列表下拉/上拉刷新:(二)支持下拉/上拉的ViewController基类

列表下拉/上拉刷新:(二)支持下拉/上拉的ViewController基类

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iPhone开发 2012-05-09 11:45
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uiviewinterfacemethodsheaderscrolldate

目标：定义包含tableView的rootViewController类，其它需要此功能的ViewController可以直接继承，通过重载开始刷新数据的函数，执行自己实际的刷新和加载操作，其他关于footer/header复位、滚动等操作交给基类处理。

头文件：

[cpp]
view plaincopyprint?

#import "EGORefreshTableHeaderView.h"

#import "EGORefreshTableFooterView.h"

#import "EGOViewCommon.h"

@interface RootViewController : UIViewController <EGORefreshTableDelegate, UITableViewDelegate, UITableViewDataSource>{

EGORefreshTableHeaderView *_refreshHeaderView;
EGORefreshTableFooterView *_refreshFooterView;

UITableView *_tableView;

// Reloading var should really be your tableviews datasource

// Putting it here for demo purposes

BOOL _reloading;
}

@property(nonatomic, retain)UITableView *tableView;

// create/remove footer/header view, reset the position of the footer/header views

-(void)setFooterView;
-(void)removeFooterView;
-(void)createHeaderView;
-(void)removeHeaderView;

// overide methods
-(void)beginToReloadData:(EGORefreshPos)aRefreshPos;
-(void)finishReloadingData;

@end

#import "EGORefreshTableHeaderView.h"
#import "EGORefreshTableFooterView.h"
#import "EGOViewCommon.h"

@interface RootViewController : UIViewController  <EGORefreshTableDelegate, UITableViewDelegate, UITableViewDataSource>{

EGORefreshTableHeaderView *_refreshHeaderView;
EGORefreshTableFooterView *_refreshFooterView;

UITableView *_tableView;

//  Reloading var should really be your tableviews datasource
//  Putting it here for demo purposes
BOOL _reloading;
}

@property(nonatomic, retain)UITableView *tableView;

// create/remove footer/header view, reset the position of the footer/header views
-(void)setFooterView;
-(void)removeFooterView;
-(void)createHeaderView;
-(void)removeHeaderView;

// overide methods
-(void)beginToReloadData:(EGORefreshPos)aRefreshPos;
-(void)finishReloadingData;

@end

实现:

[cpp]
view plaincopyprint?

#import "RootViewController.h"

@interface RootViewController (Private)
-(void)initTableViewWithRect:(CGRect)aRect;

@end

@implementation RootViewController
@synthesize tableView = _tableView;

- (void)viewDidLoad {
[super viewDidLoad];

// create the tableview
[self initTableViewWithRect:CGRectMake(self.view.bounds.origin.x,
self.view.bounds.origin.y,
self.view.frame.size.width,
self.view.frame.size.height-44.0)];
}

-(void)initTableViewWithRect:(CGRect)aRect{
_tableView = [[UITableView alloc] initWithFrame:aRect style:UITableViewStylePlain];
_tableView.delegate = self;
_tableView.dataSource = self;
_tableView.separatorStyle = UITableViewCellSeparatorStyleSingleLine;
_tableView.autoresizingMask = UIViewAutoresizingFlexibleWidth;
_tableView.backgroundColor = [UIColor clearColor];
[self.view addSubview: _tableView];
[_tableView release];
}

#pragma mark
#pragma methods for creating and removing the header view

-(void)createHeaderView{
if (_refreshHeaderView && [_refreshHeaderView superview]) {
[_refreshHeaderView removeFromSuperview];
}
_refreshHeaderView = [[EGORefreshTableHeaderView alloc] initWithFrame:
CGRectMake(0.0f, 0.0f - self.view.bounds.size.height,
self.view.frame.size.width, self.view.bounds.size.height)];
_refreshHeaderView.delegate = self;

[_tableView addSubview:_refreshHeaderView];

[_refreshHeaderView refreshLastUpdatedDate];
}

-(void)removeHeaderView{
if (_refreshHeaderView && [_refreshHeaderView superview]) {
[_refreshHeaderView removeFromSuperview];
}
_refreshHeaderView = nil;
}

-(void)setFooterView{
// if the footerView is nil, then create it, reset the position of the footer

