需要包装viewController视图

viewController.m代码全部粘贴即可使用

//

//  ViewController.m

//  练习 刷新数据

//

//  Created by qianfeng on 16/2/24.

//  Copyright © 2016年 mc. All rights reserved.

//  QQ 937496430

#define SCR_W self.view.frame.size.width

#define SCR_H self.view.frame.size.height

#import "ViewController.h"

@interface ViewController () <UITableViewDataSource,UITableViewDelegate>

@property (nonatomic ,strong)UITableView * tableView;

@property (nonatomic,retain)NSMutableArray *dataArray;

@property (nonatomic)NSInteger currentPage; //当前页数

@property (nonatomic)NSInteger refreshState; //0初始状态 //1已经上拉 需要松手 //2正在获取数据状态

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

[self loadData];

[self createTable];

}

- (void)loadData

{

if(_dataArray == nil)

{

_dataArray = [[NSMutableArray alloc] init];

}

for (int index = 0; index < 20; index++) {

NSString *str = [NSString stringWithFormat:@"第%ld页第%d个Cell",_currentPage,index];

[_dataArray addObject:str];

}

_currentPage++;

dispatch_async(dispatch_get_main_queue(), ^{

[_tableView reloadData];

_refreshState = 0;

[self updateRefreshView];

});

}

- (void)createTable

{

_tableView = [[UITableView alloc]initWithFrame:CGRectMake(0, 0, SCR_W, SCR_H)];

[self.view addSubview:_tableView];

_tableView.tableFooterView = [self createFooterView];

self.tableView.delegate = self;

self.tableView.dataSource = self;

}

// 创建footer视图  返回UIView

- (UIView*)createFooterView

{

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 40)];

[view setBackgroundColor:[UIColor whiteColor]];

UILabel *lable = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 40)];

[lable setTextAlignment:NSTextAlignmentCenter];

[lable setText:@"上拉刷新"];

[lable setTextColor:[UIColor darkGrayColor]];

lable.tag = 100;

[view addSubview:lable];

return view;

}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

{

return 50;

}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

return _dataArray.count;

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CELL_ID"];

if(cell == nil){

cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"CELL_ID"];

}

cell.backgroundColor = [UIColor grayColor];

cell.textLabel.text =  _dataArray[indexPath.row];

return cell;

}

//刷新数据

- (void)updateRefreshView

{

UIView *refreshV = _tableView.tableFooterView;

UILabel *titleL = (UILabel*)[refreshV viewWithTag:100];

if(_refreshState == 0)

{

[titleL setText:@"上拉刷新数据"];

}else if(_refreshState == 1){

[titleL setText:@"松手即刷新数据"];

}else if(_refreshState == 2){

[titleL setText:@"正在下载数据..."];

}

}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView

{

if ((_refreshState == 0)&&(scrollView.contentOffset.y + _tableView.frame.size.height > scrollView.contentSize.height + 50)) {

//scrollView.contentSize.height 加 50 是为了防止滑动过快 导致刷新

_refreshState = 1;

[self updateRefreshView];

}

}

//滚动视图已经结束拖动

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate

{

if(_refreshState == 1)

{

_refreshState = 2;

[self updateRefreshView];

[self performSelector:@selector(loadData) withObject:nil afterDelay:3]; //延迟3秒 为了更直观的显示 _refreshState 的状态

// [self loadData];

}

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end