System.InvalidOperationException: There is an error in XML document (0, 0). ---> System.Xml.XmlException: Root element is missing.

Question

System.InvalidOperationException: There is an error in XML document (0, 0). ---> System.Xml.XmlException: Root element is missing.

Julio Bello 221

Hi, Everybody!...

I am trying to parse the following XML string...

<PostShipmentResponse>
	<Account>L303061</Account>
	<ParcelhubShipmentId>2815849350974933</ParcelhubShipmentId>
	<Reference1>ordernumber1</Reference1>
	<Reference2>label reference</Reference2>
	<SpecialInstructions>leave in shed</SpecialInstructions>
	<ContentsDescription>overview of what's being sent</ContentsDescription>
	<Blobs />
	<ModifiedTime>2023-09-27T18:20:59.9200581+01:00</ModifiedTime>
	<CurrencyCode>GBP</CurrencyCode>
	<Deleted>false</Deleted>
	<HasBeenManifested>false</HasBeenManifested>
	<Department>L3030611</Department>
	<Attributes />
	<Returnable>false</Returnable>
</PostShipmentResponse>

I applied the following XML attributes...

    public partial class PostShipmentResponse
    {
        //[XmlElement(ElementName = "Shipment")]
        //public Shipment Shipment { get; set; }

        [XmlElement(ElementName = "Account")]
        public string Account { get; set; }

        //[XmlElement(ElementName = "ServiceInfo")]
        //public ServiceInfo ServiceInfo { get; set; }

        [XmlElement(ElementName = "ParcelhubShipmentId")]
        public string ParcelhubShipmentId { get; set; }

        //[XmlElement(ElementName = "ShippingInfo")]
        //public ShippingInfo ShippingInfo { get; set; }

        //[XmlElement(ElementName = "CollectionDetails")]
        //public CollectionDetails CollectionDetails { get; set; }

        //[XmlElement(ElementName = "CollectionAddress")]
        //public CollectionAddress CollectionAddress { get; set; }

        //[XmlElement(ElementName = "DeliveryAddress")]
        //public DeliveryAddress DeliveryAddress { get; set; }

        //[XmlElement(ElementName = "DeliverToStoreOrLockerID")]
        //public string DeliverToStoreOrLockerID { get; set; }

        [XmlElement(ElementName = "Reference1")]
        public string Reference1 { get; set; }

        [XmlElement(ElementName = "Reference2")]
        public string Reference2 { get; set; }

        [XmlElement(ElementName = "SpecialInstructions")]
        public string SpecialInstructions { get; set; }

        [XmlElement(ElementName = "ContentsDescription")]
        public string ContentsDescription { get; set; }

        //[XmlElement(ElementName = "Packages")]
        //public Packages Packages { get; set; }

        //[XmlElement(ElementName = "Enhancements")]
        //public Enhancements Enhancements { get; set; }

        [XmlElement(ElementName = "Blobs")]
        public string Blobs { get; set; }

        [XmlElement(ElementName = "ModifiedTime")]
        public string ModifiedTime { get; set; }

        [XmlElement(ElementName = "CurrencyCode")]
        public string CurrencyCode { get; set; }

        //[XmlElement(ElementName = "CustomsDeclarationInfo")]
        //public CustomsDeclarationInfo CustomsDeclarationInfo { get; set; }

        [XmlElement(ElementName = "Deleted")]
        public string Deleted { get; set; }

        [XmlElement(ElementName = "HasBeenManifested")]
        public string HasBeenManifested { get; set; }

        //[XmlElement(ElementName = "ShipmentTags")]
        //public ShipmentTags ShipmentTags { get; set; }

        //[XmlElement(ElementName = "Stream")]
        //public string Stream { get; set; }

        [XmlElement(ElementName = "Department")]
        public string Department { get; set; }

        [XmlElement(ElementName = "Attributes")]
        public string Attributes { get; set; }

        [XmlElement(ElementName = "Returnable")]
        public string Returnable { get; set; }

        //[XmlElement(ElementName = "NominatedDeliveryDate")]
        //public NominatedDeliveryDate NominatedDeliveryDate { get; set; }

        //[XmlElement(ElementName = "ProductTypeCode")]
        //public string ProductTypeCode { get; set; }

        //[XmlAttribute(AttributeName = "xsd")]
        //public string Xsd { get; set; }

        //[XmlAttribute(AttributeName = "xsi")]
        //public string Xsi { get; set; }

        //[XmlAttribute(AttributeName = "xmlns")]
        //public string Xmlns { get; set; }

        //[XmlText]
        //public string Text { get; set; }
    }

I'm executing the following code...

        private TResponse XmlStringToObject<TResponse>(string xmlString)
        {
            using (var memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(xmlString)))
            {
                XmlSerializer xmlSerializer;

                xmlSerializer = new XmlSerializer(typeof(TResponse));

                return (TResponse)xmlSerializer.Deserialize(memoryStream);
            }
        }

I'm getting the followig error...

