在c#中将字符串转换为xml会产生空白错误

Question

我不是.NET开发人员,但要完成一项简单(或应该简单!)的任务.我基本上需要从各种字符串值生成一大块XML,并将其格式化为C#中的有效XML对象.我的代码是这样的:

private XDocument BuildPayload(string weight, string fromCountryCode, string fromZipCode, string toCountryCode, string toZipCode, string serviceTypeCode, string packageTypeCode, string pickupTypeCode)
    {

        string upsAccessLiscenseNumber = "xxxxxxxxxxxxxxxx";
        string upsUserID = "xxxxxxxxxx";
        string upsPassword = "xxxxxxxxx";
        string unitOfMeasurementWeight = "LBS";

        StringBuilder sb = new StringBuilder();
        sb.Clear();
        sb.Append("<?xml version='1.0'?>");
        sb.Append(" <AccessRequest xml:lang='en-US'>");
        sb.Append("     <AccessLicenseNumber>").Append(upsAccessLiscenseNumber).Append("</AccessLicenseNumber>");
        sb.Append("     <UserId>").Append(upsUserID).Append("</UserId>");
        sb.Append("     <Password>").Append(upsPassword).Append("</Password>");
        sb.Append(" </AccessRequest>");
        sb.Append("<?xml version='1.0'?>");
        sb.Append(" <RatingServiceSelectionRequest xml:lang='en-US'>");
        sb.Append("     <Request>");
        sb.Append("         <TransactionReference>");
        sb.Append("             <CustomerContext>Rating and Service</CustomerContext>");
        sb.Append("             <XpciVersion>1.0001</XpciVersion>");
        sb.Append("         </TransactionReference>");
        sb.Append("         <RequestAction>Rate</RequestAction>");
        sb.Append("         <RequestOption>Shop</RequestOption>");
        sb.Append("     </Request>");
        sb.Append("     <PickupType>");
        sb.Append("         <Code>").Append(pickupTypeCode).Append("</Code>");
        sb.Append("     </PickupType>");
        sb.Append("     <Shipment>");
        sb.Append("         <Shipper>");
        sb.Append("             <Address>");
        sb.Append("                 <PostalCode>").Append(fromZipCode).Append("</PostalCode>");
        sb.Append("          <CountryCode>").Append(fromCountryCode).Append("</CountryCode>");
        sb.Append("             </Address>");
        sb.Append("         </Shipper>");
        sb.Append("         <ShipTo>");
        sb.Append("             <Address>");
        sb.Append("                 <PostalCode>").Append(toZipCode).Append("</PostalCode>");
        sb.Append("                 <CountryCode>").Append(toCountryCode).Append("</CountryCode>");
        sb.Append("             </Address>");
        sb.Append("         </ShipTo>");
        sb.Append("         <Service>");
        sb.Append("             <Code>").Append(serviceTypeCode).Append("</Code>");
        sb.Append("         </Service>");
        sb.Append("         <Package>");
        sb.Append("             <PackagingType>");
        sb.Append("                 <Code>").Append(packageTypeCode).Append("</Code>");
        //sb.Append("                   <Description>Package</Description>");
        sb.Append("             </PackagingType>");
        sb.Append("             <Description>Rate Shopping</Description>");
        sb.Append("             <PackageWeight>");
        sb.Append("                 <UnitOfMeasurement>");
        sb.Append("                 <Code>").Append(unitOfMeasurementWeight).Append("</Code>");
        sb.Append("                 </UnitOfMeasurement>");
        sb.Append("                 <Weight>").Append(weight).Append("</Weight>");
        sb.Append("             </PackageWeight>");
        sb.Append("         </Package>");
        sb.Append("         <ShipmentServiceOptions/>");
        sb.Append("     </Shipment>");
        sb.Append("</RatingServiceSelectionRequest>");
        XDocument doc = XDocument.Parse(sb.ToString());
        return doc;
    }

但是,当我打电话给我时,我收到一个错误:

Unexpected XML declaration. The XML declaration must be the first node in the document, and no white space characters are allowed to appear before it.

我发现了一些帖子暗示事情(比如放在sb.Clear()那里)但没有任何作用.它似乎认为XML字符串顶部有一些空间,但我看不出有.我能看到的唯一略显狡猾的事情就是那里有两条<?xml version='1.0'?>线.这虽然来自UPS文档,我有一个旧的经典ASP应用程序使用几乎完全相同的XML,它工作正常,所以我不确定这是什么问题.

请问有人能指出我正确的方向吗？

非常感谢.

Answer 1

那么,您生成的XML肯定不是有效的XML 文档.它实际上是2个XML文档,一个接一个.

作为旁注,您可能希望使用.Net XmlWriter类来构建XML文档,因为它更具表现力,可以帮助您查明在构建文档时出现的任何错误.

但是,这应该只是一块XML而不是你真正想要的是将它解析为文档片段并<?XML ... ?>完全删除声明.

Answer 2

据我所知,该行<?xml version='1.0'?>必须是XML文档中的第一行,并且必须只有一个根节点.您没有根节点/或两个根节点:AccessRequest和RatingServiceSelectionRequest.看起来你只是将一个xml doc附加到另一个.

您应该将两个节点RatingServiceSelectionRequest和AccessRequest放在一个根节点中