仿腾讯新闻下拉表格刷新数据
在开发一个项目时，需要刷新一个UITableView的数据，看到腾讯新闻的那种下拉table释放就刷新数据的体验效果蛮好，所以就仿照腾讯新闻，做了一个这样的Demo，有需要的朋友可以下载。
原理是这样的：放一个UIView在表格的上面，同时，这个UIView会被UISegmentedControl挡住，看不到，当下拉表格的时候，触发scrollViewDidScroll事件，在这个事件中，把UIView的位置随着拖动一起改变，然后当拖动到一定程度时，提示用户松开进行数据的刷新，当用户松开之后，触发scrollViewDidEndDragging事件，进行数据刷新，当刷新完毕之后，将UIView的位置复原。
效果图如下：
开始界面
拖动表格界面
正在刷新界面
代码如下：
RefreshNewsViewController.h
//
// RefreshNewsViewController.h
// RefreshNews
//
// Created by walkman Apple on 11-1-6.
// Copyright http://www.shouji138.com 手机主题下载 2011. All rights reserved.
//
#import <UIKit/UIKit.h>
@interface RefreshNewsViewController : UIViewController <UITableViewDelegate,UITableViewDataSource>{
UITableView *tableview;//表格
UISegmentedControl *titleSegment;
UIView* refreshView;
UILabel *statusLabel;
UIImageView *imgview;
BOOL isShoudRefresh;
UIImageView *SegmentBgView;
UIActivityIndicatorView *activeView;
bool isFinished;
NSInteger segSelectedIndex;
}
@property(nonatomic,retain) UITableView *tableview;
-(void)BeginGetData;
-(void)BindData;
-(void)hiddenview;
-(void)CallWS;
-(void)BeginThread;
-(void)UpdateUI;
@end
RefreshNewsViewController.m
//
// RefreshNewsViewController.m
// RefreshNews
//
// Created by walkman Apple on 11-1-6.
// Copyright http://www.shouji138.com 2011. All rights reserved.
//
#import "RefreshNewsViewController.h"
#define ROWSCOUNT 50
@implementation RefreshNewsViewController
@synthesize tableview;
/*
// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) {
// Custom initialization
}
return self;
}
*/
/*
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
}
*/
/*
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
*/
- (void)viewDidLoad {
[super viewDidLoad];
self.title = @"仿腾讯新闻下拉刷新数据演示";
titleSegment = [[UISegmentedControl alloc]initWithFrame:CGRectMake((self.view.bounds.size.width-328)/2,0, 328, 30)];
[titleSegment insertSegmentWithTitle:@"时政新闻" atIndex:0 animated:NO];
[titleSegment insertSegmentWithTitle:@"娱乐新闻" atIndex:1 animated:NO];
titleSegment.segmentedControlStyle = UISegmentedControlStyleBar;
titleSegment.selectedSegmentIndex = 0;
[titleSegment addTarget:self action:@selector(titleSegmentClick:) forControlEvents:UIControlEventValueChanged];
[self.view addSubview:titleSegment];
SegmentBgView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"segbg.png"]];
SegmentBgView.frame = CGRectMake(0, 0, 160, 30);
[self.view addSubview:SegmentBgView];
tableview = [[UITableView alloc] initWithFrame:CGRectMake(0, 30, 320, 360) style:UITableViewStylePlain];
tableview.delegate = self;
tableview.dataSource = self;
tableview.rowHeight = 35;
tableview.sectionHeaderHeight = 35;
[tableview setBackgroundColor:[UIColor clearColor]];
[self.view addSubview:tableview];
self.navigationController.toolbar.barStyle = UIBarStyleBlackOpaque;
refreshView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, 30)];
refreshView.backgroundColor = [UIColor clearColor];
imgview = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"1.png"]];
imgview.frame = CGRectMake(78,6, 20, 20);
[refreshView addSubview:imgview];
activeView = [[UIActivityIndicatorView alloc]
initWithFrame:CGRectMake(55,6, 20, 20)];
[activeView setActivityIndicatorViewStyle:UIActivityIndicatorViewStyleGray];
[activeView stopAnimating];
[refreshView addSubview:activeView];
statusLabel = [[UILabel alloc]initWithFrame :CGRectMake(100,0, 220, 30)];
statusLabel.text = @"下拉刷新...";
statusLabel.backgroundColor = [UIColor clearColor];
[refreshView addSubview:statusLabel];
[self.view addSubview:refreshView];
[self.view bringSubviewToFront:titleSegment];
[self.view bringSubviewToFront:SegmentBgView];
segSelectedIndex = 0;
[self BeginGetData];
}
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
if (isShoudRefresh) {
if (scrollView.contentOffset.y>-30) {
return;
}
}
//NSLog(@"%@,%f",@"scrollViewDidScroll",scrollView.contentOffset.y);
