根據內容計算寬度

- (CGFloat)calculateRowWidth:(NSString *)string {
    NSDictionary *dic = @{NSFontAttributeName:[UIFont systemFontOfSize:17]};  //指定字號
    CGRect rect = [string boundingRectWithSize:CGSizeMake(0, 30)/*計算寬度時要確定高度*/ options:NSStringDrawingUsesLineFragmentOrigin |
                   NSStringDrawingUsesFontLeading attributes:dic context:nil];
    return rect.size.width;
}
 

根據內容計算高度

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