这篇文章说下：MJRefresh和EGOTableViewPullRefresh的使用方法最下面有原理说明，若有不对或者建议请评论指出，先谢谢了：
首先是英文原文和类库下载地址：/emreberge/EGOTableViewPullRefresh
然后创建好自己使用的tableview控件接着：
添加 QuartzCore.framework 到你的工程中。
将 EGOTableViewPullRefresh 拖到你的工程目录下。然后在需要使用的类里写上
下拉是一个刷新的工作，所以需要我们添加的代码无非就是数据刷新的代码。
（1）在.h文件中添加如下代码
[plain]view plain copy@interface...ViewController:UITableViewController<EGORefreshTableHeaderDelegate> { EGORefreshTableHeaderView*refreshTableHeaderView; BOOLreloading; } -(void)reloadTableViewDataSource; -(void)doneLoadingTableViewData;
（2）在- (void)viewDidLoad函数中添加下面的代码。
[plain]view plain copyif(refreshTableHeaderView==nil){ <spanstyle="white-space:pre"></span>EGORefreshTableHeaderView*view=[[EGORefreshTableHeaderViewalloc]initWithFrame:CGRectMake(0.0f,0.0f-self.tableView.bounds.size.height,self.view.frame.size.width,self.tableView.bounds.size.height)]; view.delegate=self; [self.tableViewaddSubview:view]; refreshTableHeaderView=view; [viewrelease]; } //最后一次更新的时间 [refreshTableHeaderViewrefreshLastUpdatedDate];
（3）在对应的.m文件中添加如下方法
[plain]view plain copy#pragmamark- #pragmamarkDataSourceLoading/ReloadingMethods //更新列表数据 -(void)reloadTableViewDataSource{ [NSThreaddetachNewThreadSelector:@selector(updateNewsByPullTable)toTarget:selfwithObject:nil];//异步加载数据，不影tableView动作 reloading=YES; } //调用JSON服务获取数据 -(void)updateNewsByPullTable { NSString*str=@"http://....../getAllNews.aspx"; NSURL*url=[NSURLURLWithString:str]; ASIHTTPRequest*request=[ASIHTTPRequestrequestWithURL:url]; [requeststartSynchronous]; //接收返回数据 NSString*response=[requestresponseString]; NSLog(@"%@",response); self.data=[responseJSONValue]; [self.tableViewreloadData]; } -(void)doneLoadingTableViewData{ //modelshouldcallthiswhenitsdoneloading reloading=NO; [refreshTableHeaderViewegoRefreshScrollViewDataSourceDidFinishedLoading:self.tableView]; } #pragmamark- #pragmamarkUIScrollViewDelegateMethods -(void)scrollViewDidScroll:(UIScrollView*)scrollView{ [refreshTableHeaderViewegoRefreshScrollViewDidScroll:scrollView]; } -(void)scrollViewDidEndDragging:(UIScrollView*)scrollViewwillDecelerate:(BOOL)decelerate{ [refreshTableHeaderViewegoRefreshScrollViewDidEndDragging:scrollView]; } #pragmamark- #pragmamarkEGORefreshTableHeaderDelegateMethods -(void)egoRefreshTableHeaderDidTriggerRefresh:(EGORefreshTableHeaderView*)view{ [selfreloadTableViewDataSource]; [selfperformSelector:@selector(doneLoadingTableViewData)withObject:nilafterDelay:3.0]; } -(BOOL)egoRefreshTableHeaderDataSourceIsLoading:(EGORefreshTableHeaderView*)view{ returnreloading;//shouldreturnifdatasourcemodelisreloading } -(NSDate*)egoRefreshTableHeaderDataSourceLastUpdated:(EGORefreshTableHeaderView*)view{ return[NSDatedate];//shouldreturndatedatasourcewaslastchanged }
4、总结
总的来说，实现这一功能并不复杂，关键在于-(void)reloadTableViewDataSource这一方法。这里我试了一下，读取数据的操作必须是异步的，要不然和tableView下拉再上弹这个动作会有很明显的延迟。再一次感受到了开源类库的强大，感谢这些大神们的无私贡献，让我们这些iOS开发初学者有机会能做出漂亮的应用。
也可以设置一个基类然后其他uitableview继承它：
.h
staticNSString *CELL_ID = @"cell_id";
@class BaseTableView;
@protocol BaseTableViewDelegate <NSObject>
@optional
//下拉事件
- (void)pullDown:(BaseTableView *)tableView;
//上拉事件
- (void)pullUp:(BaseTableView *)tableView;
//选中单元格事件
- (void)didSelectRowAtIndexPath:(BaseTableView *)tabelView indexPath:(NSIndexPath *)indexPath;
@end
typedefvoid(^PullDonwFinish)(void);
typedefvoid(^PullUpFinish)(void);
@interface BaseTableView :UITableView<EGORefreshTableHeaderDelegate,UITableViewDataSource, UITableViewDelegate>
{
EGORefreshTableHeaderView *_refreshHeaderView;
BOOL _reloading;
UIButton *_moreButton;
}
@property(nonatomic,retain) NSMutableArray *data;
//是否显示下拉控件
