保存带密码保护PDF的AppleScript报错求助（Monterrey系统）

（原脚本在Big Sur系统可正常运行，升级后无法定位UI元素）

问题描述 #

这段用于保存带密码保护PDF的AppleScript，在Big Sur系统中工作正常，但升级到macOS Monterey后出现报错：无法找到splitter group 3（对应页面样式设置），同时无法定位“PDF”按钮执行“Save as PDF”操作。

原脚本代码 #

-- Don't change this
set FixedPassword to "somePW"

--Change the following for each Review accordingly
set exam to "2"
set session to "5"
set VarPassword to "barcelona"

set outpath to "/Users/user/Dropbox/Physics" & " - " & "Current/2023-1-Spring/UF/2." & " " & "Chapter" & " " & "Reviews/" & ¬
    "Exam" & " " & exam & " " & "Session" & " " & session & "/E" & exam & "S" & session & ".pdf"

set SaveFolder to "/Users/user/Dropbox/Physics" & " - " & "Current/2023-1-Spring/UF/2." & " " & "Chapter" & " " & "Reviews/" & ¬
    "Exam" & " " & exam & " " & "Session" & " " & session

set FileName to "E" & exam & "S" & session & " " & "(Password" & " - " & VarPassword & ").pdf"


--Saving PDF with password protection
tell application "Preview"
    activate
    open outpath
end tell


activate application "Preview"
tell application "System Events"
    tell process "Preview"
        keystroke "p" using command down
        delay 0.5
        tell front window
            repeat until exists sheet 1
                delay 1
            end repeat
            tell sheet 1
                tell splitter group 3
                    click pop up button 3
                    click menu item "Review 216 by 279 mm" of menu 1 of pop up button 3
                end tell
                tell splitter group 3
                    click menu button "PDF"
                    repeat until exists menu 1 of menu button "PDF"
                        delay 3
                    end repeat
                    click menu item "Save as PDF" of menu 1 of menu button "PDF"
                end tell
            end tell
        end tell
        
        -- Make sure the save dialog is visible
        repeat until exists sheet 1 of sheet 1 of front window
            delay 5
        end repeat
        
        tell sheet 1 of sheet 1 of front window
            click button "Security Options..."
        end tell
        
        tell window "PDF Security Options"
            set selected to true
            set focused to true
            (* click the checkbox to on *)
            -- NOTE: for some reason there is a delay of about 6 seconds here, I do not know why
            tell checkbox "Require password to open document"
                click
            end tell
            (* add the password and confirm *)
            keystroke VarPassword
            keystroke (ASCII character 9)
            keystroke VarPassword
            
            tell its checkbox "Require password to copy text, images and other content"
                click
            end tell
            (* add the password and confirm *)
            keystroke FixedPassword
            keystroke (ASCII character 9)
            keystroke FixedPassword
            
            click button "OK"
        end tell
        
        repeat until exists sheet 1 of sheet 1 of front window
            delay 0.2
        end repeat
        
        -- Press command+shift+g to show the "Go" drop down sheet
        keystroke "g" using {command down, shift down}
        repeat until exists sheet of sheet 1 of sheet 1 of front window
            delay 0.2
        end repeat
        
        delay 0.5
        keystroke SaveFolder
        delay 0.5
        
        click button "Go" of sheet of sheet 1 of sheet 1 of front window
        
        -- Now that we are in our desired folder, set the file name and save
        set value of text field 1 of sheet 1 of sheet 1 of front window to FileName
        
        click button "Save" of sheet 1 of sheet 1 of front window
        
    end tell
end tell

报错截图 #

解决思路与建议 #

1. 重新定位UI元素（修复原脚本核心问题） #

macOS Monterey修改了Preview打印窗口的UI层级结构，原脚本依赖的元素索引（如splitter group 3）已失效：

• 使用Xcode Accessibility Inspector（需安装Xcode开发者工具）或第三方工具UI Browser，查看Monterey下Preview打印窗口的UI树，找到页面样式弹窗和PDF按钮的新层级路径或标识符。
• 优先通过控件名称而非索引定位元素，比如将原脚本中定位PDF按钮的代码改为：

  tell sheet 1 of front window
      click menu button "PDF"
      repeat until exists menu 1 of menu button "PDF"
          delay 0.5
      end repeat
      click menu item "Save as PDF" of menu 1 of menu button "PDF"
  end tell
  

2. 优化等待逻辑 #

原脚本的固定延迟在不同系统环境下稳定性差，替换为基于元素存在的判断：

-- 等待打印窗口出现
repeat until exists sheet 1 of front window
    delay 0.5
end repeat

3. 更稳定的替代方案：使用命令行工具 #

避开Preview的UI操作，用qpdf直接给PDF加密，跨版本兼容性更强：

• 先通过Homebrew安装qpdf：

  brew install qpdf
  

• 在AppleScript中调用命令行执行加密：

  set encryptCommand to "qpdf --encrypt " & quoted form of VarPassword & " " & quoted form of FixedPassword & " 256 -- " & quoted form of outpath & " " & quoted form of (SaveFolder & "/" & FileName)
  do shell script encryptCommand
  

  这种方法无需操作Preview界面，完全避免UI结构变化带来的问题。

内容的提问来源于stack exchange，提问作者Caterina