How to create a new extension to save an Excel file? Similar to .xlsx is it possible to create new extension using C# eg: .newext

Is it possible to make a new Excel extension like .xlsx? While saving the file, a new extension should appear in the help list. enter image description here

1 answer

  • answered 2021-04-08 03:43 Ethan

    For example, in the WinForm project

      var dialog = new SaveFileDialog();
      dialog.AddExtension = true;
      dialog.Filter = "The custom(*.newext)|*.*";