UILabel高度计算

1.单行文本高度计算

define VPTEXTSIZE(text, font) [text length] > 0 ? [text \

sizeWithAttributes:@{NSFontAttributeName:font}] : CGSizeZero

2.默认不设置行间距时，单行多行都可以

• (CGSize)heightWithFont:(UIFont *)font
  MaxWidth:(float)width{
  if (self.length==0) {
  return CGSizeMake(0, 0);
  }
  CGRect rect = [self boundingRectWithSize:CGSizeMake(width, MAXFLOAT)
  options:NSStringDrawingTruncatesLastVisibleLine |
  NSStringDrawingUsesLineFragmentOrigin|
  NSStringDrawingUsesFontLeading
  attributes:@{NSFontAttributeName:font}
  context:nil];

  return CGSizeMake((rect.size.width), (rect.size.height));

}
2.设置行间距的情况
多行的情况
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = 12;
NSDictionary *dic = @{NSParagraphStyleAttributeName:paragraphStyle,NSFontAttributeName:[UIFont systemFontOfSize:14]};
NSMutableAttributedString *attrString = [[NSMutableAttributedString alloc] initWithString:text attributes:dic];
text4.attributedText = attrString;

• (CGFloat)heightWithStringAttribute:(NSDictionary *)attribute fixedWidth:(CGFloat)width {

  NSParameterAssert(attribute);

  CGFloat height = 0;

  if (self.length) {

    CGRect rect = [self boundingRectWithSize:CGSizeMake(width, MAXFLOAT)
                                     options:NSStringDrawingTruncatesLastVisibleLine |NSStringDrawingUsesLineFragmentOrigin |
                   NSStringDrawingUsesFontLeading
                                  attributes:attribute
                                     context:nil];
    
    height = rect.size.height;
  

  }

  return height;
  }
  当文本为单行时候又设置了行间距(纯英文的情况没有问题)，但是包含有中文的时候计算的高度就会有问题

height=[text heightWithStringAttribute:dic1 fixedWidth:[UIScreen mainScreen].bounds.size.width-20*2];
if ((height - [UIFont systemFontOfSize:14].lineHeight) <= paragraphStyle.lineSpacing) {//是否是单行
if ([self containChinese:text]) { //如果包含中文
height = height-paragraphStyle.lineSpacing;
// height = [NSString aLineOfTextHeightWithStringAttribute:dic1];

    }
    tex5.text=text;  //单行的情况就不能设置为attributedText了
}else{
    tex5.attributedText = attrString;

}

• (CGFloat)aLineOfTextHeightWithStringAttribute:(NSDictionary *)attribute {

  CGFloat height = 0;
  CGRect rect = [@"One" boundingRectWithSize:CGSizeMake(200, MAXFLOAT)
  options:NSStringDrawingTruncatesLastVisibleLine |NSStringDrawingUsesLineFragmentOrigin |
  NSStringDrawingUsesFontLeading
  attributes:attribute
  context:nil];

  height = rect.size.height;
  return height;
  }