System.InvalidOperationException: There is an error in XML document (0, 0). ---> System.Xml.XmlException: Root element is missing.

What am I going wrong?

Accepted answer

1 additional answer

Your answer

Answer 1

Viorel 122.6K

It seems that you must execute memoryStream.Position = 0 between attempts.

Julio Bello 221

Hi, @Viorel

Your comment was precisely the correct answer. My code now looks like this...

    private TResponse XmlStringToObject<TResponse, TError>(string xmlString, ref TError error) where TResponse : class
    {
        using (var memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(xmlString)))
        {
            XmlSerializer xmlSerializer;

            //Check for Error Response first
            try
            {
                xmlSerializer = new XmlSerializer(typeof(TError));
                error = (TError)xmlSerializer.Deserialize(memoryStream);

                if (error != null)
                    return null;
            }
            catch (InvalidOperationException)
            {
                // Apparently, it is not an Error Response
                memoryStream.Position = 0;
            }

            // No Error Response
            xmlSerializer = new XmlSerializer(typeof(TResponse));

            return (TResponse)xmlSerializer.Deserialize(memoryStream);
        }
    }

Answer 2

Hi @Julio Bello,

I tested the code you provided and there is no problem. You didn't provide a method to read the xml, maybe that's a problem.

You can add the following content to your XML and see if an error is reported.

<?xml version="1.0" encoding="utf-8"?>
<rootElement>
...
</rootElement>

Or try using my test method, here is the complete test code:

public class Program
{
    public static void Main(string[] args)
    {
        Serializer ser = new Serializer();
        string path = string.Empty;
        string xmlInputData = string.Empty;
        xmlInputData = File.ReadAllText(@"C:\Users\Administrator\Desktop\test.xml");
        var customer = ser.XmlStringToObject<PostShipmentResponse>(xmlInputData);
        Console.WriteLine(customer);

    }
    public class Serializer
    {
        public TResponse XmlStringToObject<TResponse>(string xmlString)
        {
            using (var memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(xmlString)))
            {
                XmlSerializer xmlSerializer;

                xmlSerializer = new XmlSerializer(typeof(TResponse));

                return (TResponse)xmlSerializer.Deserialize(memoryStream);
            }
        }
    }


    public partial class PostShipmentResponse
    {
        //[XmlElement(ElementName = "Shipment")]
        //public Shipment Shipment { get; set; }

        [XmlElement(ElementName = "Account")]
        public string Account { get; set; }

        //[XmlElement(ElementName = "ServiceInfo")]
        //public ServiceInfo ServiceInfo { get; set; }

        [XmlElement(ElementName = "ParcelhubShipmentId")]
        public string ParcelhubShipmentId { get; set; }

        //[XmlElement(ElementName = "ShippingInfo")]
        //public ShippingInfo ShippingInfo { get; set; }

        //[XmlElement(ElementName = "CollectionDetails")]
        //public CollectionDetails CollectionDetails { get; set; }

        //[XmlElement(ElementName = "CollectionAddress")]
        //public CollectionAddress CollectionAddress { get; set; }

        //[XmlElement(ElementName = "DeliveryAddress")]
        //public DeliveryAddress DeliveryAddress { get; set; }

        //[XmlElement(ElementName = "DeliverToStoreOrLockerID")]
        //public string DeliverToStoreOrLockerID { get; set; }

        [XmlElement(ElementName = "Reference1")]
        public string Reference1 { get; set; }

        [XmlElement(ElementName = "Reference2")]
        public string Reference2 { get; set; }

        [XmlElement(ElementName = "SpecialInstructions")]
        public string SpecialInstructions { get; set; }

        [XmlElement(ElementName = "ContentsDescription")]
        public string ContentsDescription { get; set; }

        //[XmlElement(ElementName = "Packages")]
        //public Packages Packages { get; set; }

        //[XmlElement(ElementName = "Enhancements")]
        //public Enhancements Enhancements { get; set; }

        [XmlElement(ElementName = "Blobs")]
        public string Blobs { get; set; }

        [XmlElement(ElementName = "ModifiedTime")]
        public string ModifiedTime { get; set; }

        [XmlElement(ElementName = "CurrencyCode")]
        public string CurrencyCode { get; set; }

        //[XmlElement(ElementName = "CustomsDeclarationInfo")]
        //public CustomsDeclarationInfo CustomsDeclarationInfo { get; set; }

