System.Xml.XmlFormatException Class

Namespace: System.Xml

Assembly: System.Xml.dll

Summary

Represents an error that occurs when an XML document does not conform to the XML standard or is otherwise malformed. This exception is thrown by the XML parser when it encounters a non‑recoverable error.

Syntax

public class XmlFormatException : XmlException

Constructors

Constructor	Parameters	Description
`XmlFormatException()`	None	Initializes a new instance of the `XmlFormatException` class.
`XmlFormatException(string message)`	`message`: The error message that explains the reason for the exception.	Initializes a new instance with a custom error message.
`XmlFormatException(string message, Exception innerException)`	`message`, `innerException`	Initializes a new instance with a custom error message and a reference to the inner exception that is the cause.
`XmlFormatException(string message, string sourceUri, int lineNumber, int linePosition)`	Message, source URI, line number, line position.	Provides detailed location information for the error.

Properties

Property	Type	Description
`LineNumber`	`int`	Gets the line number where the error occurred.
`LinePosition`	`int`	Gets the column position within the line where the error occurred.
`SourceUri`	`string`	Gets the URI of the XML document that caused the exception.

Remarks

The XmlFormatException class inherits from XmlException. It adds additional context such as the exact line and position within the source XML. This information is useful for debugging malformed XML payloads.

Example

The following example demonstrates catching an XmlFormatException while loading an XML document.

using System;
using System.Xml;

class Demo
{
    static void Main()
    {
        string xml = @"<root>
                         <item>Value</item>
                         <unclosedTag>Oops
                       </root>";

        try
        {
            var doc = new XmlDocument();
            doc.LoadXml(xml);
        }
        catch (XmlFormatException ex)
        {
            Console.WriteLine($"Format error at line {ex.LineNumber}, position {ex.LinePosition}:");
            Console.WriteLine(ex.Message);
        }
    }
}

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