UILabel设置行间距

UILabel设置行间距需要使用属性字符串的方法
其中主要的一段代码是:

NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init];
    paraStyle.lineBreakMode = NSLineBreakByCharWrapping;
    paraStyle.alignment = NSTextAlignmentLeft;
    paraStyle.lineSpacing = UILABEL_LINE_SPACE; //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:str attributes:dic];
    label.attributedText = attributeStr;

当你需要计算Label的高度的时候，同样把行间距属性加进去就可以了

NSMutableParagraphStyle *paraStyle = [[NSMutableParagraphStyle alloc] init];
    paraStyle.lineBreakMode = NSLineBreakByCharWrapping;
    paraStyle.alignment = NSTextAlignmentLeft;
    paraStyle.lineSpacing = UILABEL_LINE_SPACE;
    paraStyle.hyphenationFactor = 1.0;
    paraStyle.firstLineHeadIndent = 0.0;
    paraStyle.paragraphSpacingBefore = 0.0;
    paraStyle.headIndent = 0;
    paraStyle.tailIndent = 0;
    NSDictionary *dic = @{NSFontAttributeName:font, NSParagraphStyleAttributeName:paraStyle, NSKernAttributeName:@1.5f};
    
    CGSize size = [str boundingRectWithSize:CGSizeMake(width, HEIGHT) options:NSStringDrawingTruncatesLastVisibleLine |
                   NSStringDrawingUsesLineFragmentOrigin |
                   NSStringDrawingUsesFontLeading attributes:dic context:nil].size;
    return size.height;