iOS开发 根据字符内容计算宽高度

根据内容计算宽度

- (CGFloat)calculateRowWidth:(NSString *)string {
    NSDictionary *dic = @{NSFontAttributeName:[UIFont systemFontOfSize:17]};  //指定字号
    CGRect rect = [string boundingRectWithSize:CGSizeMake(0, 30)/*计算宽度时要确定高度*/ options:NSStringDrawingUsesLineFragmentOrigin |
                   NSStringDrawingUsesFontLeading attributes:dic context:nil];
    return rect.size.width;
}

根据内容计算高度

- (CGFloat)calculateRowHeight:(NSString *)string fontSize:(NSInteger)fontSize{
    NSDictionary *dic = @{NSFontAttributeName:[UIFont systemFontOfSize:fontSize]};//指定字号
    CGRect rect = [string boundingRectWithSize:CGSizeMake(self.view.width - 30, 0)/*计算高度要先指定宽度*/ options:NSStringDrawingUsesLineFragmentOrigin |
                   NSStringDrawingUsesFontLeading attributes:dic context:nil];
    return rect.size.height;
}