When overridden in a derived class, writes out the given white space.
Assembly: System.Xml (in System.Xml.dll)
The string contains non-white space characters.
An XmlWriter method was called before a previous asynchronous operation finished. In this case, InvalidOperationException is thrown with the message “An asynchronous operation is already in progress.”
This method is used to manually format your document.
For the asynchronous version of this method, see WriteWhitespaceAsync.