refreshView.frame = CGRectMake(0, -scrollView.contentOffset.y, 320, 30);
if (isShoudRefresh) {
return;
}
if (scrollView.contentOffset.y<-30) {
statusLabel.text = @"释放立即刷新...";
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.2];
imgview.transform = CGAffineTransformMakeRotation(-3.14);
[UIView commitAnimations];
}
else {
statusLabel.text = @"下拉刷新...";
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.2];
imgview.transform = CGAffineTransformMakeRotation(0);
[UIView commitAnimations];
}
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate{
//NSLog(@"%@,%f",@"scrollViewDidEndDragging",scrollView.contentOffset.y);
if (scrollView.contentOffset.y<-30) {
isShoudRefresh = YES;
}
else {
isShoudRefresh = NO;
}
if (isShoudRefresh && isFinished ) {
[activeView startAnimating];
statusLabel.text = @"正在刷新...";
tableview.scrollEnabled = NO;
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.5];
refreshView.frame = CGRectMake(0, 30, 320, 30);
CGRect rect = tableview.frame;
rect.origin.y +=30;
tableview.frame = rect;
[UIView commitAnimations];
[self BeginGetData];
}
}
-(void)titleSegmentClick:(id)sender{
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.2];
SegmentBgView.frame = CGRectMake(titleSegment.selectedSegmentIndex*160,0, 160, 30);
[UIView commitAnimations];
segSelectedIndex = titleSegment.selectedSegmentIndex;
if (titleSegment.selectedSegmentIndex ==0 ) {
}
else if(titleSegment.selectedSegmentIndex ==1) {
}
[self BindData];
}
-(void)BindData{
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.5];
imgview.transform = CGAffineTransformMakeRotation(0);
[UIView commitAnimations];
[self performSelector:@selector(hiddenview) withObject:nil afterDelay:0.5];
[tableview reloadData];
}
-(void)hiddenview{
isShoudRefresh = NO;
statusLabel.text = @"下拉刷新...";
tableview.scrollEnabled = YES;
[activeView stopAnimating];
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.5];
tableview.frame = CGRectMake(0, 30, 320, 360);
refreshView.frame = CGRectMake(0, 0, 320, 30);
[UIView commitAnimations];
}
-(void)BeginThread
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
isFinished = NO;
[self performSelectorInBackground:@selector(CallWS) withObject:nil];
[self performSelectorOnMainThread:@selector(UpdateUI) withObject:nil waitUntilDone:YES];
[pool release];
}
-(void)BeginGetData{
[NSThread detachNewThreadSelector:@selector(BeginThread) toTarget:self withObject:nil];
}
-(void)UpdateUI
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
if(!(isFinished))
{
[NSTimer scheduledTimerWithTimeInterval:0.2 target:self selector:@selector(UpdateUI)
userInfo:nil repeats:NO];
NSLog(@"waiting.....");
}
else {
[self BindData];
}
[pool release];
}
-(void)CallWS
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
//这里调用网络数据，是一个耗时的操作。
isFinished = YES;
[pool release];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return ROWSCOUNT;
}
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
//NSLog(@"%@",@"begin");
static NSString *CellIdentifier = @"Cell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier] autorelease];
}
cell.textLabel.text = [NSString stringWithFormat: @"第%d行%@",indexPath.row+1,segSelectedIndex==0?@"时政新闻":@"娱乐新闻"];
cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
return cell;
}
/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations
return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
*/
- (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
- (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)dealloc {
[tableview release];
[titleSegment release];
[refreshView release];
[activeView release];
[statusLabel release];
[imgview release];
[SegmentBgView release];
[super dealloc];
}
@end
其中用到了iPhone的动画效果，用户体验效果不错。有兴趣的朋友可以下载。
地址：
http://www.shouji138.com/files/RefreshNews.zip
也欢迎光临作者的小站：手机主题 http://www.shouji138.com/
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