如何解決 System.Xml.Schema.XmlSchemaValidationException

Question

我正在嘗試使用在線 XSD 驗證 XML。這是我 controller 的當前代碼：

using System;
using System.IO;
using System.Net;
using System.Xml;
using System.Xml.Linq;
using System.Xml.Schema;
using Microsoft.AspNetCore.Mvc;

namespace EINV.API.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class XmlController : Controller
    {   
        [HttpPost]
        public IActionResult ValidateXml2(IFormFile xmlFile, string xsdUrl)
        {

            XmlReaderSettings settings = new XmlReaderSettings();
            settings.XmlResolver = new XmlXsdResolver();     // Need this for resolving include and import
            settings.ValidationType = ValidationType.Schema; // This might not be needed, I am using same settings to validate the input xml
            //settings.DtdProcessing = DtdProcessing.Parse;    // I have an include that is dtd. maybe I should prohibit dtd after I compile the xsd files.
            settings.Schemas.Add(null, xsdUrl); // https://docs.oasis-open.org/ubl/os-UBL-2.1/xsd/maindoc/UBL-Invoice-2.1.xsd
            settings.Schemas.Compile();
            settings.ValidationType = ValidationType.Schema;

            XmlReader reader = XmlReader.Create(xmlFile.OpenReadStream(), settings, "https://docs.oasis-open.org/ubl/os-UBL-2.1/xsd/maindoc/");
            XmlDocument document = new XmlDocument();
            document.Load(reader);

            ValidationEventHandler eventHandler = new ValidationEventHandler(ValidationEventHandler);

            // the following call to Validate succeeds.
            document.Validate(eventHandler);
            // Load the XML file into an XmlDocument

            return Ok();
        }

        protected class XmlXsdResolver : XmlUrlResolver
        {
            public override object GetEntity(Uri absoluteUri, string role, Type ofObjectToReturn)
            {
                return base.GetEntity(absoluteUri, role, ofObjectToReturn);
            }
        }

        private void ValidationEventHandler(object? sender, ValidationEventArgs? e)
        {
            if (e?.Severity == XmlSeverityType.Error)
            {
                throw new Exception("XML validation error: " + e.Message);
            }
        }
    }
}

在嘗試解決此問題時，我參考了其他幾篇文章，例如：

當所有 my.XSD 都存儲為資源時，如何解析 an.XSD 的 schemaLocation 屬性？

編譯兩個嵌入式 XSD：錯誤“無法解析‘schemaLocation’屬性

針對 xsd 驗證 xml，該 c# 包含並導入

但總是以同樣的錯誤結束：

System.Xml.Schema.XmlSchemaValidationException: 'The 'urn:oasis:names:specification:ubl:schema:xsd:CommonExtensionComponents-2:UBLExtensions' element is not declared.'

我正在使用的 XML 位於此處： https://docs.oasis-open.org/ubl/os-UBL-2.1/xml/UBL -Invoice-2.1-Example.xml

我正在使用的 XSD 位於： https://docs.oasis-open.org/ubl/os-UBL-2.1/xsd/maindoc/UBL-Invoice-2.1.xsd

Answer 1

我認為你需要設置settings.Schemas.XmlResolver = new XmlUrlResolver(); 同樣，作為標志settings.ValidationFlags |= XmlSchemaValidationFlags.ProcessSchemaLocation; 前。

這可能會讓你走得更遠，因為我認為有些模式（例如簽名）已導入但未找到。 所以最后你需要確保你有這些模式的本地副本，並讓你的解析器使用本地副本。