封装UITableView 索引视图

雨点打透心脏的1/2处 2022-03-22 03:40 216阅读 0赞

由于UITableView的索引视图的定制性太差，所以自己封装了一个简单的索引试图。

1.把索引的内容，使用Label布局好

- (void)reloadIndex {
        NSArray<NSString *> *titles = [self.delegate titlesOfIndexView:self];
        [self.contentView.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];
        NSMutableArray<UILabel *> *titleLabels = [NSMutableArray array];
        CGSize labelSize = CGSizeMake(self.frame.size.width, 24);
        self.contentView.frame =CGRectMake(0, 0,self.frame.size.width, labelSize.height*titles.count);
        self.contentView.center = CGPointMake(self.bounds.size.width/2, self.bounds.size.height/2);
        for (int i = 0; i < titles.count; i++) {
            UILabel *titleLabel = [UILabel new];
            titleLabel.font = [UIFont systemFontOfSize:10];
            titleLabel.textColor = [UIColor redColor];
            titleLabel.textAlignment = NSTextAlignmentCenter;
            titleLabel.text = titles[i];
            [self.contentView addSubview:titleLabel];
            [titleLabels addObject:titleLabel];
            [titleLabel setFrame:CGRectMake(0, i*labelSize.height, labelSize.width, labelSize.height)];
        }
        _titleLabels = titleLabels;
        _selectedIndex = -1;
    }

2.根据点击事件和点击移动事件去处理和触发选中的序号

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
        [self calculatePoint:[touches.anyObject locationInView:self]];
    }
    
    - (void)touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
        [self calculatePoint:[touches.anyObject locationInView:self]];
    }
    
    - (void)calculatePoint:(CGPoint)point {
        CGFloat y = point.y;
        __block NSInteger index = 0;
        if (y > self.contentView.frame.origin.y && y < CGRectGetMaxY(self.contentView.frame)) {
            [self.titleLabels enumerateObjectsUsingBlock:^(UILabel * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
                CGRect frame = obj.frame;
                CGRect rect = [self.contentView convertRect:frame toView:self];
                if (CGRectContainsPoint(rect, point)) {
                    index = idx;
                    *stop = YES;
                } 
            }];
        }else if (y >= CGRectGetMaxY(self.contentView.frame)) {
            index = self.titleLabels.count - 1;
        }
        if ([self.delegate respondsToSelector:@selector(indexView:didSelectIndex:)]) {
            if (index == self.selectedIndex) {
                return;
            }
            self.selectedIndex = index;
            if (@available(iOS 10.0, *)) {
                UIImpactFeedbackGenerator *impact = [[UIImpactFeedbackGenerator alloc] initWithStyle:UIImpactFeedbackStyleMedium];
                [impact impactOccurred];
            } else {
    
            }
            [self.delegate indexView:self didSelectIndex:index];
        }
    }

[Demo源码][Demo]

[Demo]: https://download.csdn.net/download/liuyinghui523/10938515