRefreshNormalHeader *header = [MJRefreshNormalHeader headerWithRefreshingBlock:^{
        [self performSelector:@selector(loadTableViewFirstPage) withObject:nil afterDelay:0.5];
    }];
    
    // 当table 上面插入了其它元素时，忽略多少 paddingTop
    header.ignoredScrollViewContentInsetTop = 50;
    
    // auto 模式会自动跟在最后的元素后面
    MJRefreshAutoNormalFooter *footer = [MJRefreshAutoNormalFooter footerWithRefreshingBlock:^{
        [self performSelector:@selector(loadTableViewNextPage) withObject:nil afterDelay:0.5];
    }];
    
    footer.hidden = YES;// 开始是隐藏的
    footer.onlyRefreshPerDrag = YES; // 多次拉取也只加载一次
    footer.triggerAutomaticallyRefreshPercent = -20;// 离 bottom 多远的时候就触发
    [footer setTitle:@"下拉查看更多的评论" forState:MJRefreshStateIdle];
    [footer setTitle:@"正在疯狂加载 ..." forState:MJRefreshStateRefreshing];
    [footer setTitle:@"我也是有底线" forState:MJRefreshStateNoMoreData];
    
    _table.mj_header = header;
    _table.mj_footer = footer;
    
    [self loadTableViewFirstPage];
}

-(void)mj_firstPageDidLoad{
    [_table.mj_header endRefreshing];
    // 只要有数据，就显示加载更多, 没有数据隐藏控件，不能再上拉
    _table.mj_footer.hidden = [data count] == 0;
    // 不足一屏的时候显示没有更多了，也不能上拉
    if([data count] < 5){
        [_table.mj_footer endRefreshingWithNoMoreData];
    }else{
        [_table.mj_footer resetNoMoreData];
    }
    [_table reloadData];
}

-(void)mj_nextPageDidLoad{
    // 加载一页后回到等待上拉状态
    [_table.mj_footer endRefreshing];
    [_table reloadData];
}

-(void)mj_allPageDidLoad{
    // 没有更多数据时，回到不能上拉状态
    [_table.mj_footer endRefreshingWithNoMoreData];
    [_table reloadData];
}

- (void)loadTableViewFirstPage{
    data = [self getArrWithCount:5];
    [self mj_firstPageDidLoad];
}

- (void)loadTableViewNextPage{
    data = [data arrayByAddingObjectsFromArray:[self getArrWithCount:5]];
    if([data count] >= 45){
        [self mj_allPageDidLoad];
    }else{
        [self mj_nextPageDidLoad];
    }
}

- (NSArray *)getArrWithCount:(NSUInteger)count{
    NSMutableArray *ret = [NSMutableArray array];
    for (int i = 0; i < count; i++) {
        [ret addObject: randColor];
    }
    return ret;
}

#pragma mark - UITableViewDataSource

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [data count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [UITableViewCell new];
    cell.textLabel.text = @"ok, is google";
    cell.backgroundColor = data[indexPath.row];
    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    
}

#pragma mark - UITableViewDelegate

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 50;
}


@end