Label设置行间距及带行间距计算高度

1.给UILabel设置行间距和字间距

//行间距
#define UILABEL_LINE_SPACE 3

-(void)setLabelSpace:(UILabel*)label withValue:(NSString*)str withFont:(UIFont*)font {
    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;
}

2.计算UILabel的高度(带有行间距的情况)

-(CGFloat)getSpaceLabelHeight:(NSString*)str withFont:(UIFont*)font withWidth:(CGFloat)width {
    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, screenHeight) options:NSStringDrawingUsesLineFragmentOrigin attributes:dic context:nil].size;
    return size.height;
}