Gets the filename for the file currently visible in the Visual Studio code editor

CreateGist.cs

        private string GetCurrentFilenameFromEditor()
        {
            var textManager = this.ServiceProvider.GetService(typeof(SVsTextManager)) as IVsTextManager;
            int mustHaveFocus = 1;
            textManager.GetActiveView(mustHaveFocus, null, out IVsTextView textView);

            var userData = textView as IVsUserData;
            if (userData == null)
            {
                // no text view is currently open
                return String.Empty;
            }
            else
            {
                Guid guidViewHost = DefGuidList.guidIWpfTextViewHost;
                userData.GetData(ref guidViewHost, out object holder);
                IWpfTextViewHost viewHost = (IWpfTextViewHost)holder;

                viewHost.TextView.TextDataModel.DocumentBuffer.Properties.TryGetProperty(typeof(ITextDocument), out ITextDocument doc);
                return doc.FilePath;
            }
        }