Ubuntu 20.04下LibreOffice Impress BASIC报错：未找到createInstance方法

问题场景 #

在Ubuntu 20.04 LTS系统上运行LibreOffice 7.4.5.2 Impress的BASIC代码时，执行以下代码出现BASIC runtime error: property or method not found: createInstance错误，调试显示createInstance方法已加载但仍报错：

REM  *****  BASIC  *****

Option Explicit
Sub CreateAIHistoryPresentation1()
    Dim oDoc As Object
    Dim oPresentation As Object
    Dim oSlide As Object
    Dim oShape As Object
    Dim oText As Object
    Dim oTitle As Object
    Dim oImage As Object
    Dim i As Integer
    Dim service01Name As String
    Dim objDoc As Object
    
    'objDoc.BasicLibraries.LoadLibrary("Tools")
    if Not BasicLibraries.isLibraryLoaded("Tools") Then
        BasicLibraries.loadLibrary("Tools")
    End if
    GlobalScope.BasicLibraries.LoadLibrary("Tools")
    
    ' Create a new presentation document
    oDoc = StarDesktop.LoadComponentFromURL("private:factory/simpress", "_blank", 0, Array())
    oPresentation = oDoc.getPresentation
    oPresentation.dbg_properties
    oPresentation.dbg_methods
    
    ' Page 1: Title Slide
    oSlide = oPresentation.createInstance("com.sun.star.presentation.Slide")
End Sub

错误原因 #

oPresentation是com.sun.star.presentation.Presentation服务实例，该对象并不提供createInstance方法，代码混淆了LibreOffice UNO对象模型的层级——创建幻灯片需要操作文档的DrawPages集合，而非Presentation对象。

修正方案 #

替换创建幻灯片的代码段，改为通过文档的DrawPages集合插入新幻灯片：

' Page 1: Title Slide
Dim oDrawPages As Object
oDrawPages = oDoc.getDrawPages()
oSlide = oDrawPages.insertNewByIndex(0) ' 在索引0位置插入新幻灯片

如果需要创建带预设版式的幻灯片，可在插入后设置版式：

' 设置为标题幻灯片版式
oSlide.Layout = com.sun.star.presentation.FadeEffect.TITLE

内容的提问来源于stack exchange，提问作者tony gil