项目中需要用到pull to refresh这个功能， 从网上找了下找到了这个：
https://github.com/leah/PullToRefresh
。
这个代码对我来说有一个很大的问题。其中拖动刷新的实现是放在TableViewControllerL里的，我要的放在
自定义UIView中的实现。经过一番改造终于实现了出来。
首先，我们整个的拖动刷新都是从拖动操作发起的，如下的方法必须予以合适的实现：
拖动相关的了解之后。拖动之前需要在初始化方法里做好准备工作。
设置下什么“拖动获取更多”，“加载中。。。”之类的文字。还有箭头，ActivityIndicator之类的界面元素。
然后就是根据加载的不同状态设置界面语速的文字，位置和隐藏与否。代码：
最后最重要就是加载了。在加载方法中填充必要的代码，或者在子类的加载方法中添加（如果你要继承的话，最好还是继承一下）。示例：
完整代码如下：
.m
这个代码对我来说有一个很大的问题。其中拖动刷新的实现是放在TableViewControllerL里的，我要的放在
自定义UIView中的实现。经过一番改造终于实现了出来。
首先，我们整个的拖动刷新都是从拖动操作发起的，如下的方法必须予以合适的实现：
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// 拖动动作开始，如果正在获取更多信息不做任何操作
- (
void
)scrollViewWillBeginDragging:(UIScrollView *)scrollView;
// 拖动中。根据是否已经开始加载信息设置tableView的contentInset值
- (
void
)scrollViewDidScroll:(UIScrollView *)scrollView;
// 拖动完成，开始加载。如果上次的加载没有完成，不做任何操作
- (
void
)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(
BOOL
)decelerate;
|
拖动相关的了解之后。拖动之前需要在初始化方法里做好准备工作。
设置下什么“拖动获取更多”，“加载中。。。”之类的文字。还有箭头，ActivityIndicator之类的界面元素。
然后就是根据加载的不同状态设置界面语速的文字，位置和隐藏与否。代码：
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#pragma mark -
#pragma mark Pull to refresh methods
- (
void
)setUpStrings{
_textPull = [[
NSString
alloc]initWithString:@
"拖动获取更多。。。"
];
_textRelease = [[
NSString
alloc]initWithString:@
"释放获取更多。。。"
];
_textRelease = [[
NSString
alloc]initWithString:@
"加载中。。。"
];
}
- (
void
)addPullToRefreshHeader{
CGRect mainBounds = [[UIScreen mainScreen] bounds];
_refreshHeaderView = [[UIView alloc]initWithFrame:CGRectMake(0, 0 - REFRESH_HEADER_VIEW, mainBounds.size.width, REFRESH_HEADER_VIEW)];
_refreshHeaderView.backgroundColor = [UIColor clearColor];
_refreshLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, mainBounds.size.width, REFRESH_HEADER_VIEW)];
_refreshLabel.backgroundColor = [UIColor clearColor];
_refreshLabel.font = [UIFont boldSystemFontOfSize:12.f];
_refreshLabel.textAlignment = UITextAlignmentCenter;
_refreshArrow = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@
"arrow.png"
]];
_refreshArrow.frame = CGRectMake(floorf((REFRESH_HEADER_VIEW - 20) / 2), floorf((REFRESH_HEADER_VIEW - 20) / 2), 27, 44);
_refreshSpinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
_refreshSpinner.frame = CGRectMake(floorf((REFRESH_HEADER_VIEW - 20) / 2), floorf((REFRESH_HEADER_VIEW - 20) / 2), 27, 44);
_refreshSpinner.hidesWhenStopped =
YES
;
[_refreshHeaderView addSubview:_refreshLabel];
[_refreshHeaderView addSubview:_refreshArrow];
[_refreshHeaderView addSubview:_refreshSpinner];
[
self
.weiboTableView addSubview:_refreshHeaderView];
}
- (
void
)startLoading{
_isLoading =
YES
;
[UIView animateWithDuration:0.3f animations:^{
self
.weiboTableView.contentInset = UIEdgeInsetsMake(REFRESH_HEADER_VIEW, 0, 0, 0);
_refreshLabel.text =
self
.textLoading;
_refreshArrow.hidden =
YES
;
[_refreshSpinner startAnimating];
}];
[
self
refresh];
}
- (
void
)stopLoadingComplete {
// Reset the header
_refreshLabel.text =
