iOS开发UILabel多行文本设置行间距

[tempLabel setFrame:CGRectMake(0, 0, 304, 0)];
UIFont *font = [UIFont fontWithName:kFontName_Content size:15]; //这里的字体名是自定义的宏
NSString *str = [_messageDetailDic objectForKey:@"content"]; //从字典里取出文本内容
[tempLabel setNumberOfLines:0];
[tempLabel setFont:font];
NSMutableAttributedString *attStr = [[NSMutableAttributedString alloc] initWithString:str];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
[paragraphStyle setLineSpacing:7]; //行高
[attStr addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [str length])];
tempLabel.attributedText = attStr;
[tempLabel sizeToFit];