新浪微博客户端(44)-分页表情键盘

DJEmotionListView.m

#import "DJEmotionListView.h"

// 单页表情显示数量
#define DJEmotionPageSize 20



@interface DJEmotionListView() <UIScrollViewDelegate>

/** Emotion 上部滑动区域 */
@property (nonatomic,weak) UIScrollView *emotionScrollView;
/** Emotion 底部pageControl */
@property (nonatomic,weak) UIPageControl *emotionPageControl;

@end


@implementation DJEmotionListView



- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        
       UIScrollView *emotionScrollView = [[UIScrollView alloc] init];
        [self addSubview:emotionScrollView];
        self.emotionScrollView = emotionScrollView;
        emotionScrollView.backgroundColor = [UIColor redColor];
        // 设置scrollView水平和垂直方向上的滚动条为空
        emotionScrollView.showsHorizontalScrollIndicator = NO;
        emotionScrollView.showsVerticalScrollIndicator = NO;
        // 设置scrollView 分页
        emotionScrollView.pagingEnabled = YES;
        emotionScrollView.delegate = self;
        
        
        UIPageControl *emotionPageControl = [[UIPageControl alloc] init];
        [self addSubview:emotionPageControl];
        self.emotionPageControl = emotionPageControl;
         emotionPageControl.backgroundColor = [UIColor blueColor];
        emotionPageControl.userInteractionEnabled = NO; // 设置pageContorl不可点击

        // 使用KVC自定义pageControl 显示图片
        [emotionPageControl setValue:[UIImage imageNamed:@"compose_keyboard_dot_normal"] forKeyPath:@"_pageImage"];
        [emotionPageControl setValue:[UIImage imageNamed:@"compose_keyboard_dot_selected"] forKeyPath:@"_currentPageImage"];
        
        
    }
    return self;
}





- (void)layoutSubviews {

    [super layoutSubviews];
    
    // emotionPageControl
    CGFloat pageControlW = self.width;
    CGFloat pageControlH = 35;
    CGFloat pageControlX = 0;
    CGFloat pageControlY = self.height - pageControlH;
    self.emotionPageControl.frame = CGRectMake(pageControlX, pageControlY, pageControlW, pageControlH);
    
    // emotionScrollView
    CGFloat scrollViewW = self.width;
    CGFloat scrollViewH = pageControlY;
    CGFloat scrollViewX = 0;
    CGFloat scrollViewY = 0;
    self.emotionScrollView.frame = CGRectMake(scrollViewX, scrollViewY, scrollViewW, scrollViewH);
    
    // pageView
    NSUInteger count = self.emotionScrollView.subviews.count;
    CGFloat pageViewW = self.emotionScrollView.width;
    CGFloat pageViewH = self.emotionScrollView.height;
    CGFloat pageViewY = self.emotionScrollView.y;
    
    for (int i = 0; i < count; i++) {
        UIView *pageView = self.emotionScrollView.subviews[i];
        pageView.x = i * pageViewW;
        pageView.y = pageViewY;
        pageView.width = pageViewW;
        pageView.height = pageViewH;
    }

    self.emotionScrollView.contentSize = CGSizeMake(scrollViewW * count, 0);

}



- (void)setEmotions:(NSArray *)emotions {

    
    _emotions = emotions;
    // emotion 总个数
    NSUInteger emotionCount = emotions.count;
    // 页码总个数
    NSUInteger pageNums = (emotionCount + DJEmotionPageSize - 1) / DJEmotionPageSize;
    
    // 更新pageControl 显示个数
    self.emotionPageControl.numberOfPages = pageNums;
    
    // 为scrollView 添加子View
    for (int i = 0; i < pageNums; i++) {
        UIView *pageView = [[UIView alloc] init];
        pageView.backgroundColor = DJRandomColor;
        [self.emotionScrollView addSubview:pageView];
    }
    
}

#pragma mark - UIScrollView 代理方法

/** 通过监听scrollView滚动来更新pageControl状态 */
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {

    double page = scrollView.contentOffset.x / scrollView.width;
    self.emotionPageControl.currentPage = (int)(page + 0.5);
    
}




@end

最终效果：