CGFloat height = MAX(_tableView.contentSize.height, _tableView.frame.size.height);
if (_refreshFooterView && [_refreshFooterView superview]) {
// reset position
_refreshFooterView.frame = CGRectMake(0.0f,
height,
_tableView.frame.size.width,
self.view.bounds.size.height);
}else {
// create the footerView
_refreshFooterView = [[EGORefreshTableFooterView alloc] initWithFrame:
CGRectMake(0.0f, height,
_tableView.frame.size.width, self.view.bounds.size.height)];
_refreshFooterView.delegate = self;
[_tableView addSubview:_refreshFooterView];
}

if (_refreshFooterView) {
[_refreshFooterView refreshLastUpdatedDate];
}
}

-(void)removeFooterView{
if (_refreshFooterView && [_refreshFooterView superview]) {
[_refreshFooterView removeFromSuperview];
}
_refreshFooterView = nil;
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return YES;
}

#pragma mark-
#pragma mark force to show the refresh headerView

-(void)showRefreshHeader:(BOOL)animated{
if (animated)
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.2];
self.tableView.contentInset = UIEdgeInsetsMake(60.0f, 0.0f, 0.0f, 0.0f);
// scroll the table view to the top region

[self.tableView scrollRectToVisible:CGRectMake(0, 0.0f, 1, 1) animated:NO];
[UIView commitAnimations];
}
else
{
self.tableView.contentInset = UIEdgeInsetsMake(60.0f, 0.0f, 0.0f, 0.0f);
[self.tableView scrollRectToVisible:CGRectMake(0, 0.0f, 1, 1) animated:NO];
}

}

#pragma mark -
#pragma mark overide UITableViewDataSource methods

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 0;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return 0;
}

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

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}

// Configure the cell.

return cell;
}

#pragma mark -
#pragma mark data reloading methods that must be overide by the subclass

-(void)beginToReloadData:(EGORefreshPos)aRefreshPos{

// should be calling your tableviews data source model to reload

_reloading = YES;

// overide, the actual loading data operation is done in the subclass

}

#pragma mark -
#pragma mark method that should be called when the refreshing is finished

- (void)finishReloadingData{

// model should call this when its done loading

_reloading = NO;

if (_refreshHeaderView) {
[_refreshHeaderView egoRefreshScrollViewDataSourceDidFinishedLoading:_tableView];
}

if (_refreshFooterView) {
[_refreshFooterView egoRefreshScrollViewDataSourceDidFinishedLoading:_tableView];
[self setFooterView];
}

// overide, the actula reloading tableView operation and reseting position operation is done in the subclass

}

#pragma mark -
#pragma mark UIScrollViewDelegate Methods

- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
if (_refreshHeaderView) {
[_refreshHeaderView egoRefreshScrollViewDidScroll:scrollView];
}

if (_refreshFooterView) {
[_refreshFooterView egoRefreshScrollViewDidScroll:scrollView];
}
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
if (_refreshHeaderView) {
[_refreshHeaderView egoRefreshScrollViewDidEndDragging:scrollView];
}

if (_refreshFooterView) {
[_refreshFooterView egoRefreshScrollViewDidEndDragging:scrollView];
}
}

#pragma mark -
#pragma mark EGORefreshTableDelegate Methods

- (void)egoRefreshTableDidTriggerRefresh:(EGORefreshPos)aRefreshPos{

[self beginToReloadData:aRefreshPos];

}

- (BOOL)egoRefreshTableDataSourceIsLoading:(UIView*)view{

return _reloading; // should return if data source model is reloading

}

// if we don't realize this method, it won't display the refresh timestamp

- (NSDate*)egoRefreshTableDataSourceLastUpdated:(UIView*)view{

return [NSDate date]; // should return date data source was last changed

}

#pragma mark -
#pragma mark Memory Management

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}

- (void)viewDidUnload {
SAFE_RELEASE(_refreshHeaderView)
SAFE_RELEASE(_refreshFooterView)
}

- (void)dealloc {
[super dealloc];
}

#import "RootViewController.h"

@interface RootViewController (Private)
-(void)initTableViewWithRect:(CGRect)aRect;

@end

@implementation RootViewController
@synthesize tableView = _tableView;

- (void)viewDidLoad {
[super viewDidLoad];

// create the tableview
[self initTableViewWithRect:CGRectMake(self.view.bounds.origin.x,
self.view.bounds.origin.y,
self.view.frame.size.width,
self.view.frame.size.height-44.0)];
}

