下拉刷新效果图
2d8378308241886d851cc34098d05490.gif
代码结构
// XDRefreshView.h
// XDRefreshView.m
// XDRefreshView.h
// 下拉刷新－自定义
//
// Created by 窦心东 on 16/9/24.
// Copyright © 2016年 窦心东. All rights reserved.
//
#import <UIKit/UIKit.h>
@interface XDRefreshView : UIView
@property (nonatomic ,copy) void(^refreshBlock)();
//结束刷新
- (void)endRefreshing;
@end
//
// XDRefreshView.m
// 下拉刷新－自定义
//
// Created by 窦心东 on 16/9/24.
// Copyright © 2016年 窦心东. All rights reserved.
//
#import "XDRefreshView.h"
#define XDRefreshViewHeight 60
//三种状态
typedef enum{
XDRefreshViewStatusNormol, //正常状态
XDRefreshViewStatusPuling, //释放刷新状态
XDRefreshViewStatusRefreshing //正在刷新状态
} XDRefreshViewStatus;
@interface XDRefreshView ()
//图片
@property (nonatomic,strong) UIImageView *imageView;
//文字
@property (nonatomic,strong) UILabel *label;
//记录当前状态
@property (nonatomic,assign) XDRefreshViewStatus currenStatus;
//记录父控件，可以滚动的
@property (nonatomic,strong) UIScrollView *superScrollView;
//吃包子动画图片数组
@property (nonatomic,strong) NSArray *refreshImages;
@end
@implementation XDRefreshView
//添加子控件
-(instancetype)initWithFrame:(CGRect)frame{
if (self=[super initWithFrame:frame]) {
[self addSubview:self.imageView];
[self addSubview:self.label];
//设置frame
self.imageView.frame = CGRectMake(80, 0, 50, 50);
self.label.frame = CGRectMake(130, 20, 300, 20);
}
return self;
}
//监听父控件的滚动
//当控件加到父控件（tableview）时调用此方法
-(void)willMoveToSuperview:(UIView *)newSuperview{
[super willMoveToSuperview:newSuperview];
// NSLog(@"控件加到父控件是%@",newSuperview);//获取到父控件
//父控件就是我们要监听滚动事件的父控件了
//只有父控件能滚动的才能去监听
if ([newSuperview isKindOfClass:[UIScrollView class]]) {
self.superScrollView = (UIScrollView *)newSuperview;
//监听父控件的滚动
//当我们一直拖动tableView的时候scrollView有一个属性一直变化
//所以说监听父控件的滚动就是监听 self.superScrollView对象的contentOffset的属性的改变
//ios中用于监听对象属性的机制叫做KVO
// KVO： Key-Value-observing 键值监听
//键值监听KVO作用：就是监听对象一个属性的改变
// KVO使用：我们要监听那个对象，就用哪个对象去调方法
//当监听对象身上的这种属性发生变化时会［（addObserver）调用这个（forKeyPath:options:context:）方法］
//注意⚠️使用KVO的时候，像使用通知一样需要用完取消在dealloc方法中
[self.superScrollView addObserver:self forKeyPath:@"contentOffset" options:0 context:nil];
}
}
#pragma mark - KVO时 当监听对象身上的这种属性发生变化时会调 用这个方法
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context{
// NSLog(@"自己监听到父控件的滚动Y值：%f",self.superScrollView.contentOffset.y);
//根据拖动的程度不同，来切换状态
if (self.superScrollView.isDragging) {
//手拖动normol->puling，puling->normol
CGFloat normolPulingOffset = -124;
if (self.currenStatus ==XDRefreshViewStatusPuling && self.superScrollView.contentOffset.y>normolPulingOffset) {
// NSLog(@"切换到Normol");
self.currenStatus = XDRefreshViewStatusNormol;
}else if (self.currenStatus ==XDRefreshViewStatusNormol && self.superScrollView.contentOffset.y<=normolPulingOffset){
// NSLog(@"切换到Puling");
self.currenStatus = XDRefreshViewStatusPuling;
}
}else{
//手松开puling->refreshing
if (self.currenStatus ==XDRefreshViewStatusPuling) {
// NSLog(@"切换到Refreshing");
self.currenStatus = XDRefreshViewStatusRefreshing;
}
}
}
#pragma mark - 当切换状态时必经此方法getter
- (void)setCurrenStatus:(XDRefreshViewStatus)currenStatus{
_currenStatus = currenStatus;
switch (_currenStatus) {
case XDRefreshViewStatusNormol:
{
NSLog(@"切换到Normol");
//动画停下来
[self.imageView stopAnimating];
self.label.text = @"下拉刷新，再往下拖一点点";
self.imageView.image = [UIImage imageNamed:@"normal"];
}
break;
case XDRefreshViewStatusPuling:
{
NSLog(@"切换到Puling");
self.label.text = @"释放我就可以刷新啦～～";
self.imageView.image = [UIImage imageNamed:@"pulling"];
}
break;
case XDRefreshViewStatusRefreshing:
{
NSLog(@"切换到Refreshing");
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"MM-dd-YY HH:mm"];
NSString *timestamp = [formatter stringFromDate:[NSDate date]];
self.label.text = [NSString stringWithFormat:@"数据最后更新时间%@",timestamp];
// @"正在刷新数据哟......";
self.imageView.animationImages = self.refreshImages;
//播多长时间
self.imageView.animationDuration = 0.1 * self.refreshImages.count;
//开始播放
[self.imageView startAnimating];
//tableView往下走一点
[UIView animateWithDuration:0.25 animations:^{
