要创建一个保存为PDF的宏，并带有下拉菜单，你可以使用VBA编程来实现。以下是一个示例代码，展示了如何创建带有下拉菜单的保存为PDF宏：

Sub SaveAsPDFWithDropdown()
    Dim savePath As String
    Dim ws As Worksheet
    
    ' 创建一个新的菜单
    With Application.CommandBars.Add(Name:="SaveAsPDFWithDropdown", Position:=msoBarFloating, _
        Temporary:=True)
        .Visible = True
        
        ' 添加一个下拉按钮
        With .Controls.Add(Type:=msoControlDropdown, Temporary:=True)
            .Caption = "Save As PDF"
            .Tag = "SaveAsPDFDropdown"
            
            ' 添加菜单项
            With .Controls.Add(Type:=msoControlButton, Temporary:=True)
                .Caption = "Save Current Worksheet"
                .OnAction = "SaveCurrentWorksheetAsPDF"
            End With
            
            With .Controls.Add(Type:=msoControlButton, Temporary:=True)
                .Caption = "Save All Worksheets"
                .OnAction = "SaveAllWorksheetsAsPDF"
            End With
        End With
    End With
    
    ' 获取保存路径
    savePath = Application.GetSaveAsFilename(fileFilter:="PDF Files (*.pdf), *.pdf")
    
    ' 如果选择了保存路径，则保存当前工作表为PDF
    If savePath <> "False" Then
        Set ws = ActiveSheet
        ws.ExportAsFixedFormat Type:=xlTypePDF, Filename:=savePath, Quality:=xlQualityStandard
    End If
    
    ' 删除临时菜单
    Application.CommandBars("SaveAsPDFWithDropdown").Delete
End Sub

Sub SaveCurrentWorksheetAsPDF()
    Dim savePath As String
    Dim ws As Worksheet
    
    ' 获取保存路径
    savePath = Application.GetSaveAsFilename(fileFilter:="PDF Files (*.pdf), *.pdf")
    
    ' 如果选择了保存路径，则保存当前工作表为PDF
    If savePath <> "False" Then
        Set ws = ActiveSheet
        ws.ExportAsFixedFormat Type:=xlTypePDF, Filename:=savePath, Quality:=xlQualityStandard
    End If
End Sub

Sub SaveAllWorksheetsAsPDF()
    Dim savePath As String
    Dim ws As Worksheet
    
    ' 获取保存路径
    savePath = Application.GetSaveAsFilename(fileFilter:="PDF Files (*.pdf), *.pdf")
    
    ' 如果选择了保存路径，则保存所有工作表为PDF
    If savePath <> "False" Then
        For Each ws In Worksheets
            ws.ExportAsFixedFormat Type:=xlTypePDF, Filename:=savePath, Quality:=xlQualityStandard, _
                IncludeDocProperties:=True, IgnorePrintAreas:=False
        Next ws
    End If
End Sub

将以上代码复制到Excel的VBA编辑器中（按下Alt + F11），然后保存并关闭VBA编辑器。现在，你可以通过在Excel的菜单栏中选择“开发工具”>“宏”来运行宏。你会看到一个名为“Save As PDF”的下拉菜单，其中包含“Save Current Worksheet”和“Save All Worksheets”选项。选择一个选项后，会弹出对话框，提示你选择保存路径，然后将工作表保存为PDF文件。

希望这个示例可以帮助你创建带有下拉菜单的保存为PDF宏。