-(void)initTableViewWithRect:(CGRect)aRect{
_tableView = [[UITableView alloc] initWithFrame:aRect  style:UITableViewStylePlain];
_tableView.delegate = self;
_tableView.dataSource = self;
_tableView.separatorStyle = UITableViewCellSeparatorStyleSingleLine;
_tableView.autoresizingMask = UIViewAutoresizingFlexibleWidth;
_tableView.backgroundColor = [UIColor clearColor];
[self.view addSubview: _tableView];
[_tableView release];
}

#pragma mark
#pragma methods for creating and removing the header view

-(void)createHeaderView{
if (_refreshHeaderView && [_refreshHeaderView superview]) {
[_refreshHeaderView removeFromSuperview];
}
_refreshHeaderView = [[EGORefreshTableHeaderView alloc] initWithFrame:
CGRectMake(0.0f, 0.0f - self.view.bounds.size.height,
self.view.frame.size.width, self.view.bounds.size.height)];
_refreshHeaderView.delegate = self;

[_tableView addSubview:_refreshHeaderView];

[_refreshHeaderView refreshLastUpdatedDate];
}

-(void)removeHeaderView{
if (_refreshHeaderView && [_refreshHeaderView superview]) {
[_refreshHeaderView removeFromSuperview];
}
_refreshHeaderView = nil;
}

-(void)setFooterView{
// if the footerView is nil, then create it, reset the position of the footer
CGFloat height = MAX(_tableView.contentSize.height, _tableView.frame.size.height);
if (_refreshFooterView && [_refreshFooterView superview]) {
// reset position
_refreshFooterView.frame = CGRectMake(0.0f,
height,
_tableView.frame.size.width,
self.view.bounds.size.height);
}else {
// create the footerView
_refreshFooterView = [[EGORefreshTableFooterView alloc] initWithFrame:
CGRectMake(0.0f, height,
_tableView.frame.size.width, self.view.bounds.size.height)];
_refreshFooterView.delegate = self;
[_tableView addSubview:_refreshFooterView];
}

if (_refreshFooterView) {
[_refreshFooterView refreshLastUpdatedDate];
}
}

-(void)removeFooterView{
if (_refreshFooterView && [_refreshFooterView superview]) {
[_refreshFooterView removeFromSuperview];
}
_refreshFooterView = nil;
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
return YES;
}

#pragma mark-
#pragma mark force to show the refresh headerView
-(void)showRefreshHeader:(BOOL)animated{
if (animated)
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.2];
self.tableView.contentInset = UIEdgeInsetsMake(60.0f, 0.0f, 0.0f, 0.0f);
// scroll the table view to the top region
[self.tableView scrollRectToVisible:CGRectMake(0, 0.0f, 1, 1) animated:NO];
[UIView commitAnimations];
}
else
{
self.tableView.contentInset = UIEdgeInsetsMake(60.0f, 0.0f, 0.0f, 0.0f);
[self.tableView scrollRectToVisible:CGRectMake(0, 0.0f, 1, 1) animated:NO];
}

}

#pragma mark -
#pragma mark overide UITableViewDataSource methods

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 0;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return 0;
}

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

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}

// Configure the cell.

return cell;
}

#pragma mark -
#pragma mark data reloading methods that must be overide by the subclass

-(void)beginToReloadData:(EGORefreshPos)aRefreshPos{

//  should be calling your tableviews data source model to reload
_reloading = YES;

// overide, the actual loading data operation is done in the subclass
}

#pragma mark -
#pragma mark method that should be called when the refreshing is finished
- (void)finishReloadingData{

//  model should call this when its done loading
_reloading = NO;

if (_refreshHeaderView) {
[_refreshHeaderView egoRefreshScrollViewDataSourceDidFinishedLoading:_tableView];
}

if (_refreshFooterView) {
[_refreshFooterView egoRefreshScrollViewDataSourceDidFinishedLoading:_tableView];
[self setFooterView];
}

// overide, the actula reloading tableView operation and reseting position operation is done in the subclass
}

#pragma mark -
#pragma mark UIScrollViewDelegate Methods

- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
if (_refreshHeaderView) {
[_refreshHeaderView egoRefreshScrollViewDidScroll:scrollView];
}

if (_refreshFooterView) {
[_refreshFooterView egoRefreshScrollViewDidScroll:scrollView];
}
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
if (_refreshHeaderView) {
[_refreshHeaderView egoRefreshScrollViewDidEndDragging:scrollView];
}

if (_refreshFooterView) {
[_refreshFooterView egoRefreshScrollViewDidEndDragging:scrollView];
}
}

#pragma mark -
#pragma mark EGORefreshTableDelegate Methods

- (void)egoRefreshTableDidTriggerRefresh:(EGORefreshPos)aRefreshPos{

[self beginToReloadData:aRefreshPos];

