ArcGIS Pro 2.8 API Reference Guide
GetXml Method (Item)
Example 

ArcGIS.Desktop.Core Namespace > Item Class : GetXml Method
Gets the item’s metadata XML document as a string. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
public string GetXml()
Public Function GetXml() As String

Return Value

Metadata xml string
Exceptions
ExceptionDescription
This method or property must be called within the lambda passed to QueuedTask.Run.
Remarks
Not all items support metadata. Be sure to check for empty string or null as the return value from GetXml.
Example
string gdbXMLMetadataXmlAsString = string.Empty;
gdbXMLMetadataXmlAsString = await QueuedTask.Run(() => gdbMetadataItem.GetXml());
//check metadata was returned
if (!string.IsNullOrEmpty(gdbXMLMetadataXmlAsString))
{
  //use the metadata
}
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

Item Class
Item Members