Delphi Code - Read and/or Write Microsoft Excel File Built-In Properties

procedure TForm1.ReadAndOrWriteMicrosoftExcelFileBuiltInProperties(Sender: TObject);
var
   I: Integer;
   ExcelFileName, PropertyName, PropertyValue: String;
   ExcelApplication, ExcelWorkbook, WorkbookProperties, VariantValue: Variant;
begin
     //be sure ComObj and Variants units are included in the "uses" clause

     //be sure a Memo1 VCL is available for outputting the Excel file property names and values

     I := 0;

     ExcelFileName := 'C:\PhysiologyWeb\delphi_code_examples\excel_file.xlsx'; //replace file name with the name of your file
     PropertyName := '';
     PropertyValue := '';

     ExcelApplication := Null;
     ExcelWorkbook := Null;
     WorkbookProperties := Null;
     VariantValue := Null;

     try
        //create Excel OLE
        ExcelApplication := CreateOleObject('Excel.Application');
     except
           ExcelApplication := Null;
           //add error/exception handling code as desired
     end;

     If VarIsNull(ExcelApplication) = False then
        begin
             try
                ExcelApplication.Visible := True; //set to False if you do not want to see the activity in the background
                ExcelApplication.DisplayAlerts := False; //ensures message dialogs do not interrupt the flow of your automation process. May be helpful to set to True during testing and debugging.

                //Open Excel Workbook
                try
                   ExcelWorkbook := ExcelApplication.Workbooks.Open(ExcelFileName);
                except
                      ExcelWorkbook := Null;
                      //add error/exception handling code as desired
                end;

                If VarIsNull(ExcelWorkbook) = False then
                   begin
                        //get BuiltinDocumentProperties
                        try
                           WorkbookProperties := ExcelWorkbook.BuiltinDocumentProperties;
                        except
                              WorkbookProperties := Null;
                              //add error/exception handling code as desired
                        end;

                        If VarIsNull(WorkbookProperties) = False then
                           begin
                                //for a complete list of BuiltinDocumentProperties, see reference below
                                //https://docs.microsoft.com/en-us/dotnet/api/microsoft.office.tools.excel.workbook.builtindocumentproperties?view=vsto-2017


                                //use WorkbookProperties.Count to parse through all BuiltinDocumentProperties (Name/Value) and read/write as desired
                                //iterate through all document properties and retrieve the name and value for each property
                                Memo1.Lines.Add('WorkbookProperties.Count = ' + IntToStr(WorkbookProperties.Count));
                                Memo1.Lines.Add('');
                                For I := 1 to WorkbookProperties.Count do
                                   begin
                                        PropertyName := '';
                                        PropertyValue := '';
                                        VariantValue := Null;

                                        PropertyName := WorkbookProperties.Item[I].Name;

                                        //note: if the value is undefined, an exception is thrown
                                        try
                                           VariantValue := WorkbookProperties.Item[I].Value;
                                           If VarIsNull(VariantValue) = False then PropertyValue := String(VariantValue);
                                        except
                                              PropertyValue := '';
                                        end;

                                        Memo1.Lines.Add('(' + IntToStr(I) + ') ' + PropertyName + ' = ' + PropertyValue);
                                   end;


                                //set document property value by name. for example:
                                WorkbookProperties.Item['Title'].Value := 'Delphi Code Examples';
                                WorkbookProperties.Item['Keywords'].Value := 'Delphi, Object Pascal, Code'; //this is also referred to as the "tag" property
                                WorkbookProperties.Item['Category'].Value := 'Delphi Programming';
                                WorkbookProperties.Item['Company'].Value := 'PhysiologyWeb';


                                Memo1.Lines.Add('');
                                //retrieve document property value by property name. for example:
                                Memo1.Lines.Add('Title = ' + WorkbookProperties.Item['Title'].Value);
                                Memo1.Lines.Add('Keywords = ' + WorkbookProperties.Item['Keywords'].Value);
                                Memo1.Lines.Add('Category = ' + WorkbookProperties.Item['Category'].Value);
                                Memo1.Lines.Add('Company = ' + WorkbookProperties.Item['Company'].Value);


                                //set document property value by property index. for example:
                                WorkbookProperties.Item[1].Value := 'New Document Title';


                                Memo1.Lines.Add('');
                                //read document property namd and value by property index. for example:
                                Memo1.Lines.Add('(1) ' + WorkbookProperties.Item[1].Name + ' = ' + WorkbookProperties.Item[1].Value);


                                //now save the file
                                ExcelWorkbook.Save;
                                //reference
                                //https://learn.microsoft.com/en-us/office/vba/api/excel.workbook.save
                           end;
                   end;
             finally
                    ExcelApplication.Workbooks.Close;
                    ExcelApplication.DisplayAlerts := True;
                    ExcelApplication.Quit;

                    WorkbookProperties := Unassigned;
                    ExcelWorkbook := Unassigned;
                    ExcelApplication := Unassigned;
             end;
        end;
end;