Question

在使用文化信息时，将数字转换为double时，我遇到了奇怪的行为使用荷兰文化转换- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath { static NSString *cellID = @"cellID"; RACollectionViewCell *cell = [self.collectionView dequeueReusableCellWithReuseIdentifier:cellID forIndexPath:indexPath]; [cell.imageView removeFromSuperview]; cell.imageView.frame = cell.bounds; cell.imageView.image = [UIImage imageNamed:[_photosArray objectAtIndex:indexPath.item]]; cell.backgroundColor = [UIColor lightGrayColor]; [cell.contentView addSubview:cell.imageView]; UIButton *addBtn =[[UIButton alloc]init]; addBtn.tag=indexPath.row; deleteBtn.frame = CGRectMake(100, 100, 19, 19); UIImage *img=[UIImage imageNamed:@"ic_add_photo.png"]; [addBtn setImage:img forState:UIControlStateNormal]; [addBtn addTarget:self action:@selector(addBtnAction) forControlEvents:UIControlEventTouchUpInside]; [cell.contentView addSubview:addBtn]; return cell; } -(void)addBtnAction { UIAlertController *actionsheetController = [[UIAlertController alloc]init]; UIAlertAction *library = [UIAlertAction actionWithTitle:@"Choose from Library" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) { // Library button tapped [self performSelector:@selector(libraryBtnAction) withObject:nil]; }]; [actionsheetController addAction:library]; actionsheetController.view.tintColor = [UIColor darkGrayColor]; [self presentViewController:actionsheetController animated:YES completion:nil]; } -(void)libraryBtnAction { UIImagePickerController *picker = [[UIImagePickerController alloc]init]; picker.delegate = self; picker.allowsEditing = YES; picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary; [self presentViewController:picker animated:YES completion:nil]; } - (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info { chosenImage = info[UIImagePickerControllerEditedImage]; cell.imageView.image = chosenImage; [_collectionView reloadData]; [picker dismissViewControllerAnimated:YES completion:NULL]; }时，处理正确。如果我使用美国文化转换"3,3"，则返回"3,3"。我期待一个错误。看我的例子：

处理此问题的正确方法是什么？当小数（或千位）分隔符无效时，我更喜欢异常。

Answer 1

如果您只想解析它，我会使用专用的解析方法，您可以在其中设置Numberstyles

以下代码将抛出FormatException

var culture =new CultureInfo("en-US");
var result = double.Parse("3,3", NumberStyles.AllowDecimalPoint, culture);

有关详细信息，请参阅Double.Parse Method

Answer 2

与Boas Enkler的回答一起，我已经能够解决问题了。因此，首先，我将根据当前的文化扫描千位分隔符的输入。最后我将输入值解析为double。

private static string RemoveThousandSeparator(string input)
    {
        Regex removeThousandSeparatorExpr = new Regex(@"^-?(?:\d+|\d{1,3}(?:\"
                        + <CultureInfo>.NumberGroupSeparator + @"\d{3})+)(?:\"
                        + <CultureInfo>.NumberDecimalSeparator + @"\d+)?$");
        Match match = removeThousandSeparatorExpr.Match(input);
        if (match.Success)
        {
            input = input.Replace(<CultureInfo>.NumberGroupSeparator, "");
        }
        else
        {
            throw new Exception("Invalid input value");
        }

        return input;
    }

带小数分隔符的数字错误地转换为Double

2 个答案: