iOS开发 根据高度计算字符串的高度

记录一下

- (CGFloat)calculateHeight:(NSString *)string Width:(CGFloat)width fontSize:(CGFloat)fontSize {
    CGSize size = CGSizeMake(width, MAXFLOAT);
    NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
    [style setLineSpacing:10];
    NSDictionary *dic = @{NSFontAttributeName:[UIFont systemFontOfSize:fontSize], NSParagraphStyleAttributeName:style};
    CGFloat height = [string boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading attributes:dic context:nil].size.height;
    return height;
}