为练手写了一个小的上拉载入很多其它下拉刷新的小的Dome 。

没有太多的技术含量，仅仅是作为新手的启示用。是上一篇下拉载入的扩展。先看一下那个再看这个就easy非常多。

Dome下载：http://download.csdn.net/detail/u010123208/8062715

先来梳理一下：

上拉家在很多其它就是上拉之后在底部现实一个视图，用来提示用户上拉载入很多其它，假设用户上拉就出发事件。进行载入并在试图中给予提示，同一时候后台载入数据，将加入的数据加入数据数组，最后又一次导入列表；

下拉刷新相同的操作，仅仅只是就是将数组清空又一次来导入数据；

首先我们要创建两个view 一个是顶部显示，一个在底部显示 ；

在view中要显示如今文字，一张图片，一个活动指示框（当进行网络请求载入数据的时候显示。其它时候隐藏），假设不太理解下载Dome看一下就知道了。

typedef enum {
    InsertStateNomal,    //寻常状态
    InsertStateDrapUp,   //上拉状态
    InsertStateDrapDown, //下拉状态
    InsertStateRun,      //正在载入的状态
}InsertState;

@interface HeadView : UIView

@property (nonatomic,strong) UIImageView *imageView; 
@property (nonatomic,strong) UILabel *label;
@property (nonatomic,assign) InsertState insertState;
@property (nonatomic,strong) UIActivityIndicatorView *activity;

- (void)setInsertNomal;  
- (void)setInsertDrapDown;
- (void)setInsertRun;
@end


@interface FootView : UIView

@property (nonatomic,strong) UIImageView *imageView;
@property (nonatomic,strong) UILabel *label;
@property (nonatomic,assign) InsertState insertState;
@property (nonatomic,strong) UIActivityIndicatorView *activity;

- (void)setInsertNomal;
- (void)setInsertDrapDoUp;
- (void)setInsertRun;

@end

枚举用来指示视图的当前状态；

事实上两个视图的内容什么的都全然一样；

//
//  InsertView.m
//  RefreshDome
//
//  Created by 小屁孩 on 14-10-16.
//  Copyright (c) 2014年 XS. All rights reserved.
//

#import "InsertView.h"

@implementation HeadView

@synthesize imageView;
@synthesize label;
@synthesize insertState;
@synthesize activity;

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        
        self.backgroundColor = [UIColor orangeColor];
        //图片
        imageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"arrow.png"]];
        imageView.frame = CGRectMake(20, frame.size.height-60, 30, 50);
        [self addSubview:imageView];
        
        //显示的文字
        label = [[UILabel alloc]initWithFrame:CGRectMake(60, frame.size.height-60, 250, 50)];
        label.text = @"下拉刷新...";
        label.textAlignment = NSTextAlignmentCenter;
        [self addSubview:label];
        
        //状态
        insertState = InsertStateNomal;
        
        //活动指示器
        activity = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
        activity.frame = CGRectMake(20,frame.size.height-60, 30, 50);
        [self addSubview:activity];
    }
    return self;
}

//初始状态
-(void)setInsertNomal
{
    insertState = InsertStateNomal;
    label.text = @"下拉刷新.....";
    imageView.layer.transform = CATransform3DMakeRotation(M_PI*2, 0, 0, 1);
    [activity stopAnimating];
    imageView.hidden =NO;
}

//下拉状态
- (void)setInsertDrapDown
{
    insertState = InsertStateDrapDown;
    [UIView beginAnimations:nil context:nil];
    label.text = @"释放后刷新.....";
    imageView.layer.transform = CATransform3DMakeRotation(M_PI, 0, 0, 1);
    [UIView commitAnimations];
    
}

//刷新状态
- (void)setInsertRun
{
    insertState =InsertStateRun;
    label.text = @"正在刷新.....";
    imageView.hidden = YES;
    [activity startAnimating];
}
@end


@implementation FootView

@synthesize imageView;
@synthesize label;
@synthesize insertState;
@synthesize activity;

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        
        self.backgroundColor = [UIColor orangeColor];
        //图片
        imageView = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"arrow.png"]];
        imageView.layer.transform = CATransform3DMakeRotation(M_PI , 0, 0, 1);
        imageView.frame = CGRectMake(20, 10, 30, 50);
        [self addSubview:imageView];
        
        //文字
        label = [[UILabel alloc]initWithFrame:CGRectMake(60, 10, 250, 50)];
        label.text = @"上拉载入很多其它.....";
        label.textAlignment = NSTextAlignmentCenter;
        [self addSubview:label];
        
        //状态
        insertState = InsertStateNomal;
        
        //活动指示器
        activity = [[UIActivityIndicatorView alloc]initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
        activity.frame = CGRectMake(20, 10, 30, 50);
        [self addSubview:activity];
    }
    return self;
}

//初始状态
- (void)setInsertNomal
{
    insertState = InsertStateNomal;
    label.text = @"上拉载入很多其它.....";
    imageView.layer.transform = CATransform3DMakeRotation(M_PI , 0, 0, 1);
    [activity stopAnimating];
    imageView.hidden =NO;
}

//上拉状态
- (void)setInsertDrapDoUp
{
    insertState = InsertStateDrapUp;
    [UIView beginAnimations:nil context:nil];
    label.text = @"释放后载入很多其它.....";
    imageView.layer.transform = CATransform3DMakeRotation(M_PI * 2, 0, 0, 1);
    [UIView commitAnimations];
}

//载入状态
- (void)setInsertRun
{
    insertState = InsertStateRun;
    label.text = @"正在载入.....";
    imageView.hidden = YES;
    [activity startAnimating];
}
@end

