如何使用C#以编程方式将RTF文本插入到PowerPoint文本框架中？

using PowerPoint = Microsoft.Office.Interop.PowerPoint;
using Word = Microsoft.Office.Interop.Word;

PowerPoint.Application pptApp = new PowerPoint.Application();
PowerPoint.Presentation pptPresentation = pptApp.Presentations.Add();

PowerPoint.Slide pptSlide = pptPresentation.Slides.Add(1, PowerPoint.PpSlideLayout.ppLayoutBlank);

PowerPoint.Shape pptShape = pptSlide.Shapes.AddTextbox(Microsoft.Office.Core.MsoTextOrientation.msoTextOrientationHorizontal, 100, 100, 400, 200);
PowerPoint.TextFrame pptTextFrame = pptShape.TextFrame;

Word.Application wordApp = new Word.Application();
Word.Document wordDoc = wordApp.Documents.Add();

string rtfText = @"{\rtf1\ansi Hello, this is RTF text.}";
wordDoc.Range().InsertAfter(rtfText);

pptTextFrame.TextRange.InsertAfter(wordDoc.Content.Text);

wordDoc.Close();
wordApp.Quit();
pptApp.Quit();