Drag N Drop from managed -> unmanaged & vice versa

Our product has implementation both in managed & unmanaged code. So also,
user interface dialogs are both in managed & unmanaged. Currently, I'm
working to support drag & drop across the interop boundaries & am running
into some problems with custom data formats.

So far, I've discovered that if I create a DataObject in managed code for my
custom data format, then on the unmanaged side, I get the DataObject as a
COM object. What is the way to extract the actual data from this COM object?

I've tried various ways to decipher the COM object, including defining my
own unmanaged COM DataObject & calling Marshal.GetObjectForIUnknown to wrap
the unmanaged COM object, but so far I haven't been able to figure out the
proper way to extract my data correctly on the unmanaged end.

I suspect I will run into a similar situation when trying to drag & drop
from an unmanaged dialog to a managed dialog.

I will appreciate any pointers to resolving this problem.

With Regards,

Deepak Malkan
Bentley Systems.

v-phuang
Mon Mar 14 23:36:53 CST 2005

Hi

There is tool DataObject Viewer shipped with VS6.
IDataObject Data Object Viewer
DOBJVIEW displays the list of data formats offered by ActiveX and OLE data
objects created by the Clipboard or drag-and-drop operations.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vsdebug/htm
l/_core_using_viewers_and_spy_programs.asp

You may try to drag the .NET Object onto the tool to see what you will get.

Also can you provide a simple sample which will demostrate what format you
will drag and drop?
Thanks for your understanding!

Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.

Deepak
Tue Mar 15 06:31:49 CST 2005

Peter,

Thank you for your response.

The drag N drop from my object in the managed dialog into DOBJVIEW window
fails.

If I copy my object into the clipboard - using the same dataobject, I get in
DOBJVIEW a list of formats displayed as follows:

System.String
Unknown Clipformat
CF_TEXT
MicroStation Model List

For each format the rest of column are identical - ptr={NULL}, dwAspect =
{Content }, lindex={-1}, tymed={hGlobal}

Of the four formats listed, my program has actually put only two - the first
"System.String" & the last "MicroStation Model List".

My sample code is as follows (in managed C++):

wchar_t * xmlText;
... Allocate & build xmlText ...

NSForms::DataFormats::Format * modelDataFormat =
NSForms::DataFormats::GetFormat(S"MicroStation Model List");
NSForms::DataObject * dataObject = new NSForms::DataObject ();
dataObject->SetData (modelDataFormat->Name, true, new
System::String(xmlText));
dataObject->SetData (new System::String (xmlText));

(NSForms - is a namespace alias for System::Windows::Forms)

- Deepak.


""Peter Huang" [MSFT]" <v-phuang@online.microsoft.com> wrote in message
news:4xBzHESKFHA.1532@TK2MSFTNGXA02.phx.gbl...
> Hi
>
> There is tool DataObject Viewer shipped with VS6.
> IDataObject Data Object Viewer
> DOBJVIEW displays the list of data formats offered by ActiveX and OLE data
> objects created by the Clipboard or drag-and-drop operations.
>
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vsdebug/htm
> l/_core_using_viewers_and_spy_programs.asp
>
> You may try to drag the .NET Object onto the tool to see what you will
get.
>
> Also can you provide a simple sample which will demostrate what format you
> will drag and drop?
> Thanks for your understanding!
>
> Best regards,
>
> Peter Huang
> Microsoft Online Partner Support
>
> Get Secure! - www.microsoft.com/security
> This posting is provided "AS IS" with no warranties, and confers no
rights.
>

Deepak
Tue Mar 15 06:38:51 CST 2005

Peter,

Thank you for your response.

The drag operation from my object in the managed dialog to DOBJVIEW fails.

If I copy my object into the clipboard, then I get the folllowing formats
listed in DOBJVIEW:

System.String
Unknown Clipformat
CF_TEXT
MicroStation Model List

The rest of the columns are identical for all the formats - ptd={NULL},
dwApsect={Content }, lindex={-1}, tymed={hGlobal}.

Of the 4 formats, my program has added only 2 - the first (System.String) &
the last (MicroStation Model List).

My sample code to build the dataObject is as follows (in Managed C++):

wchar_t * xmlText;
... Allocate & build xmlText ...

NSForms::DataFormats::Format * modelDataFormat =
NSForms::DataFormats::GetFormat(S"MicroStation Model List");
NSForms::DataObject * dataObject = new NSForms::DataObject ();
dataObject->SetData (modelDataFormat->Name, true, new System::String
(xmlText));
dataObject->SetData (new System::String (xmlText));

(NSForms is a namespace alias for System::Windows::Forms).

- Deepak.

