IOS 下拉刷新 仿QQ

自己按照网上的下拉刷新demo自己做了一个，因为感觉网上下载的demo太繁琐了
下面贴上截图以及源代码
本文转自  http://www.999dh.net/article/iphone_ios_art/44.html  转载请注明！

工程下载地址在上面的链接页面里面，可以去下载！



//CMyDragView.h
#import <UIKit/UIKit.h>

#define MY_DRAG_HIGHT 50

@interface CMyDragView : UIView
{
    UIActivityIndicatorView * indicator;
    UIScrollView * scrView;
    UILabel * textLabel;
    UIImageView * imageView;
}

@property(retain,nonatomic) UIScrollView * scrView;
@property(retain,nonatomic) IBOutlet UIActivityIndicatorView * indicator;
@property(retain,nonatomic) IBOutlet UILabel * textLabel;
@property(retain,nonatomic) IBOutlet UIImageView * imageView;;


-(void)InitWithScroll:(UIScrollView*)scrollView;
-(void)BeginUpldate;
-(void)Upldating;
@end



CMyDragView.m
//
//  CMyDragView.m
//  myrefresh_demo
//
//  Created by chaoxiao zhuang on 12-12-22.
//  Copyright (c) 2012年 taizhouxueyuan. All rights reserved.
//

#import "CMyDragView.h"

@implementation CMyDragView

@synthesize indicator;
@synthesize textLabel;
@synthesize scrView;
@synthesize imageView;

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    // Drawing code
}
*/


-(void)InitWithScroll:(UIScrollView*)scrollView
{
    [scrollView addSubview:self];
    self.scrView = scrollView;
    
    [indicator setHidden:YES];
    [indicator stopAnimating];
    
    [self.textLabel setText:@"下拉刷新"];
    
    self.imageView.image = [UIImage imageNamed:@"blueArrow.png"];
}


-(void)BeginUpldate
{
    [self.textLabel setText:@"放开刷新"];
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.5];
    self.imageView.transform = CGAffineTransformMakeRotation(3.14);
    [UIView commitAnimations];
}

-(void)EndOfUpldate
{
    [indicator stopAnimating];
    [indicator setHidden:YES];
    
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0.2];
    [self.scrView setContentInset:UIEdgeInsetsMake(-MY_DRAG_HIGHT, 0, 0, 0)];
    [imageView setHidden:NO];
    self.imageView.transform = CGAffineTransformMakeRotation(0);
    [UIView commitAnimations];
}

-(void)Upldating
{
    [UIView beginAnimations:nil context:NULL];
    
    [imageView setHidden:YES];
    [indicator startAnimating];
    [indicator setHidden:NO];
    
    [self.scrView setContentInset:UIEdgeInsetsMake(0, 0, 0, 0)];
    [UIView commitAnimations];
    
    [self performSelector:@selector(EndOfUpldate) withObject:nil afterDelay:3];
}

@end

需要新建一个view，将其class 设置为CMyDragView，然后将这个view的simulated Metrics里面的 Status Bar 设置为 None



//
//  CRViewController.h
//  myrefresh_demo
//
//  Created by chaoxiao zhuang on 12-12-22.
//  Copyright (c) 2012年 taizhouxueyuan. All rights reserved.
//

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

@interface CRViewController : UIViewController<UIScrollViewDelegate>
{
    UIScrollView * scrollView;
    CMyDragView * dragView;
    
    BOOL bIsDrag;
}

@property(retain,nonatomic)IBOutlet UIScrollView * scrollView;
@property(retain,nonatomic) CMyDragView * dragView;

@end



//
//  CRViewController.m
//  myrefresh_demo
//
//  Created by chaoxiao zhuang on 12-12-22.
//  Copyright (c) 2012年 taizhouxueyuan. All rights reserved.
//

#import "CRViewController.h"

@implementation CRViewController

@synthesize scrollView;
@synthesize dragView;

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Release any cached data, images, etc that aren't in use.
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    NSArray * array = [[NSBundle mainBundle] loadNibNamed:@"CMyDragView" owner:self options:nil];
    self.dragView = [array objectAtIndex:0];
    
    [scrollView setContentSize:CGSizeMake(320, 480+MY_DRAG_HIGHT+15)];

    [dragView InitWithScroll:scrollView];
    
    [scrollView setContentInset:UIEdgeInsetsMake(-MY_DRAG_HIGHT, 0, 0, 0)];
    
    NSLog(@"viewDidLoad");
    
    bIsDrag = NO;
}


-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
    NSLog(@"DidEndDragging");
    
    bIsDrag = NO;
}


-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    NSLog(@"WillBeginDragging");
    
    bIsDrag = YES;
}

-(void)scrollViewDidScroll:(UIScrollView *)_scrollView
{
    NSLog(@"DidScroll y:%f",_scrollView.contentOffset.y);
    
    if( bIsDrag )
    {
        if( _scrollView.contentOffset.y <= 0 )
        {
            [self.dragView BeginUpldate];
        }
    }
    else
    {
        if( scrollView.contentOffset.y <= 0 )
        {
            [self.dragView Upldating];
        }
    }
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

@end


当然，还需要在xib里面放一些控件，scrollView  Label以及imageview等，这个具体可以在工程里面查看。