设置label文字顶格显示

• (void)setTextTop
  {
  NSMutableString *resultStr = [self.text mutableCopy];
  NSArray *array = [resultStr componentsSeparatedByString:@"\n"];
  NSInteger temp = 0;
  NSInteger lines = self.lineBreakMode;
  for (int j = 0; j < array.count; j++) {
  NSString *str = array[j];

    if ([str isEqual:@""]) {
        temp --;
    }
    if (str.length > self.width - 40) {
        temp++;
    }
  

  }

  for (int i = 0; i < (lines - array.count - temp + 1); i++) {
  [resultStr appendString:@"\n"];
  }
  self.text = resultStr;
  }

以下两个没试过：

• (void)alignTop {
  CGSize fontSize = [self.text sizeWithFont:self.font];
  double finalHeight = fontSize.height * self.numberOfLines;
  double finalWidth = self.frame.size.width; //expected width of label
  CGSize theStringSize = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(finalWidth, finalHeight) lineBreakMode:self.lineBreakMode];
  int newLinesToPad = (finalHeight - theStringSize.height) / fontSize.height;
  for(int i=0; i<newLinesToPad; i++)
  self.text = [self.text stringByAppendingString:@"\n "];
  }

• (void)alignBottom {
  CGSize fontSize = [self.text sizeWithFont:self.font];
  double finalHeight = fontSize.height * self.numberOfLines;
  double finalWidth = self.frame.size.width; //expected width of label
  CGSize theStringSize = [self.text sizeWithFont:self.font constrainedToSize:CGSizeMake(finalWidth, finalHeight) lineBreakMode:self.lineBreakMode];
  int newLinesToPad = (finalHeight - theStringSize.height) / fontSize.height;
  for(int i=0; i<newLinesToPad; i++)
  self.text = [NSString stringWithFormat:@" \n%@",self.text];
  }