Problems with Textholders

I have been working with modifying text in various placeholders:

Dim th As TextHolder = pholders(0)

I find that this works fine when I am using a placeholder type of 'CenteredTitle2', which is the main placeholder on a title slide, but not when I am using a 'Subtitle' placeholder.

I get this: System.InvalidCastException: Specified cast is not valid.

Can you help me out and explain why this happens?

Thanks,
Tom

Slide.Placeholders collection contains Placeholder and TextHolder objects.
Placeholder can’t be casted to the TextHolder type.

Alexey,

I am following code on your WIKI:

Dim pholders As Placeholders = GetSlideByPosition(pres, 1).Placeholders
Dim th As TextHolder = pholders(0)
If th.Text = "PH1" Then
th.Paragraphs(0).Portions(0).Text = "Hello World "
End If

How else (please, with actual code example) can I modify the text within the 2 placeholders on a title slide?

I have tried this also:

Dim oShape2 As Slides.Shape
oShape2 = _pptdoc.Slides(0).Shapes(0)
oShape2.TextFrame.Text = "Testing"

This does not produce an error, but also does not change the text on the slide when viewed.

Thanks for your help, Tom