NullPtrEx while calling "invisible" gdviewer

[umueller]

Hi there,

I have have an example which makes gdviewer.Clear() (and other MF) go NullPtrEx.

The attached example references the gdviewer from another page without prior displaying it (but it says it's initailized). If the tab with the gdviewer is shown everything works. But just staring up an pressing the button crashes it (but not all functions would crash).


Regards

UM

[Loïc]

Hi,

Could you attach all the project's files?

Kind regards,

Loïc

[umueller]

Hi,

here you go. Hope it's complete.

Regards

[Loïc]

Hi,

You are trying to reach a non loaded element. Please use such code:

Code: Select all

        Dim gdViewer As GdPicture11.WPF.GdViewer = DirectCast(System.Windows.Application.Current.MainWindow, MainWindow).gd.gdViewer
        If gdViewer.IsLoaded Then
            gdViewer.Clear()
        End If

Please let me know if you need further information.

With best regards,

Loïc

[umueller]

Hi,

thank you for the quick answer.

But how can I initialize the gdviewer even if it's wasn't shown before? Suppose I don't want to call 'Clear()' but 'DisplayFromGdPictureImage(pid)' to display an image? For our eval application the user selects a picture and other data and then switches to the page with gdviewer which crashes the app.

Best regards

UM

[Loïc]

Hi,

I guess you can select by code the tab hosting the GdViewer control. In all case the control must be loaded before interacting with it from code behind.

With best regards,

Loïc