self.superScrollView.contentInset = UIEdgeInsetsMake(self.superScrollView.contentInset.top+XDRefreshViewHeight, self.superScrollView.contentInset.left, self.superScrollView.contentInset.bottom, self.superScrollView.contentInset.right);
}];
//让控制器做事情
// Block使用1.定义block 2.传递block3.调用block
//3调用block 时先判断block是否有值，没有的话是会崩溃的
if (self.refreshBlock) {
self.refreshBlock();
}
}
break;
default:
break;
}
}
//结束刷新
- (void)endRefreshing{
//refreshing->normol
if (_currenStatus == XDRefreshViewStatusRefreshing) {
self.currenStatus = XDRefreshViewStatusNormol;
//tableView要回去
[UIView animateWithDuration:0.25 animations:^{
self.superScrollView.contentInset = UIEdgeInsetsMake(self.superScrollView.contentInset.top-XDRefreshViewHeight, self.superScrollView.contentInset.left, self.superScrollView.contentInset.bottom, self.superScrollView.contentInset.right);
}];
}
}
#pragma mark - deallco
-(void)dealloc{
[self.superScrollView removeObserver:self forKeyPath:@"contentOffset" context:nil];
}
#pragma mark - 懒加载
-(UIImageView *)imageView{
if (_imageView==nil) {
UIImage *image = [UIImage imageNamed:@"normal"];
_imageView = [[UIImageView alloc] initWithImage:image];
}
return _imageView;
}
-(UILabel *)label{
if (_label == nil) {
_label = [[UILabel alloc] init];
//设置
_label.textColor = [UIColor darkGrayColor];
_label.font = [UIFont systemFontOfSize:16];
_label.text = @"下拉刷新";
}
return _label;
}
-(NSArray *)refreshImages{
if (_refreshImages==nil) {
NSMutableArray *arrayM = [NSMutableArray array];
for (int i=1; i<4; i++) {
NSString *imagesName = [NSString stringWithFormat:@"refreshing_0%d",i];
UIImage *image = [UIImage imageNamed:imagesName];
[arrayM addObject:image];
}
_refreshImages = arrayM;
}
return _refreshImages;
}
@end
// XDRefreshTableViewController.h
// XDRefreshTableViewController.m
//
// XDRefreshTableViewController.h
// 下拉刷新－自定义
//
// Created by 窦心东 on 16/9/24.
// Copyright © 2016年 窦心东. All rights reserved.
//
#import <UIKit/UIKit.h>
@interface XDRefreshTableViewController : UITableViewController
@end
//
// XDRefreshTableViewController.m
// 下拉刷新－自定义
//
// Created by 窦心东 on 16/9/24.
// Copyright © 2016年 窦心东. All rights reserved.
//
#import "XDRefreshTableViewController.h"
#import "XDRefreshView.h"
@interface XDRefreshTableViewController ()
//要显示的数据
@property (nonatomic,strong) NSArray *cities;
@property (nonatomic,strong) XDRefreshView *refreahView;
@end
@implementation XDRefreshTableViewController
/**
* 创建下拉刷新控件
*/
-(XDRefreshView *)refreahView{
if (_refreahView==nil) {
_refreahView = [[XDRefreshView alloc] initWithFrame:CGRectMake(0,-60, [UIScreen mainScreen].bounds.size.width, 60)];
// _refreahView.backgroundColor = [UIColor brownColor];
}
return _refreahView;
}
- (void)viewDidLoad {
[super viewDidLoad];
/**
* 加载数据
*/
self.cities = [self loadData];
//添加刷新控件到tableView上
[self.tableView addSubview:self.refreahView];
//1定义block ： refreahView.refreshBlock
//2传递block（赋值）：refreahView.refreshBlock = ^()
self.refreahView.refreshBlock = ^(){
NSLog(@"告诉控制器进入刷新状态了");
//由于加载的是plist文件比较快，现在我们用GCD方式添加延时
ino64_t delayInSeconds = 3;
__weak XDRefreshTableViewController *weakSelf = self;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
//加载数据
NSArray *newArray = [weakSelf loadData];
NSMutableArray *newArrayM = [NSMutableArray arrayWithArray:newArray];
[newArrayM addObjectsFromArray:weakSelf.cities];
weakSelf.cities = newArrayM;
[weakSelf.tableView reloadData];
//结束刷新
[weakSelf.refreahView endRefreshing];
});
};
}
-(void)viewDidAppear:(BOOL)animated{
[super viewDidAppear:animated];
NSLog(@"self.tableView.contentInset.top（tableView的起始位置Y值） =%f",self.tableView.contentInset.top);
}
//加载数据源数据
- (NSArray *)loadData{
NSString *path = [[NSBundle mainBundle] pathForResource:@"cities" ofType:@"plist"];
NSArray *array = [NSArray arrayWithContentsOfFile:path];
return array;
}
#pragma mark - Table view data source
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return self.cities.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"reuseIdentifier" forIndexPath:indexPath];
cell.textLabel.text = self.cities[indexPath.row];
return cell;
}
@end
效果图
2d8378308241886d851cc34098d05490.gif
网友评论