@property(nonatomic,assign)BOOL refreshHeader;
//是否有更多(下一页)
@property(nonatomic,assign)BOOL isMore;
@property(nonatomic,copy)PullDonwFinish finishBlock;
@property(nonatomic,copy)PullUpFinish pullUpBlock;
//上拉代理对象
@property(nonatomic,assign)id<BaseTableViewDelegate> refreshDelegate;
//自动执行下拉动作
-(void)launchRefreshing;
- (void)reloadTableViewDataSource;
- (void)doneLoadingTableViewData;
@end
#import "BaseTableView.h @implementation BaseTableView
- (id)initWithFrame:(CGRect)frame
{
self = [superinitWithFrame:frame];
if (self) {
// Initialization code
[self_initViews];
}
return self;
}
- (void)awakeFromNib {
[superawakeFromNib];
[self_initViews];
}
- (void)_initViews {
self.backgroundColor =RGB(242, 243, 240);
self.refreshHeader =YES;
self.isMore =YES;
self.delegate =self;
self.dataSource =self;
_moreButton = [UIButtonbuttonWithType:UIButtonTypeCustom];
_moreButton.frame =CGRectMake(0,0, self.width,44);
_moreButton.backgroundColor = [UIColorclearColor];
[_moreButtonsetTitle:@""forState:UIControlStateNormal];
_moreButton.titleLabel.font = [UIFontsystemFontOfSize:12.0f];
[_moreButtonsetTitleColor:[UIColorlightGrayColor] forState:UIControlStateNormal];
[_moreButtonaddTarget:selfaction:@selector(loadMoreAction)forControlEvents:UIControlEventTouchUpInside];
UIActivityIndicatorView *activityView = [[UIActivityIndicatorViewalloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
activityView.frame =CGRectMake(90,10, 20, 20);
[activityViewstopAnimating];
activityView.tag =;
[_moreButtonaddSubview:activityView];
self.tableFooterView =_moreButton;
}
-(void)launchRefreshing
{
if (_reloading) {
_reloading = NO;
[UIViewanimateWithDuration:0.4animations:^{
[selfsetContentOffset:CGPointMake(0, -80)];
}completion:^(BOOL finished) {
if (finished) {
//设置停止拖拽
[_refreshHeaderViewperformSelector:@selector(egoRefreshScrollViewDidEndDragging:)withObject:selfafterDelay:0.2];
}
}];
}else{
//下拉之前还原_refreshHeaderView的state
[_refreshHeaderViewsetState:EGOOPullRefreshNormal];
[UIViewanimateWithDuration:0.4animations:^{
[selfsetContentOffset:CGPointMake(0, -80)];
}completion:^(BOOL finished) {
if (finished) {
[_refreshHeaderViewsetState:EGOOPullRefreshPulling];
//设置停止拖拽
[_refreshHeaderViewperformSelector:@selector(egoRefreshScrollViewDidEndDragging:)withObject:selfafterDelay:0.2];
}
}];
}
}
- (void)setRefreshHeader:(BOOL)refreshHeader {
_refreshHeader = refreshHeader;
if (self.refreshHeader) {
if (_refreshHeaderView ==nil) {
//创建下拉控件
_refreshHeaderView = [[EGORefreshTableHeaderViewalloc] initWithFrame:CGRectMake(0.0f,0.0f - self.bounds.size.height,self.frame.size.width,self.bounds.size.height)];
_refreshHeaderView.delegate =self;
_refreshHeaderView.backgroundColor = [UIColorclearColor];
[_refreshHeaderViewrefreshLastUpdatedDate];
}
[selfaddSubview:_refreshHeaderView];
}else {
if (_refreshHeaderView.superview !=nil) {
[_refreshHeaderViewremoveFromSuperview];
}
}
}
//上拉按钮的点击事件
- (void)loadMoreAction {
if (self.pullUpBlock !=nil) {
self.pullUpBlock();
}
//调用代理对象的协议方法
if ([self.refreshDelegaterespondsToSelector:@selector(pullUp:)]) {
[self.refreshDelegatepullUp:self];
}
[_moreButtonsetTitle:@"正在加载..."forState:UIControlStateNormal];
UIActivityIndicatorView *activityView = (UIActivityIndicatorView *)[_moreButtonviewWithTag:];
[activityViewstartAnimating];
}
- (void)setIsMore:(BOOL)isMore {
_isMore = isMore;
if (self.isMore) {
[_moreButtonsetTitle:@"加载更多数据"forState:UIControlStateNormal];
_moreButton.enabled =YES;
}else {
[_moreButtonsetTitle:@"没有更多数据"forState:UIControlStateNormal];
_moreButton.enabled =NO;
}
