Help on strange droping issue

Question

Dear all,

Long time have not been here and now I am back again.

I met a strange issue while droping a Scatterview Item on top of a LibraryContainer which bind to a colection of Pictures.

I have a LibraryContainer defined as follow :

<s:LibraryContainer x:Name="SurfaceContainer" Tag="Presentation" Background="WhiteSmoke"
              ItemsSource="{Binding Path=PictureCollection}" CanSwitchViewingMode="False" />

This container is part of a SurfaceUserControl

When my app start, I add to the main application scaterrview, a single scattervieItem which is bind to a picture path and then I add also to same scatterview the SurfaceUSerCOntrol containing my LibraryContainer binds to a PictureCollection

If I drag and drop an item from the library container to the surface and reverse, it works fine.

If I drag the simple scatterview  item pointing to a picture path, on top of the the LibraryContainer, then I get a TargetInvocationException saying:
"{"The cursor data dropped to LibraryStack cannot be null."}"

IF I handle the exception in app.xamal.c in Application_DispatcherUnhandledException, my application did not crashed but the scatterview item beeing droped gets removed.

Any idea how to solve this ?

In fact, I do not want any other scatterview item beeing drop in LIbrary container if there was not previously in the stack.

I have check some msdn info about this but did not help

Thanks

Serge

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Answer 1

Hello Serge,

Can you please high light the root cause and how to over come this issue.

Answer 2

sorry this was an old post that i solve already for a long time

I had to register to the On  Query target of the control and check if the type of data is allowed to be dropped

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Your knowledge is enhanced by that of others.