c# 改变PPT文本框字体

[爱妃大大大]

问题很简单，我用c#在PPT上添加一个文本框，但是文本框内的字体始终是宋体，所以麻烦大家帮我看一下，谢谢。

Microsoft.Office.Interop.PowerPoint.Application PPT = new Microsoft.Office.Interop.PowerPoint.ApplicationClass();
Microsoft.Office.Interop.PowerPoint.Presentations MyPresSet;
Microsoft.Office.Interop.PowerPoint._Presentation MyPres;
Microsoft.Office.Interop.PowerPoint.Slides MySlides;
Microsoft.Office.Interop.PowerPoint._Slide MySlide;
Microsoft.Office.Interop.PowerPoint.TextRange MyTextRng;


MyPresSet = PPT.Presentations;
MyPres = MyPresSet.Open("PPT文件位置", MsoTriState.msoFalse, MsoTriState.msoFalse, MsoTriState.msoFalse);
MySlides = MyPres.Slides;
//创建幻灯片第一页
MySlide = MySlides.Add(2, Microsoft.Office.Interop.PowerPoint.PpSlideLayout.ppLayoutBlank);

MySlide.Shapes.AddTextbox(MsoTextOrientation.msoTextOrientationHorizontal, 10, 10, 100, 100);
MyTextRng = MySlide.Shapes[1].TextFrame.TextRange;
MyTextRng.Font.Name = "微软雅黑";
MyTextRng.Text = "大家好";
MyTextRng.Font.Size = 30;

MySlide.Shapes.AddTextbox(MsoTextOrientation.msoTextOrientationHorizontal, 10, 120, 100, 100);
MyTextRng = MySlide.Shapes[2].TextFrame.TextRange;
MyTextRng.Text = "你真棒";
MyTextRng.Font.Bold = MsoTriState.msoTrue;
MyTextRng.Font.Underline = MsoTriState.msoTrue;
MyTextRng.Font.Name = "华文细黑";
MyTextRng.Font.Size = 30;

[爱妃大大大]

顶起，别沉，谢谢大家