UIActivityIndicatorView *activityView = (UIActivityIndicatorView *)[_moreButtonviewWithTag:];
[activityViewstopAnimating];
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[tableView deselectRowAtIndexPath:indexPathanimated:YES];
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return self.data.count;
}
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableViewdequeueReusableCellWithIdentifier:CELL_ID];
if (!cell) {
cell = [[UITableViewCellalloc] initWithStyle:UITableViewCellStyleDefaultreuseIdentifier:CELL_ID];
}
return cell;
}
/*________________________下拉控件相关方法________________________________*/
#pragma mark -
#pragma mark Data Source Loading / Reloading Methods
- (void)reloadTableViewDataSource{
_reloading = YES;
}
//收起下拉刷新
- (void)doneLoadingTableViewData{
_reloading = NO;
[_refreshHeaderViewegoRefreshScrollViewDataSourceDidFinishedLoading:self];
}
#pragma mark -
#pragma mark UIScrollViewDelegate Methods
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
[_refreshHeaderViewegoRefreshScrollViewDidScroll:scrollView];
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
[_refreshHeaderViewegoRefreshScrollViewDidEndDragging:scrollView];
//偏移量.y + tableView.height =内容的高度
//h是上拉超出来的尺寸
float h = scrollView.contentOffset.y + scrollView.height - scrollView.contentSize.height;
if (h > 30 &&self.isMore) {
[selfloadMoreAction];
}
}
#pragma mark -
#pragma mark EGORefreshTableHeaderDelegate Methods
//下拉到一定距离，手指放开时调用
- (void)egoRefreshTableHeaderDidTriggerRefresh:(EGORefreshTableHeaderView*)view{
[selfreloadTableViewDataSource];
//停止加载，弹回下拉
// [self performSelector:@selector(doneLoadingTableViewData)
// withObject:nil afterDelay:3.0];
if (self.finishBlock !=nil) {
self.finishBlock();
}
if ([self.refreshDelegaterespondsToSelector:@selector(pullDown:)]) {
[self.refreshDelegatepullDown:self];
}
}
- (BOOL)egoRefreshTableHeaderDataSourceIsLoading:(EGORefreshTableHeaderView*)view{
return_reloading;// should return if data source model is reloading
}
//取得下拉刷新的时间
- (NSDate *)egoRefreshTableHeaderDataSourceLastUpdated:(EGORefreshTableHeaderView*)view{
return [NSDatedate]; // should return date data source was last changed
}
@end
浅谈下拉刷新和上拉加载更多原理：
下文出自：/hmt0412/article/details/32695305
很多App中,新闻或者展示类都存在下拉刷新和上拉加载的效果,网上提供了实现这种效果的第三方类(详情请见MJRefresh和EGOTableViewPullRefresh),用起来很方便,但是闲暇之余,我们可以思考下,这种效果实现的原理是什么,我以前说过,只要是动画都是骗人的,只要不是硬件问题大部分效果都能在系统UI的基础上做出来.
@下面是关键代码分析:
// 下拉刷新的原理- (void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView{if (scrollView.contentOffset.y < - 100) { [UIView animateWithDuration:1.0 animations:^{ // frame发生偏移,距离顶部150的距离(可自行设定)self.tableView.contentInset = UIEdgeInsetsMake(150.0f, 0.0f, 0.0f, 0.0f); } completion:^(BOOL finished) { /** * 发起网络请求,请求刷新数据 */ }];}}// 上拉加载的原理- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{NSLog(@"%f",scrollView.contentOffset.y);NSLog(@"%f",scrollView.frame.size.height);NSLog(@"%f",scrollView.contentSize.height);/*** 关键-->* scrollView一开始并不存在偏移量,但是会设定contentSize的大小,所以contentSize.height永远都会比contentOffset.y高一个手机屏幕的* 高度;上拉加载的效果就是每次滑动到底部时,再往上拉的时候请求更多,那个时候产生的偏移量,就能让contentOffset.y + 手机屏幕尺寸高大于这* 个滚动视图的contentSize.height*/if (scrollView.contentOffset.y + scrollView.frame.size.height >= scrollView.contentSize.height) { NSLog(@"%d %s",__LINE__,__FUNCTION__); [UIView commitAnimations]; [UIView animateWithDuration:1.0 animations:^{// frame发生的偏移量,距离底部往上提高60(可自行设定)self.tableView.contentInset = UIEdgeInsetsMake(0, 0, 60, 0); } completion:^(BOOL finished) { /** * 发起网络请求,请求加载更多数据 * 然后在数据请求回来的时候,将contentInset改为(0,0,0,0) */ }];}}
iOS UITableView下拉刷新上拉加载更多EGOTableViewPullRefresh类库使用初级剑侠篇（欢迎提建议和分享遇到的问题）