}

- (BOOL)egoRefreshTableDataSourceIsLoading:(UIView*)view{

return _reloading; // should return if data source model is reloading

}

// if we don't realize this method, it won't display the refresh timestamp
- (NSDate*)egoRefreshTableDataSourceLastUpdated:(UIView*)view{

return [NSDate date]; // should return date data source was last changed

}

#pragma mark -
#pragma mark Memory Management

- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
}

- (void)viewDidUnload {
SAFE_RELEASE(_refreshHeaderView)
SAFE_RELEASE(_refreshFooterView)
}

- (void)dealloc {
[super dealloc];
}

具体使用：

可以在一加载完view就createHeaderView，因为它总是在列表的最顶部，位置不会变化。不想要的时候remove。

footerView要在[tableView reloadData]之后才能设置，因为footer的位置取决于tableView的ContentSize。一般来讲：加载第一页数据之前，不需要创建footer，等到第一页的数据加载完成之后调用setFooterView（如果不存footer，会创建，否则重置位置），来首次创建footer，后续加载第二页、第三页...的时候，也是加载完成reloadData，之后setFooterView重新调整其位置。

重载-(void)beginToReloadData:(EGORefreshPos)aRefreshPos，具体实现你想做的事情，例如：

[cpp]
view plaincopyprint?

#pragma mark-
#pragma mark overide methods
-(void)beginToReloadData:(EGORefreshPos)aRefreshPos{
[super beginToReloadData:aRefreshPos];

if (aRefreshPos == EGORefreshHeader) {
// pull down to refresh data

[self performSelector:@selector(testRealRefreshDataSource) withObject:nil afterDelay:2.0];
}else if(aRefreshPos == EGORefreshFooter){
// pull up to load more data

[self performSelector:@selector(testRealLoadMoreData) withObject:nil afterDelay:2.0];
}
}

#pragma mark-
#pragma mark overide methods
-(void)beginToReloadData:(EGORefreshPos)aRefreshPos{
[super beginToReloadData:aRefreshPos];

if (aRefreshPos == EGORefreshHeader) {
// pull down to refresh data
[self performSelector:@selector(testRealRefreshDataSource) withObject:nil afterDelay:2.0];
}else if(aRefreshPos == EGORefreshFooter){
// pull up to load more data
[self performSelector:@selector(testRealLoadMoreData) withObject:nil afterDelay:2.0];
}
}

如上，可以在这里触发联网操作获取数据，我用了延时操作来模拟而已。

给出我的完整的测试界面代码

示例：

[cpp]
view plaincopyprint?

#import "MyTestViewController.h"

@interface MyTestViewController ()

@end

@implementation MyTestViewController

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.

// test data
_totalNumberOfRows = 100;
_refreshCount = 0;
_dataSource = [[NSMutableArray alloc] initWithCapacity:4];

// set header
[self createHeaderView];

// the footer should be set after the data of tableView has been loaded, the frame of footer is according to the contentSize of tableView

// here, actually begin too load your data, eg: from the netserver

[self performSelector:@selector(testFinishedLoadData) withObject:nil afterDelay:2.0f];
}

- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.

}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

#pragma mark -
#pragma mark overide UITableViewDataSource methods

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return _dataSource?1:0;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return _dataSource?_dataSource.count:0;
}

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

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}

// Configure the cell.

if (_dataSource && indexPath.row < _dataSource.count) {
cell.textLabel.text = [_dataSource objectAtIndex:indexPath.row];
}

return cell;
}

#pragma mark-
#pragma mark overide methods
-(void)beginToReloadData:(EGORefreshPos)aRefreshPos{
[super beginToReloadData:aRefreshPos];

if (aRefreshPos == EGORefreshHeader) {
// pull down to refresh data

[self performSelector:@selector(testRealRefreshDataSource) withObject:nil afterDelay:2.0];
}else if(aRefreshPos == EGORefreshFooter){
// pull up to load more data

[self performSelector:@selector(testRealLoadMoreData) withObject:nil afterDelay:2.0];
}
}

-(void)testRealRefreshDataSource{
NSInteger count = _dataSource?_dataSource.count:0;

[_dataSource removeAllObjects];
_refreshCount ++;

for (int i = 0; i < count; i++) {
NSString *newString = [NSString stringWithFormat:@"%d_new label number %d", _refreshCount,i];
[_dataSource addObject:newString];
}