        [XmlElement(ElementName = "Deleted")]
        public string Deleted { get; set; }

        [XmlElement(ElementName = "HasBeenManifested")]
        public string HasBeenManifested { get; set; }

        //[XmlElement(ElementName = "ShipmentTags")]
        //public ShipmentTags ShipmentTags { get; set; }

        //[XmlElement(ElementName = "Stream")]
        //public string Stream { get; set; }

        [XmlElement(ElementName = "Department")]
        public string Department { get; set; }

        [XmlElement(ElementName = "Attributes")]
        public string Attributes { get; set; }

        [XmlElement(ElementName = "Returnable")]
        public string Returnable { get; set; }

        //[XmlElement(ElementName = "NominatedDeliveryDate")]
        //public NominatedDeliveryDate NominatedDeliveryDate { get; set; }

        //[XmlElement(ElementName = "ProductTypeCode")]
        //public string ProductTypeCode { get; set; }

        //[XmlAttribute(AttributeName = "xsd")]
        //public string Xsd { get; set; }

        //[XmlAttribute(AttributeName = "xsi")]
        //public string Xsi { get; set; }

        //[XmlAttribute(AttributeName = "xmlns")]
        //public string Xmlns { get; set; }

        //[XmlText]
        //public string Text { get; set; }
    }
}

User's image

Best regards,
Lan Huang

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Julio Bello 221 Reputation points

2023-09-28T07:24:27.92+00:00

Thank-you for trying to help me with my issue.

Perhaps the reason why my error was not reproducible is because I "simplified" the method I executed to "abbreviate" the problem statement.

What I am REALLY trying to do is to parse either one of TWO possible XML strings. One is a PostShipmentResponse (which was already defined). The other is an Error response (See below).

[XmlRoot(ElementName = "Error"] public partial class Error { [XmlElement(ElementName = "Message")] public string Message { get; set; } }

My approach was to first check for a possible Error response. If not, then assume a PostShipmentResponse (See below).

private TResponse XmlStringToObject<TResponse, TError>(string xmlString, ref TError error) where TResponse : class { using (var memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(xmlString))) { XmlSerializer xmlSerializer; //Check for Error Response first try { xmlSerializer = new XmlSerializer(typeof(TError)); error = (TError)xmlSerializer.Deserialize(memoryStream); if (error != null) return null; } catch (InvalidOperationException) { // Apparently, it is not an Error Response } // No Error Response xmlSerializer = new XmlSerializer(typeof(TResponse)); return (TResponse)xmlSerializer.Deserialize(memoryStream); } }

When you confirmed that NOTHING was wrong with the original method, I then commented out the "Error response" block of code and voilà ... It worked!

Apparently, when the attempting to parse an Error response fails (in the event of a PostShipmentResponse), the second attempt also fails. Is there a way to "clear" all exceptions before attempting to parse a PostShipmentResponse?
Lan Huang-MSFT 30,186 Reputation points Microsoft External Staff

2023-09-28T09:52:45.9433333+00:00

Hi @Julio Bello,

From my understanding, you have two responses, one is PostShipmentResponse and other is Error response.

You want to deserialize both responses. When deserialization fails, an InvalidOperationException is thrown. I don't quite understand your comment:(// Apparently, it is not an Error Response).

You can refer to the code below (untested) and modify your own code.

private (TResponse, TError) XmlStringToObject<TResponse, TError>(string xmlString, ref string error) where TResponse : class { (TResponse,TError ) result = (default,default) ; try { XmlSerializer xmlSerializer; if (error == null) { var memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(xmlString)); xmlSerializer = new XmlSerializer(typeof(TResponse)); result.Item1 = (TResponse)xmlSerializer.Deserialize(memoryStream); } else { var memoryStream = new MemoryStream(Encoding.UTF8.GetBytes(error)); xmlSerializer = new XmlSerializer(typeof(TError)); result.Item2 = (TError)xmlSerializer.Deserialize(memoryStream); } } catch (InvalidOperationException e) { Console.WriteLine(e.InnerException); } return (result.Item1,result.Item2); }
Julio Bello 221 Reputation points

2023-09-28T14:28:56.64+00:00

Hi, @Lan Huang-MSFT

I wish to thank-you again for your efforts... When you confirmed that NOTHING was wrong with the original method, that made me ask: Is there a way to "clear" all exceptions before attempting to parse a PostShipmentResponse?

Viorel's response was precisely what I was missing in my code.

Truly grateful

Share via

System.InvalidOperationException: There is an error in XML document (0, 0). ---> System.Xml.XmlException: Root element is missing.

1 additional answer

Your answer