add Bottom Line

UIView+EX.h

#import <UIKit/UIKit.h>

@interface UIView (EX)

@property (nonatomic, strong)  UIView  *bottomLine; // <##>

- (void)as_addBottomLine;

- (void)as_addBottomLineWithLeftOffset:(CGFloat)leftOffset rightOffset:(CGFloat)rightOffset;

@end

UIView+EX.m

#import "UIView+EX.h"
#import <objc/runtime.h>

@implementation UIView (EX)

- (UIView *)bottomLine {
    return objc_getAssociatedObject(self, _cmd);
}

- (void)setBottomLine:(UIView *)bottomLine {
    objc_setAssociatedObject(self, @selector(bottomLine), bottomLine, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (void)as_addBottomLine {
    [self as_addBottomLineWithLeftOffset:0 rightOffset:0];
}

- (void)as_addBottomLineWithLeftOffset:(CGFloat)leftOffset rightOffset:(CGFloat)rightOffset {
    if (!self.bottomLine) {
        UIView *line = [UIView new];
        line.backgroundColor = [UIColor yd_grey_dddddd];
        [self addSubview:line];
        self.bottomLine = line;
    }

    [self.bottomLine mas_remakeConstraints:^(MASConstraintMaker *make) {
        make.left.right.bottom.mas_equalTo(self).insets(UIEdgeInsetsMake(0, leftOffset, 0, rightOffset));
        make.height.mas_equalTo(0.5);
    }];
}
@end