NSTextAttachment 自定义后的循环引用问题

NSTextAttachment的封装类

#import "DDAutoFitTextAttachment.h"

@implementation DDAutoFitTextAttachment


/**
 重载此方法 使得图片的大小和行高是一样的。

 @param textContainer textContainer
 @param lineFrag lineFrag
 @param position position
 @param charIndex charIndex
 @return attachmentBounds
 */
- (CGRect)attachmentBoundsForTextContainer:(NSTextContainer *)textContainer proposedLineFragment:(CGRect)lineFrag glyphPosition:(CGPoint)position characterIndex:(NSUInteger)charIndex
{
    return CGRectMake(0, -3, lineFrag.size.height, lineFrag.size.height);
}

@end

NSAttributedString的分类

#import "NSAttributedString+DDLabel.h"
#import "DDAutoFitTextAttachment.h"

@implementation NSAttributedString (DDLabel)

- (instancetype)initWithTitle:(NSString *)title
                    titleFont:(UIFont *)titleFont
                   titleColor:(UIColor *)titleColor
                        image:(UIImage *)image
                imagePosition:(DDAttributedStringImagePosition)imagePosition
{
    
    NSMutableAttributedString *superAttrStr = [[NSMutableAttributedString alloc]
                                        initWithString:title
                                        attributes:
                                        @{NSFontAttributeName: titleFont,
                                          NSForegroundColorAttributeName: titleColor}];
    
    DDAutoFitTextAttachment *imageAttachment = [[DDAutoFitTextAttachment alloc] init];
    imageAttachment.image = image;
    NSAttributedString *imageAttStr = [NSAttributedString attributedStringWithAttachment:imageAttachment];
    
    switch (imagePosition) {
        case DDAttributedStringImagePositionLeft:
        {
            [superAttrStr insertAttributedString:imageAttStr atIndex:0];
        }
            break;
        case DDAttributedStringImagePositionMiddle:
        {
            NSAssert(imagePosition != DDAttributedStringImagePositionMiddle , @"图片不能设置为 DDAttributedStringImagePositionMiddle");
         }
            break;
        case DDAttributedStringImagePositionRight:
        {
            [superAttrStr insertAttributedString:imageAttStr atIndex: superAttrStr.length];
         }
            break;
    }
    
    return superAttrStr.copy;
}