下拉刷新对象RefreshObject

下拉刷新对象RefreshObject

效果

说明

1. 分离了动画实现与刷新逻辑

2. 你可以根据自己的需要，设计自己的动画效果，你的动画只需要继承协议，实现协议里面的方法即可

3. 本设计方案是用的组件方式，代码复用率很高，灵活性很强

源码

https://github.com/YouXianMing/RefreshObject

//
//  RefreshObjectAnimationProtocal.h
//  TableViewRefresh
//
//  Created by YouXianMing on 15/6/25.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//
 
#import <Foundation/Foundation.h>
 
@protocol RefreshObjectAnimationProtocal <NSObject>
 
@required
- (void)animationWithPercent:(CGFloat)percent;
- (void)startRefreshAnimation;
- (void)endRefreshAnimation;
 
@end

//
//  RefreshObject.h
//  UIScrollView
//
//  Created by YouXianMing on 15/6/24.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//
 
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
@class RefreshObject;
 
typedef enum : NSUInteger {
 
    NORMAL_STATE,  // 正常状态
    REFRESH_STATE, // 刷新状态
 
} ERefreshState;
 
@protocol RefreshObjectDelegate <NSObject>
 
@required
/**
 *  开始刷新
 *
 *  @param refreshObject
 */
- (void)startRefreshing:(RefreshObject *)refreshObject;
 
/**
 *  结束刷新
 *
 *  @param refreshObject
 */
- (void)endRefresh:(RefreshObject *)refreshObject;
 
- (void)moving:(RefreshObject *)refreshObject offset:(CGFloat)offset percent:(CGFloat)percent;
 
@end
 
@interface RefreshObject : NSObject
 
/**
 *  代理
 */
@property (nonatomic, weak)     id <RefreshObjectDelegate> delegate;
 
/**
 *  当前状态
 */
@property (nonatomic, readonly) ERefreshState    state;
@property (nonatomic)           CGFloat          height;
@property (nonatomic, weak)     UIScrollView    *scrollView;
 
/**
 *  === 子类可以重写该方法实现新的刷新效果 ===
 *
 *  开始刷新
 */
- (void)beginRefreshing;
 
/**
 *  === 子类可以重写该方法实现新的刷新效果 ===
 *
 *  结束刷新
 */
- (void)endRefresh;
 
@end

//
//  RefreshObject.m
//  UIScrollView
//
//  Created by YouXianMing on 15/6/24.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//
 
#import "RefreshObject.h"
 
@interface RefreshObject ()
 
@end
 
@implementation RefreshObject
 
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
 
    // 当前位置
    float currentPostion = _scrollView.contentOffset.y;
 
    if (_scrollView.isDragging) {
        // 拖拽中
 
        if (_state == NORMAL_STATE) {
 
            // 获取位移的信息
            if (_delegate) {
 
                CGFloat percent = ;
                if (currentPostion <= ) {
                    percent = -currentPostion / _height;
                }
 
                [_delegate moving:self offset:currentPostion percent:percent];
            }
        }
 
    } else {
        // 停止拖拽
 
        if (currentPostion < -_height) {
 
            [self beginRefreshing];
        }
    }
 
}
 
- (void)beginRefreshing {
 
    if (_state == NORMAL_STATE) {
        _state = REFRESH_STATE;
 
        if (_delegate) {
            [_delegate startRefreshing:self];
        }
 
        [UIView animateWithDuration:0.3 animations:^{
            _scrollView.contentInset = UIEdgeInsetsMake(_height, , , );
        } completion:^(BOOL finished) {
 
        }];
    }
}
 
- (void)endRefresh {
 
    if (_delegate) {
        [_delegate endRefresh:self];
    }
 
    [UIView animateWithDuration:0.3f animations:^{
        _scrollView.contentInset = UIEdgeInsetsMake(, , , );
    } completion:^(BOOL finished) {
        _state = NORMAL_STATE;
    }];
}
 
@end

//
//  UIScrollView+RefreshObject.h
//  UIScrollView
//
//  Created by YouXianMing on 15/6/24.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//
 
#import <UIKit/UIKit.h>
#import "RefreshObject.h"
 
@interface UIScrollView (RefreshObject)
 
/**
 *  需要主动赋值
 */
@property (nonatomic, strong)  RefreshObject  *refreshObject;
 
/**
 *  添加观察者
 */
- (void)addObserver;
 
/**
 *  移除观察者
 */
- (void)removeObserver;
 
@end

//
//  UIScrollView+RefreshObject.m
//  UIScrollView
//
//  Created by YouXianMing on 15/6/24.
//  Copyright (c) 2015年 YouXianMing. All rights reserved.
//
 
#import "UIScrollView+RefreshObject.h"
#import <objc/runtime.h>
 
@implementation UIScrollView (RefreshObject)
 
#pragma mark - 添加属性
 
@dynamic refreshObject;
 
NSString * const _recognizerRefreshObject = @"recognizerRefreshObject";
 
- (void)setRefreshObject:(RefreshObject *)refreshObject {
 
    objc_setAssociatedObject(self, (__bridge const void *)(_recognizerRefreshObject), refreshObject, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}
 
- (RefreshObject *)refreshObject {
 
    return objc_getAssociatedObject(self, (__bridge const void *)(_recognizerRefreshObject));
}
 
#pragma mark -
 
- (void)addObserver {
 
    if (self.refreshObject && self.refreshObject.scrollView == nil) {
 
        // 获取scrollView
        self.refreshObject.scrollView = self;
 
        // 添加监听
        [self addObserver:self.refreshObject
               forKeyPath:@"contentOffset"
                  options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld
                  context:nil];
    }
}
 
- (void)removeObserver {
 
    if (self.refreshObject) {
 
        // 移除监听
        [self removeObserver:self.refreshObject
                  forKeyPath:@"contentOffset"];
 
        self.refreshObject.scrollView = nil;
        self.refreshObject            = nil;
    }
}
 
@end

细节

继承协议 RefreshObjectAnimationProtocal 并实现协议方法即可，使用的话，如下所示