""Peter Huang" [MSFT]" <v-phuang@online.microsoft.com> wrote in message
news:4xBzHESKFHA.1532@TK2MSFTNGXA02.phx.gbl...
> Hi
>
> There is tool DataObject Viewer shipped with VS6.
> IDataObject Data Object Viewer
> DOBJVIEW displays the list of data formats offered by ActiveX and OLE data
> objects created by the Clipboard or drag-and-drop operations.
>
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vsdebug/htm
> l/_core_using_viewers_and_spy_programs.asp
>
> You may try to drag the .NET Object onto the tool to see what you will
get.
>
> Also can you provide a simple sample which will demostrate what format you
> will drag and drop?
> Thanks for your understanding!
>
> Best regards,
>
> Peter Huang
> Microsoft Online Partner Support
>
> Get Secure! - www.microsoft.com/security
> This posting is provided "AS IS" with no warranties, and confers no
rights.
>

Deepak
Tue Mar 15 14:30:39 CST 2005

Here is some new stuff that I discovered during the course of the day:

What I get on the native side is a "Serialized" form of the System::String
(xmlText) custom object that I set on the DataObject.

What I would like on the native side is an array of wchar_t - i.e. the data
that exactly mimics the xmlText array.

So the question is - how can I get a wchar_t array on the native side?

- Deepak.

"Deepak Malkan [Bentley]" <deepak.malkan@bentley.com> wrote in message
news:OucVvvVKFHA.2132@TK2MSFTNGP14.phx.gbl...
> Peter,
>
> Thank you for your response.
>
> The drag operation from my object in the managed dialog to DOBJVIEW fails.
>
> If I copy my object into the clipboard, then I get the folllowing formats
> listed in DOBJVIEW:
>
> System.String
> Unknown Clipformat
> CF_TEXT
> MicroStation Model List
>
> The rest of the columns are identical for all the formats - ptd={NULL},
> dwApsect={Content }, lindex={-1}, tymed={hGlobal}.
>
> Of the 4 formats, my program has added only 2 - the first (System.String)
&
> the last (MicroStation Model List).
>
> My sample code to build the dataObject is as follows (in Managed C++):
>
> wchar_t * xmlText;
> ... Allocate & build xmlText ...
>
> NSForms::DataFormats::Format * modelDataFormat =
> NSForms::DataFormats::GetFormat(S"MicroStation Model List");
> NSForms::DataObject * dataObject = new NSForms::DataObject ();
> dataObject->SetData (modelDataFormat->Name, true, new System::String
> (xmlText));
> dataObject->SetData (new System::String (xmlText));
>
> (NSForms is a namespace alias for System::Windows::Forms).
>
> - Deepak.
>
> ""Peter Huang" [MSFT]" <v-phuang@online.microsoft.com> wrote in message
> news:4xBzHESKFHA.1532@TK2MSFTNGXA02.phx.gbl...
> > Hi
> >
> > There is tool DataObject Viewer shipped with VS6.
> > IDataObject Data Object Viewer
> > DOBJVIEW displays the list of data formats offered by ActiveX and OLE
data
> > objects created by the Clipboard or drag-and-drop operations.
> >
>
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vsdebug/htm
> > l/_core_using_viewers_and_spy_programs.asp
> >
> > You may try to drag the .NET Object onto the tool to see what you will
> get.
> >
> > Also can you provide a simple sample which will demostrate what format
you
> > will drag and drop?
> > Thanks for your understanding!
> >
> > Best regards,
> >
> > Peter Huang
> > Microsoft Online Partner Support
> >
> > Get Secure! - www.microsoft.com/security
> > This posting is provided "AS IS" with no warranties, and confers no
> rights.
> >
>
>

v-phuang
Wed Mar 16 01:54:13 CST 2005

Hi

It seems that what you want is to drag the text (xmlText) from .NET app to
a unmanaged Application.
Here is two link about the drag&drop.
//Managed
Performing Drag-and-Drop Operations in Windows Forms
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vbcon/html/
vbtskStartingDragOperations.asp

//Unmanaged
Using MFC OLE Drag and Drop to Drag Text Between Windows
http://support.microsoft.com/?id=135299

After I drag the button1 from the managed to the trashicon on the unmanaged
one, I can get the contenct("button1") from the pData in the function below.
BOOL COleDropWndTarget::OnDrop(CWnd* pWnd, COleDataObject* pDataObject,
DROPEFFECT dropEffect, CPoint point )

You may have a try to see if that meet your request.
Thanks!

BTW: after I do the drag and drop from the managed to the dataobject view
tool, I can get three item displayed.

Best regards,

Peter Huang
Microsoft Online Partner Support

Get Secure! - www.microsoft.com/security
This posting is provided "AS IS" with no warranties, and confers no rights.