Label随文字内容多少高度自适应

1.第一种
demo

#pragma mark 给UILabel设置行间距和字间距等属性
+(NSAttributedString *)setAttributesWithLabel:(UILabel*)label withText:(NSString*)text withFont:(UIFont*)font{
    NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init];
    paraStyle.lineBreakMode = NSLineBreakByCharWrapping;
    paraStyle.alignment = NSTextAlignmentCenter;
    paraStyle.lineSpacing = 1; //设置行间距
    paraStyle.hyphenationFactor = 1.0;
    paraStyle.firstLineHeadIndent = 0.0;
    paraStyle.paragraphSpacingBefore = 0.0;
    paraStyle.headIndent = 0;
    paraStyle.tailIndent = 0;
    //设置字间距 NSKernAttributeName:@1.5f
    NSDictionary *dic = @{NSFontAttributeName:font, NSParagraphStyleAttributeName:paraStyle, NSKernAttributeName:@1.5f
                          };
    
    NSAttributedString *attributeStr = [[NSAttributedString alloc] initWithString:text attributes:dic];
    label.attributedText = attributeStr;
    return label.attributedText;
}
#pragma mark 文字不同大小
+(NSAttributedString *)setSpecialAttributesWithLabel:(UILabel*)label withTipLength:(NSInteger)length withText:(NSString*)text withFontTip:(UIFont*)fontTip withFont:(UIFont*)font withColor:(UIColor *)color{
    NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init];
    paraStyle.lineBreakMode = NSLineBreakByCharWrapping;
    paraStyle.alignment = NSTextAlignmentCenter;
    paraStyle.lineSpacing = 1; //设置行间距
    paraStyle.hyphenationFactor = 1.0;
    paraStyle.firstLineHeadIndent = 0.0;
    paraStyle.paragraphSpacingBefore = 0.0;
    paraStyle.headIndent = 0;
    paraStyle.tailIndent = 0;
    //设置字间距 NSKernAttributeName:@1.5f
    NSMutableAttributedString* rate = [[NSMutableAttributedString alloc] initWithString:text];
    [rate addAttribute:NSFontAttributeName value:fontTip range:NSMakeRange(0,  length)];
    [rate addAttribute:NSFontAttributeName value:font range:NSMakeRange(length,  text.length-length)];
    [rate addAttribute:NSForegroundColorAttributeName value:color range:NSMakeRange(length,  text.length-length)];
    
    [rate addAttribute:NSParagraphStyleAttributeName value:paraStyle range:NSMakeRange(0,  text.length)];
    [rate addAttribute:NSKernAttributeName value:@1.5f range:NSMakeRange(0,  text.length)];
    label.attributedText = rate;
    return label.attributedText;
}
#pragma mark 计算UILabel的高度(先设置属性，再根据返回的NSAttributedString计算高度)
+(CGFloat)getLabelHeightWithAttributedString:(NSAttributedString*)attributedString withWidth:(CGFloat)width{
    
    CGRect rect = [attributedString boundingRectWithSize:CGSizeMake(width, kScreenHeight) options:NSStringDrawingUsesLineFragmentOrigin context:nil];
    return rect.size.height;
}

2.第二种:NSString的分类

/**
 根据字体、行数、行间距和constrainedWidth计算文本占据的size
 **/
- (CGSize)textSizeWithFont:(UIFont*)font
             numberOfLines:(NSInteger)numberOfLines
               lineSpacing:(CGFloat)lineSpacing
          constrainedWidth:(CGFloat)constrainedWidth{
    
    if (self.length == 0) {
        return CGSizeZero;
    }
    CGFloat oneLineHeight = font.lineHeight;
    CGSize textSize = [self boundingRectWithSize:CGSizeMake(constrainedWidth, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:font} context:nil].size;
    //  行数
    CGFloat rows = textSize.height / oneLineHeight;
    CGFloat realHeight = oneLineHeight;
    // 0 不限制行数，真实高度加上行间距
    if (numberOfLines == 0) {
        if (rows >= 1) {
            realHeight = (rows * oneLineHeight) + (rows - 1) * lineSpacing;
        }
    } else {
        //  行数超过指定行数的时候，限制行数
        if (rows > numberOfLines) {
            rows = numberOfLines;
                }
        realHeight = (rows * oneLineHeight) + (rows - 1) * lineSpacing;
    }
    //  返回真实的宽高
    return CGSizeMake(constrainedWidth, realHeight);
}

- (CGSize)textSizeWithFont:(UIFont*)font
             numberOfLines:(NSInteger)numberOfLines
          constrainedWidth:(CGFloat)constrainedWidth{
    
    if (self.length == 0) {
        return CGSizeZero;
    }
    CGFloat oneLineHeight = font.lineHeight;
    CGSize textSize = [self boundingRectWithSize:CGSizeMake(constrainedWidth, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:font} context:nil].size;
    //  行数
    CGFloat rows = textSize.height / oneLineHeight;
    CGFloat realHeight = oneLineHeight;
    // 0 不限制行数，真实高度加上行间距
    if (numberOfLines == 0) {
        if (rows >= 1) {
            realHeight = (rows * oneLineHeight) + (rows - 1) ;
        }
    } else {
        //  行数超过指定行数的时候，限制行数
        if (rows > numberOfLines) {
            rows = numberOfLines;
        }
        realHeight = (rows * oneLineHeight) + (rows - 1) ;
    }
    //  返回真实的宽高
    return CGSizeMake(constrainedWidth, realHeight);
}

/// 计算字符串长度（一行时候）
- (CGSize)textSizeWithFont:(UIFont*)font
                limitWidth:(CGFloat)maxWidth {
    CGSize size = [self boundingRectWithSize:CGSizeMake(MAXFLOAT, 36)options:(NSStringDrawingTruncatesLastVisibleLine | NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading)  attributes:@{ NSFontAttributeName : font} context:nil].size;
    size.width = size.width > maxWidth ? maxWidth : size.width;
    size.width = ceil(size.width);
    size.height = ceil(size.height);
    return size;
}

- (CGSize)textSizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size lineBreakMode:(NSLineBreakMode)lineBreakMode {
    CGSize textSize;
    if (CGSizeEqualToSize(size, CGSizeZero)) {
        NSDictionary *attributes = [NSDictionary dictionaryWithObject:font forKey:NSFontAttributeName];
        textSize = [self sizeWithAttributes:attributes];
    } else {
        textSize = [self sizeWithFont:font constrainedToSize:size lineBreakMode:NSLineBreakByCharWrapping];
    }
    return textSize;
}