Check well-formed XML without a try/catch?

Question

Does anyone know how I can check if a string contains well-formed XML without using something like XmlDocument.LoadXml() in a try/catch block? I've got input that may or may not be XML, and I want code that recognises that input may not be XML without relying on a try/catch, for both speed and on the general principle that non-exceptional circumstances shouldn't raise exceptions. I currently have code that does this;

private bool IsValidXML(string value)
    {
        try
        {
            // Check we actually have a value
            if (string.IsNullOrEmpty(value) == false)
            {
                // Try to load the value into a document
                XmlDocument xmlDoc = new XmlDocument();

                xmlDoc.LoadXml(value);

                // If we managed with no exception then this is valid XML!
                return true;
            }
            else
            {
                // A blank value is not valid xml
                return false;
            }
        }
        catch (System.Xml.XmlException)
        {
            return false;
        }
    }

But it seems like something that shouldn't require the try/catch. The exception is causing merry hell during debugging because every time I check a string the debugger will break here, 'helping' me with my pesky problem.

Answer 1

I don't know a way of validating without the exception, but you can change the debugger settings to only break for XmlException if it's unhandled - that should solve your immediate issues, even if the code is still inelegant.

To do this, go to Debug / Exceptions... / Common Language Runtime Exceptions and find System.Xml.XmlException, then make sure only "User-unhandled" is ticked (not Thrown).