iOS下拉、上拉刷新控件的封装

#import <UIKit/UIKit.h> @interface ViewController : UIViewController @end /*** ---------------分割线--------------- ***/ #import "ViewController.h"#import "HWRefresh.h" @interface ViewController ()<UITableViewDataSource, UITableViewDelegate> @property (nonatomic, strong) NSMutableArray *array;@property (nonatomic, strong) UITableView *tableView;@property (nonatomic, assign) NSInteger page; @end @implementation ViewController - (NSMutableArray *)array{ if (!_array) {  _array = [NSMutableArray array]; }  return _array;} - (void)viewDidLoad { [super viewDidLoad];  self.view.backgroundColor = [UIColor blackColor]; self.page = 1;  //模拟获取信息 [self getInfo];  //创建控件 [self creatControl];  //添加头部刷新 [self addHeaderRefresh];  //添加尾部刷新 [self addFooterRefresh];} - (void)getInfo{ NSArray *array = @[@"iOS HERO博客", @"iOS HERO博客", @"iOS HERO博客", @"iOS HERO博客", @"http://blog.csdn.net/hero_wqb"]; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0f * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{  if (self.page == 1) {   self.array = [NSMutableArray arrayWithArray:array];  }else{   [self.array addObjectsFromArray:array];  }  [_tableView reloadData];  [_tableView headerEndRefreshing];  [_tableView footerEndRefreshing];  NSLog(@"已经刷新好了"); });} - (void)creatControl{ //列表视图 _tableView = [[UITableView alloc] initWithFrame:CGRectMake(20, 64, [[UIScreen mainScreen] bounds].size.width - 100, [[UIScreen mainScreen] bounds].size.height - 164) style:UITableViewStylePlain]; _tableView.dataSource = self; _tableView.delegate = self; [self.view addSubview:_tableView];} - (void)addHeaderRefresh{ __weak typeof(self) weakSelf = self; [_tableView addHeaderRefreshWithCallback:^{  __strong typeof(weakSelf) strongSelf = weakSelf;  strongSelf.page = 1;  [strongSelf getInfo]; }];} - (void)addFooterRefresh{ __weak typeof(self) weakSelf = self; [_tableView addFooterRefreshWithCallback:^{  __strong typeof(weakSelf) strongSelf = weakSelf;  strongSelf.page ++;  [strongSelf getInfo]; }];} #pragma mark - UITableViewDataSource- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{ return self.array.count;} - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{ static NSString *identifier = @"refreshTest"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identifier]; if (!cell) {  cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identifier]; } cell.textLabel.text = [_array[indexPath.row] stringByAppendingString:[NSString stringWithFormat:@"_%ld", indexPath.row]];  return cell;} - (void)scrollViewDidScroll:(UIScrollView *)scrollView{ //滑动到底部自动刷新 if (_tableView.contentSize.height > _tableView.frame.size.height && _tableView.contentOffset.y + _tableView.frame.size.height > _tableView.contentSize.height - 40 && _page < 50) {  [_tableView footerBeginRefreshing]; }} @end

#import <UIKit/UIKit.h> #define HWRefreshContentOffset @"contentOffset" typedef enum { HWRefreshStateNormal = 0, //普通状态 HWRefreshStatePulling,  //释放即可刷新的状态 HWRefreshStateRefreshing, //正在刷新中的状态} HWRefreshState; @interface HWRefreshBaseView : UIView @property (nonatomic, weak) UIScrollView *scrollView;@property (nonatomic, copy) NSString *pullToRefreshText;@property (nonatomic, copy) NSString *releaseToRefreshText;@property (nonatomic, copy) NSString *refreshingText;@property (nonatomic, copy) void (^refreshingCallback)();@property (nonatomic, assign) HWRefreshState state;@property (nonatomic, assign) UIEdgeInsets scrollViewOriginalInset; - (void)beginRefreshing;- (void)endRefreshing; @end /*** ---------------分割线--------------- ***/ #import "HWRefreshBaseView.h" #define KHWRefreshViewHeight 44.0f#define KImageW 30.0f#define KLabelW 100.0f @interface HWRefreshBaseView () @property (nonatomic, weak) UILabel *rLabel;@property (nonatomic, weak) UIImageView *rImageView; @end @implementation HWRefreshBaseView - (instancetype)initWithFrame:(CGRect)frame{ frame.size.height = KHWRefreshViewHeight; if (self = [super initWithFrame:frame]) {  CGFloat imageH = 30.f;  CGFloat labelH = 20.f;  CGFloat imageX = ([UIScreen mainScreen].bounds.size.width - KImageW - KLabelW) * 0.5;  CGFloat imageY = (KHWRefreshViewHeight - imageH) * 0.5;  CGFloat labelY = (KHWRefreshViewHeight - labelH) * 0.5;    //图片  UIImageView *rImageView = [[UIImageView alloc] initWithFrame:CGRectMake(imageX, imageY, KImageW, imageH)];  rImageView.image = [UIImage imageNamed:@"refreshing.jpg"];  [self addSubview:rImageView];  self.rImageView = rImageView;    //标签  UILabel *rLabel = [[UILabel alloc] initWithFrame:CGRectMake(CGRectGetMaxX(rImageView.frame), labelY, KLabelW, labelH)];  rLabel.text = self.pullToRefreshText;  rLabel.font = [UIFont systemFontOfSize:14.0f];  rLabel.textAlignment = NSTextAlignmentCenter;  [self addSubview:rLabel];  self.rLabel = rLabel; }  return self;} - (void)willMoveToSuperview:(UIView *)newSuperview{ [super willMoveToSuperview:newSuperview];  //旧的父控件 [self.superview removeObserver:self forKeyPath:HWRefreshContentOffset context:nil];  //新的父控件 if (newSuperview) {  [newSuperview addObserver:self forKeyPath:HWRefreshContentOffset options:NSKeyValueObservingOptionNew context:nil];    //记录UIScrollView  _scrollView = (UIScrollView *)newSuperview;    //记录UIScrollView最开始的contentInset  _scrollViewOriginalInset = _scrollView.contentInset; }  //居中显示图片、提示信息 CGRect temFrame = _rImageView.frame; temFrame.origin.x = (newSuperview.frame.size.width - KImageW - KLabelW) * 0.5; _rImageView.frame = temFrame;  CGRect tf = _rLabel.frame; tf.origin.x = CGRectGetMaxX(_rImageView.frame); _rLabel.frame = tf;} - (void)setPullToRefreshText:(NSString *)pullToRefreshText{ _pullToRefreshText = pullToRefreshText;  self.rLabel.text = pullToRefreshText;} - (void)setState:(HWRefreshState)state{ if (_state == state) return;  switch (state) {  case HWRefreshStateNormal: {   [self stopAnimating];   self.rLabel.text = self.pullToRefreshText;   break;  }     case HWRefreshStatePulling: {   self.rLabel.text = self.releaseToRefreshText;   break;  }     case HWRefreshStateRefreshing: {   [self startAnimating];   self.rLabel.text = self.refreshingText;   if (self.refreshingCallback) self.refreshingCallback();   break;  }     default:   break; }  _state = state;} //开始刷新- (void)beginRefreshing{ self.state = HWRefreshStateRefreshing;} //结束刷新- (void)endRefreshing{ self.state = HWRefreshStateNormal;} //开始动画- (void)startAnimating{ NSMutableArray *array = [NSMutableArray array]; for (int i = 0; i < 2; i++) {  NSString *imageName = [NSString stringWithFormat:@"refreshing%02d.jpg", i + 1];  UIImage *image = [UIImage imageNamed:imageName];  [array addObject:image]; }  [_rImageView setAnimationImages:array]; [_rImageView setAnimationDuration:0.3f]; [_rImageView startAnimating];} //结束动画- (void)stopAnimating{ if (_rImageView.isAnimating) {  [_rImageView stopAnimating];  [_rImageView performSelector:@selector(setAnimationImages:) withObject:nil afterDelay:0]; }} @end

#import "HWRefreshBaseView.h" @interface HWRefreshHeader : HWRefreshBaseView + (instancetype)header; @end /*** ---------------分割线--------------- ***/ #import "HWRefreshHeader.h" @implementation HWRefreshHeader + (instancetype)header{ return [[HWRefreshHeader alloc] init];} - (instancetype)initWithFrame:(CGRect)frame{ if (self = [super initWithFrame:frame]) {  self.pullToRefreshText = @"下拉即可刷新";  self.releaseToRefreshText = @"释放即可刷新";  self.refreshingText = @"刷新中..."; }  return self;} - (void)willMoveToSuperview:(UIView *)newSuperview{ [super willMoveToSuperview:newSuperview];  //设置自己的位置和尺寸 CGRect frame = self.frame; frame.origin.y = - self.frame.size.height; self.frame = frame;}  - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context{ //不能跟用户交互或正在刷新就直接返回 if (!self.userInteractionEnabled || self.alpha <= 0.01 || self.hidden || self.state == HWRefreshStateRefreshing) return;  //根据偏移量设置相应状态 if ([keyPath isEqualToString:HWRefreshContentOffset]) {  [self setStateWithContentOffset]; }} - (void)setStateWithContentOffset{ //当前的contentOffset CGFloat currentOffsetY = self.scrollView.contentOffset.y;  //头部控件刚好出现的offsetY CGFloat happenOffsetY = - self.scrollViewOriginalInset.top;  //如果是向上滚动到看不见头部控件，直接返回 if (currentOffsetY >= happenOffsetY) return;  //滑动时 if (self.scrollView.isDragging) {  //普通状态和即将刷新状态的临界点  CGFloat normalTopullingOffsetY = happenOffsetY - self.frame.size.height;    //转为即将刷新状态  if (self.state == HWRefreshStateNormal && currentOffsetY < normalTopullingOffsetY) {   self.state = HWRefreshStatePulling;     //转为普通状态  }else if (self.state == HWRefreshStatePulling && currentOffsetY >= normalTopullingOffsetY) {   self.state = HWRefreshStateNormal;  }   //松手时，如果是松开就可以进行刷新的状态，则进行刷新 }else if (self.state == HWRefreshStatePulling) {  self.state = HWRefreshStateRefreshing; }} - (void)setState:(HWRefreshState)state{ //若状态未改变，直接返回 if (self.state == state) return;  //保存旧状态 HWRefreshState oldState = self.state;  //调用父类方法 [super setState:state];  switch (state) {  case HWRefreshStateNormal: {   //如果由刷新状态返回到普通状态   if (oldState == HWRefreshStateRefreshing) {    [UIView animateWithDuration:0.25f animations:^{     UIEdgeInsets inset = self.scrollView.contentInset;     inset.top -= self.frame.size.height;     self.scrollView.contentInset = inset;    }];   }   break;  }     case HWRefreshStatePulling: {   break;  }     case HWRefreshStateRefreshing: {   //执行动画   [UIView animateWithDuration:0.25f animations:^{    CGFloat top = self.scrollViewOriginalInset.top + self.frame.size.height;        //增加滚动区域    UIEdgeInsets inset = self.scrollView.contentInset;    inset.top = top;    self.scrollView.contentInset = inset;        //设置滚动位置    CGPoint offset = self.scrollView.contentOffset;    offset.y = - top;    self.scrollView.contentOffset = offset;   }];   break;  }     default:   break; }  self.state = state;} @end

#import <UIKit/UIKit.h> @interface UIScrollView (HWRefresh) //添加下拉刷新回调- (void)addHeaderRefreshWithCallback:(void (^)())callback; //让下拉刷新控件停止刷新- (void)headerEndRefreshing; //添加上拉刷新回调- (void)addFooterRefreshWithCallback:(void (^)())callback; //让上拉刷新控件开始刷新- (void)footerBeginRefreshing; //让上拉刷新控件停止刷新- (void)footerEndRefreshing; @end /*** ---------------分割线--------------- ***/ #import "UIScrollView+HWRefresh.h"#import "HWRefreshHeader.h"#import "HWRefreshFooter.h"#import <objc/runtime.h> @interface UIScrollView () @property (nonatomic, weak) HWRefreshHeader *header;@property (weak, nonatomic) HWRefreshFooter *footer; @end @implementation UIScrollView (HWRefresh) static char HWRefreshHeaderKey;static char HWRefreshFooterKey; - (void)setHeader:(HWRefreshHeader *)header{ [self willChangeValueForKey:@"HWRefreshHeaderKey"]; objc_setAssociatedObject(self, &HWRefreshHeaderKey, header, OBJC_ASSOCIATION_ASSIGN); [self didChangeValueForKey:@"HWRefreshHeaderKey"];} - (HWRefreshHeader *)header{ return objc_getAssociatedObject(self, &HWRefreshHeaderKey);} - (void)setFooter:(HWRefreshFooter *)footer{ [self willChangeValueForKey:@"HWRefreshFooterKey"]; objc_setAssociatedObject(self, &HWRefreshFooterKey, footer, OBJC_ASSOCIATION_ASSIGN); [self didChangeValueForKey:@"HWRefreshFooterKey"];} - (HWRefreshFooter *)footer{ return objc_getAssociatedObject(self, &HWRefreshFooterKey);} - (void)addHeaderRefreshWithCallback:(void (^)())callback{ if (!self.header) {  HWRefreshHeader *header = [HWRefreshHeader header];  [self addSubview:header];  self.header = header; }  self.header.refreshingCallback = callback;} - (void)headerEndRefreshing{ [self.header endRefreshing];} - (void)addFooterRefreshWithCallback:(void (^)())callback{ if (!self.footer) {  HWRefreshFooter *footer = [HWRefreshFooter footer];  [self addSubview:footer];  self.footer = footer; }  self.footer.refreshingCallback = callback;} - (void)footerBeginRefreshing{ [self.footer beginRefreshing];} - (void)footerEndRefreshing{ [self.footer endRefreshing];} @end