如何使用vba返回word中段落上方的第一个标题的值？

Sub GetPreviousHeading()
    Dim doc As Document
    Dim para As Paragraph
    Dim prevPara As Paragraph
    Dim heading As String
    
    ' 获取当前文档对象
    Set doc = ActiveDocument
    
    ' 获取选定的段落对象
    Set para = Selection.Paragraphs(1)
    
    ' 获取当前段落的上一个段落
    Set prevPara = para.Previous
    
    ' 循环查找上方的标题
    Do While Not prevPara Is Nothing
        ' 判断上方段落是否为标题
        If prevPara.Style = "Heading 1" Then
            ' 获取标题的文本值
            heading = prevPara.Range.Text
            Exit Do
        End If
        
        ' 继续向上查找
        Set prevPara = prevPara.Previous
    Loop
    
    ' 显示标题值
    MsgBox "上方的第一个标题为：" & heading
End Sub