最后就是列表了；

事实上在这里面须要注意的：

• 要如何为表格加入视图
• 加入的底部视图随着内容的增多，是不断变化的（这里我用了KVO来控制，当数组元素变化后处理位置）
• 当完毕下拉或者上拉的时候。短暂的视图显示怎么来控制
• 上拉下拉的推断（UIScrollview代理）条件；

#import <UIKit/UIKit.h>
#import "InsertView.h"

@interface ViewController : UIViewController<UITableViewDataSource,UITableViewDelegate,UIScrollViewDelegate>

@property (weak, nonatomic) IBOutlet UITableView *table;
@property (nonatomic,strong) NSMutableArray *tableArray;


@end

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController
{
    HeadView *headView;
    FootView *footView;
}

@synthesize tableArray;
@synthesize table;


- (void)viewDidLoad
{
    [super viewDidLoad];
    table.frame = CGRectMake(0, 20, 320, [[UIScreen mainScreen]bounds].size.height-20);
    table.delegate = self;
    table.dataSource = self;
    table.tableFooterView = [[UIView alloc]init];
    
    //下拉头部视图
    headView = [[HeadView alloc]initWithFrame:CGRectMake(0, -251, DEVICE_FRAME.size.width, 251)];
    [table addSubview:headView];
    
    //上拉底部视图
    footView = [[FootView alloc]initWithFrame:CGRectMake(0, table.frame.size.height, DEVICE_FRAME.size.width, 251)];
    [table addSubview:footView];
    
    //初始化数组
    tableArray = [NSMutableArray array];
    for (int i = 0; i<15; i++) {
        NSURL *url=[NSURL URLWithString:@"http://www.sinaimg.cn/qc/photo_auto/chezhan/2012/50/00/15/80046_950.jpg"];
        UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:url]];
        [tableArray addObject:image];
    }
    
    float hight =tableArray.count * 60 ;
    if (tableArray.count * 60  < [[UIScreen mainScreen]bounds].size.height ) {
        hight = table.frame.size.height;
    }
    footView.frame = CGRectMake(0, hight, 320, 251);
    
    [self addObserver:self forKeyPath:@"tableArray" options:NSKeyValueObservingOptionNew context:nil];
    
}

- (void) addtableMutableArray
{
    for (int i = 0; i<5; i++) {
        NSURL *url=[NSURL URLWithString:@"http://www.sinaimg.cn/qc/photo_auto/chezhan/2012/50/00/15/80046_950.jpg"];
        UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:url]];
        [self.tableArray addObject:image];
    }
    self.tableArray = tableArray;
    [footView setInsertNomal];
    [self performSelectorOnMainThread:@selector(endThread) withObject:nil waitUntilDone:NO];
}

- (void)endThread
{
    
    [UIView beginAnimations:nil context:nil];
    table.contentInset = UIEdgeInsetsMake(0, 0, 0, 0);
    [UIView commitAnimations];
    [table reloadData];
    NSLog(@"%d",tableArray.count);
}


- (void) refesh
{
    NSMutableArray *array = [NSMutableArray array];
    for (int i = 0; i<15; i++) {
        NSURL *url=[NSURL URLWithString:@"http://wenwen.sogou.com/p/20110923/20110923201826-1347223277.jpg"];
        UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:url]];
        [array addObject:image];
    }
    self.tableArray = array;
    [headView setInsertNomal];
    [self performSelectorOnMainThread:@selector(endThread) withObject:nil waitUntilDone:NO];
}


#pragma mark KVO
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    NSMutableArray *array = [change objectForKey:@"new"];
    float hight =array.count * 60;
    if (array.count * 60  < [[UIScreen mainScreen]bounds].size.height ) {
        hight = [[UIScreen mainScreen]bounds].size.height;
    }
    footView.frame = CGRectMake(0, hight, 320, 251);
    
}

#pragma mark tabledelegate

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return  tableArray.count;
}
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 60;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *identityCell = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:identityCell];
    if (cell == nil) {
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:identityCell];
    }
    cell.imageView.image = [tableArray objectAtIndex:indexPath.row];
    cell.textLabel.text = @"NibBi";
    return cell;
}


#pragma mark - scrolldelegae

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
    if (headView.insertState == InsertStateDrapDown) {
        [UIView beginAnimations:nil context:nil];
        table.contentInset = UIEdgeInsetsMake(70, 0, 0, 0);
        [headView setInsertRun];
        [UIView commitAnimations];
        [self performSelectorInBackground:@selector(refesh) withObject:nil];

    }
    if (footView.insertState == InsertStateDrapUp) {
        [UIView beginAnimations:nil context:nil];
        table.contentInset = UIEdgeInsetsMake(0, 0, 70, 0);
        [footView setInsertRun];
        [UIView commitAnimations];
        [self performSelectorInBackground:@selector(addtableMutableArray) withObject:nil];
    }
}

-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
  // NSLog(@"%f",scrollView.contentOffset.y);
    //上拉载入很多其它转换
    if (scrollView.contentOffset.y > scrollView.contentSize.height - scrollView.frame.size.height + 60 && footView.insertState == InsertStateNomal) {
        [UIView beginAnimations:nil context:nil];
        [footView setInsertDrapDoUp];
        [UIView commitAnimations];
        
    }
    //下拉刷新转换
    if (scrollView.contentOffset.y < -60 && headView.insertState == InsertStateNomal)
    {
        [UIView beginAnimations:nil context:nil];
        [headView setInsertDrapDown];
        [UIView commitAnimations];
    }
}



@end

本文转自mfrbuaa博客园博客，原文链接：http://www.cnblogs.com/mfrbuaa/p/5099195.html，如需转载请自行联系原作者