在 c# 中验证后无法从 Xmlreader 检索属性名称/值

Question

我需要编写一段 C# 代码，以便在验证失败时从 XML 中提取属性信息。下面的代码能够为我提供验证失败的确切属性，但我还需要父节点中存在的属性的附加信息。

XML：

<Payload xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlVersion="1.0" createDate="2023-11-07T14:23:08" messageType="TEST">
<Orders>
<OrderHeader resultsIndicator="F" orderNumber="2000100" orderStatus="FIN" latestShipDate="4/23/2023 12:00:00 AM" cusNumber="791053" cusName="Apple, Ms.Rose" deliveryTerms="HOME" paymentType="AMEX" Destination="TX">
<OrderDetail resultsIndicator="F" lot="1234" sequence="01" invoice="FGD123401" finalDestination="75013" resultsMessage="DELIVERED" brandNumber="100141" brandName="LG">
<OrderCostingDetail expenseCode="ADMIN" expenseCategory="ADM" rate="2499.50" indicator="F" qualifier="SALE" unitCost="2499.50" level="002"/>
<OrderCostingDetail expenseCode="ADMIN" expenseCategory="ADM" rate="125.00" indicator="F" qualifier="SALE" unitCost="" level="002"/>
<OrderCostingDetail expenseCode="ADMIN" expenseCategory="ADM" rate="5879.20" indicator="F" qualifier="SALE" unitCost="5879.20" level="002"/>
</OrderDetail>
</OrderHeader>
<OrderHeader resultsIndicator="I" orderNumber="2000101" orderStatus="INIT" latestShipDate="12/10/2023 12:00:00 AM" cusNumber="56782" cusName="Roy, Mr.Ralph" deliveryTerms="HOME" paymentType="VISA" Destination="TX">
<OrderDetail resultsIndicator="I" lot="1234" sequence="01" invoice="FGD123401" finalDestination="75013" resultsMessage="DELIVERED" brandNumber="100141" brandName="LG">
<OrderCostingDetail expenseCode="ADMIN" expenseCategory="ADM" rate="24.00" indicator="I" qualifier="SALE" unitCost="24.00" level="004"/>
</OrderDetail>
</OrderHeader>
</Orders>
</Payload>

代码：

 private static void PerformValidation(XmlTextReader xmlTextReader, 
            XmlSchemaSet schemas)
        {
   
            if (schemas == null)
            {
                throw new ArgumentNullException("schemas");
            }

            XmlReaderSettings settings = new XmlReaderSettings();
            settings.ValidationType = ValidationType.Schema;
            settings.Schemas = schemas;
            settings.ValidationFlags = XmlSchemaValidationFlags.ReportValidationWarnings; //sarul1
            // settings.ValidationEventHandler += (sender, args) => error = ValidationCallback(sender, args);
            string chkatt = string.Empty;
            using (XmlReader reader = XmlReader.Create(xmlTextReader, settings))
            {
                try
                {
                    do
                    {
                      chkatt = string.Concat("orderNo.: ",reader.GetAttribute("orderNumber"), ", Lot:", reader.GetAttribute("lot"), ", Seq:", reader.GetAttribute("sequence"));
                    } while (reader.Read()) ;
                }
                catch(Exception ex)
                {
                    string error = ex.Message.ToString() + chkatt;
                }
               
                finally
                {
                    reader.Close();   
                }
            }

        }

我在主函数中调用上述方法来根据预定义的模式验证是否存在 NULL 字段。我收到错误“‘unitCost’属性无效...字符串‘’不是有效的十进制值。”我需要向此消息添加其他属性信息，如 orderNumber、Lot 和 Sequence（在本例中为 orderNumber：2000100，Lot：1234，Seq：01），但我无法使用此代码实现。请帮助我前进！

Answer 1

PerformValidation

函数在错误消息中缺少上下文，因为它没有跟踪父节点中的属性值。

考虑这个更新的代码：

private static void PerformValidation(XmlTextReader xmlTextReader, XmlSchemaSet schemas)

{ if（模式 == null） { 抛出新的ArgumentNullException（“模式”）； }

XmlReaderSettings settings = new XmlReaderSettings();
settings.ValidationType = ValidationType.Schema;
settings.Schemas = schemas;
settings.ValidationFlags = XmlSchemaValidationFlags.ReportValidationWarnings;

string orderNumber = string.Empty;
string lot = string.Empty;
string sequence = string.Empty;

using (XmlReader reader = XmlReader.Create(xmlTextReader, settings))
{
    try
    {
        while (reader.Read())
        {
            if (reader.NodeType == XmlNodeType.Element)
            {
                if (reader.Name == "OrderHeader")
                {
                    orderNumber = reader.GetAttribute("orderNumber");
                }
                else if (reader.Name == "OrderDetail")
                {
                    lot = reader.GetAttribute("lot");
                    sequence = reader.GetAttribute("sequence");
                }
            }
            else if (reader.NodeType == XmlNodeType.Attribute && reader.Value == string.Empty)
            {
                string errorMessage = $"Validation error in OrderNo.: {orderNumber}, Lot: {lot}, Seq: {sequence}. ";
                errorMessage += $"Attribute '{reader.Name}' is invalid. The string '' is not a valid Decimal value.";

                // Handle or log the error message as needed
                Console.WriteLine(errorMessage);
            }
        }
    }
    catch (Exception ex)
    {
        string error = ex.Message.ToString();
        // Handle or log the exception as needed
        Console.WriteLine(error);
    }
    finally
    {
        reader.Close();
    }
}

}

此代码引入了变量（订单编号、批次和序列）来存储这些值，以便在发生验证错误时提供更多信息丰富的错误消息。

尝试一下，如果需要进一步修改，请告诉我。 如果该答案解决了您的问题，请不要忘记标记为答案。 :)