self
.textPull;
_refreshArrow.hidden =
NO
;
[_refreshSpinner stopAnimating];
}
- (
void
)stopLoading{
_isLoading =
NO
;
[UIView animateWithDuration:0.3f animations:^{
self
.weiboTableView.contentInset = UIEdgeInsetsZero;
[_refreshArrow layer].transform = CATransform3DMakeRotation(M_PI * 2, 0, 0, 1);
}
completion:^(
BOOL
finished){
[
self
performSelector:
@selector
(stopLoadingComplete)];
}];
}
- (
void
)refresh{
[
self
performSelector:
@selector
(stopLoading) withObject:
nil
afterDelay:5.f];
}
|
最后最重要就是加载了。在加载方法中填充必要的代码，或者在子类的加载方法中添加（如果你要继承的话，最好还是继承一下）。示例：
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- (
void
)refresh{
// 加载功能代码
// 最后一句必不可少
[
self
performSelector:
@selector
(stopLoading) withObject:
nil
afterDelay:5.f];
}
|
完整代码如下：
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//
// ScrollRefreshPageView.h
// Sample Project
//
// Created by Bruce Li (mr_bruce).
// QQ: 1828099940
//
#import <UIKit/UIKit.h>
#import "TSPageView.h"
@interface
ScrollRefreshPageView : UIView {
UIView *_refreshHeaderView;
UILabel *_refreshLabel;
UIImageView *_refreshArrow;
UIActivityIndicatorView *_refreshSpinner;
BOOL
_isDragging;
BOOL
_isLoading;
NSString
*_textPull;
NSString
*_textRelease;
NSString
*_textLoading;
}
@property
(
nonatomic
,
copy
)
NSString
*textPull;
@property
(
nonatomic
,
copy
)
NSString
*textRelease;
@property
(
nonatomic
,
copy
)
NSString
*textLoading;
- (
void
)setUpStrings;
- (
void
)addPullToRefreshHeader;
- (
void
)startLoading;
- (
void
)stopLoading;
- (
void
)refresh;
@end
|
.m
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#import "ScrollRefreshPageView.h"
#import <QuartzCore/QuartzCore.h>
#define REFRESH_HEADER_VIEW 90.f
@implementation
ScrollRefreshPageView
@synthesize
textPull = _textPull;
@synthesize
textRelease = _textRelease;
@synthesize
textLoading = _textLoading;
- (
id
)initWithFrame:(CGRect)frame
{
self
= [
super
initWithFrame:frame];
if
(
self
) {
[
self
setUpStrings];
[
self
addPullToRefreshHeader];
}
return
self
;
}
- (
void
)dealloc{
[_refreshHeaderView release];
[_refreshLabel release];
[_refreshArrow release];
[_refreshSpinner release];
[_textPull release];
[_textRelease release];
[_textLoading release];
[
super
dealloc];
}
#pragma mark -
#pragma mark Scroll view delegate
- (
void
)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
if
(_isLoading) {
return
;
}
_isDragging =
YES
;
}
- (
void
)scrollViewDidScroll:(UIScrollView *)scrollView{
if
(_isLoading) {
if
(scrollView.contentOffset.y > 0) {
self
.weiboTableView.contentInset = UIEdgeInsetsZero;
}
else
if
(scrollView.contentOffset.y >= -REFRESH_HEADER_VIEW) {
self
.weiboTableView.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, 0, 0, 0);
}
}
else
if
(_isDragging && scrollView.contentOffset.y < 0) {
[UIView animateWithDuration:0.25f animations:^{
if
(scrollView.contentOffset.y < -REFRESH_HEADER_VIEW) {
_refreshLabel.text =
self
.textRelease;
[_refreshArrow layer].transform = CATransform3DMakeRotation(M_PI, 0, 0, 1);
}
else
{
_refreshLabel.text =
self
.textPull;
[_refreshArrow layer].transform = CATransform3DMakeRotation(M_PI * 2, 0, 0, 1);
}
}];
}
}
- (
void
)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(
BOOL
)decelerate{
if
(_isLoading) {
return
;
}
_isDragging =
NO
;
if
(scrollView.contentOffset.y <= -REFRESH_HEADER_VIEW) {
[
self
startLoading];
}
}
#pragma mark -
#pragma mark Pull to refresh methods
- (
void
)setUpStrings{
_textPull = [[
NSString
alloc]initWithString:@
"拖动获取更多。。。"
];
_textRelease = [[
NSString
alloc]initWithString:@
"释放获取更多。。。"
];
_textRelease = [[
NSString
alloc]initWithString:@
"加载中。。。"
];
}
- (
void
)addPullToRefreshHeader{
CGRect mainBounds = [[UIScreen mainScreen] bounds];
_refreshHeaderView = [[UIView alloc]initWithFrame:CGRectMake(0, 0 - REFRESH_HEADER_VIEW, mainBounds.size.width, REFRESH_HEADER_VIEW)];
_refreshHeaderView.backgroundColor = [UIColor clearColor];
_refreshLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, mainBounds.size.width, REFRESH_HEADER_VIEW)];
_refreshLabel.backgroundColor = [UIColor clearColor];
_refreshLabel.font = [UIFont boldSystemFontOfSize:12.f];
_refreshLabel.textAlignment = UITextAlignmentCenter;
_refreshArrow = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@
"arrow.png"
]];
_refreshArrow.frame = CGRectMake(floorf((REFRESH_HEADER_VIEW - 20) / 2), floorf((REFRESH_HEADER_VIEW - 20) / 2), 27, 44);
_refreshSpinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
_refreshSpinner.frame = CGRectMake(floorf((REFRESH_HEADER_VIEW - 20) / 2), floorf((REFRESH_HEADER_VIEW - 20) / 2), 27, 44);
_refreshSpinner.hidesWhenStopped =
YES
;
[_refreshHeaderView addSubview:_refreshLabel];
[_refreshHeaderView addSubview:_refreshArrow];
[_refreshHeaderView addSubview:_refreshSpinner];
[
self
.weiboTableView addSubview:_refreshHeaderView];
}
- (
void
)startLoading{
_isLoading =
YES
;
[UIView animateWithDuration:0.3f animations:^{
self
.weiboTableView.contentInset = UIEdgeInsetsMake(REFRESH_HEADER_VIEW, 0, 0, 0);
_refreshLabel.text =
self
.textLoading;
_refreshArrow.hidden =
YES
;
[_refreshSpinner startAnimating];
}];
[
self
refresh];
}
- (
void
)stopLoadingComplete {
// Reset the header
_refreshLabel.text =
self
.textPull;
_refreshArrow.hidden =
NO
;
[_refreshSpinner stopAnimating];
}
- (
void
)stopLoading{
_isLoading =
NO
;
[UIView animateWithDuration:0.3f animations:^{
self
.weiboTableView.contentInset = UIEdgeInsetsZero;
[_refreshArrow layer].transform = CATransform3DMakeRotation(M_PI * 2, 0, 0, 1);
}
completion:^(
BOOL
finished){
[
self
performSelector:
@selector
(stopLoadingComplete)];
}];
}
- (
void
)refresh{
[
self
performSelector:
@selector
(stopLoading) withObject:
nil
afterDelay:5.f];
}
@end
|
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本文转自张昺华-sky博客园博客，原文链接：http://www.cnblogs.com/sunshine-anycall/archive/2012/07/15/2592663.html
，如需转载请自行联系原作者