// after refreshing data, call finishReloadingData to reset the header/footer view

[_tableView reloadData];
[self finishReloadingData];
}

-(void)testRealLoadMoreData{
NSInteger count = _dataSource?_dataSource.count:0;
NSString *stringFormat;
if (_refreshCount == 0) {
stringFormat = @"label number %d";
}else {
stringFormat = [NSString stringWithFormat:@"%d_new label number ", _refreshCount];
stringFormat = [stringFormat stringByAppendingString:@"%d"];
}

for (int i = 0; i < 20; i++) {
NSString *newString = [NSString stringWithFormat:stringFormat, i+count];
if (_dataSource == nil) {
_dataSource = [[NSMutableArray alloc] initWithCapacity:4];

}
[_dataSource addObject:newString];
}

_loadMoreCount ++;

// after refreshing data, call finishReloadingData to reset the header/footer view

[_tableView reloadData];
[self finishReloadingData];
}

-(void)testFinishedLoadData{
for (int i = 0; i < 20; i++) {
NSString *tableString = [NSString stringWithFormat:@"label number %d", i];
[_dataSource addObject:tableString];
}

// after loading data, should reloadData and set the footer to the proper position

[self.tableView reloadData];
[self setFooterView];
}

#import "MyTestViewController.h"

@interface MyTestViewController ()

@end

@implementation MyTestViewController

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.

// test data
_totalNumberOfRows = 100;
_refreshCount = 0;
_dataSource = [[NSMutableArray alloc] initWithCapacity:4];

// set header
[self createHeaderView];

// the footer should be set after the data of tableView has been loaded, the frame of footer is according to the contentSize of tableView
// here, actually begin too load your data, eg: from the netserver

[self performSelector:@selector(testFinishedLoadData) withObject:nil afterDelay:2.0f];
}

- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

#pragma mark -
#pragma mark overide UITableViewDataSource methods

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return _dataSource?1:0;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return _dataSource?_dataSource.count:0;
}

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

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}

// Configure the cell.
if (_dataSource && indexPath.row < _dataSource.count) {
cell.textLabel.text = [_dataSource objectAtIndex:indexPath.row];
}

return cell;
}

#pragma mark-
#pragma mark overide methods
-(void)beginToReloadData:(EGORefreshPos)aRefreshPos{
[super beginToReloadData:aRefreshPos];

if (aRefreshPos == EGORefreshHeader) {
// pull down to refresh data
[self performSelector:@selector(testRealRefreshDataSource) withObject:nil afterDelay:2.0];
}else if(aRefreshPos == EGORefreshFooter){
// pull up to load more data
[self performSelector:@selector(testRealLoadMoreData) withObject:nil afterDelay:2.0];
}
}

-(void)testRealRefreshDataSource{
NSInteger count = _dataSource?_dataSource.count:0;

[_dataSource removeAllObjects];
_refreshCount ++;

for (int i = 0; i < count; i++) {
NSString *newString = [NSString stringWithFormat:@"%d_new label number %d", _refreshCount,i];
[_dataSource addObject:newString];
}

// after refreshing data, call finishReloadingData to reset the header/footer view
[_tableView reloadData];
[self finishReloadingData];
}

-(void)testRealLoadMoreData{
NSInteger count = _dataSource?_dataSource.count:0;
NSString *stringFormat;
if (_refreshCount == 0) {
stringFormat = @"label number %d";
}else {
stringFormat = [NSString stringWithFormat:@"%d_new label number ", _refreshCount];
stringFormat = [stringFormat stringByAppendingString:@"%d"];
}

for (int i = 0; i < 20; i++) {
NSString *newString = [NSString stringWithFormat:stringFormat, i+count];
if (_dataSource == nil) {
_dataSource = [[NSMutableArray alloc] initWithCapacity:4];

}
[_dataSource addObject:newString];
}

_loadMoreCount ++;

// after refreshing data, call finishReloadingData to reset the header/footer view
[_tableView reloadData];
[self finishReloadingData];
}

-(void)testFinishedLoadData{
for (int i = 0; i < 20; i++) {
NSString *tableString = [NSString stringWithFormat:@"label number %d", i];
[_dataSource addObject:tableString];
}

// after loading data, should reloadData and set the footer to the proper position
[self.tableView reloadData];
[self setFooterView];
}

注：因为还要做一些进一步的加工，例如强制刷新等，所以代码还没写完，例如一进来的延迟2秒加载数据，感觉很奇怪，其实是为了后续要写的东西预留的，凑合看吧。