Hey there, let’s tackle this question. From what I’ve gathered, while many office suites do background auto-save for DOCX (OpenXML) documents, you absolutely can close without keeping those changes—here’s how to do it depending on the tool you’re using:

• Microsoft Word (Windows/Mac)
  The moment you try to close a modified DOCX, Word will pop up a clear prompt with three options: Save, Don’t Save, and Cancel. Even with auto-save turned on, picking Don’t Save will toss all unsaved edits and close the document. If you’re not seeing this prompt, double-check your auto-save settings (File > Options > Save) — it’s rare, but some configurations might skip the prompt if set to overwrite immediately (not the default).

• LibreOffice Writer
  Just like Word, closing a modified document will trigger a prompt asking if you want to save changes. Select Discard Changes (or Don’t Save, depending on your version) to close without preserving edits. LibreOffice’s auto-save creates temporary recovery files, but these won’t overwrite your original document unless you explicitly choose to save.

• Programmatic Workflows (e.g., OpenXML SDK)
  If you’re editing DOCX files via code with the OpenXML SDK, the key is simple: don’t call the Save() method on your WordprocessingDocument instance. When you wrap the document in a using block, it will close automatically without persisting changes if you skip the save call. Example snippet:

  using (var doc = WordprocessingDocument.Open("your-document.docx", true))
  {
      // Your editing logic goes here
  }
  // No Save() call = changes aren't saved when the block disposes
  

If you’re still not seeing these prompts in your office app, it’s worth verifying your save settings—sometimes auto-save can be misconfigured to save silently, but that’s not the standard setup.

内容的提问来源于stack exchange，提问作者Len White