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Q83543: DragDrop.exe - Implementing the Drag-Drop Protocol

Article: Q83543
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.1
Operating System(s): 
Keyword(s): kbfile kbsample kb16bitonly _IK kbGrpDSUser kbOSWin310
Last Modified: 05-DEC-1999

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The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) 3.1 
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SUMMARY
=======

Windows 3.1 supports four new functions and one new message that enable an
application to implement the drag-drop protocol. DragDrop.exe is a sample that
demonstrates how to use all four functions and the message. When the user drags
and drops a file onto Dragdrop.exe, the name of the file is added to a list box
in Dragdrop.exe

MORE INFORMATION
================

The following files are available for download from the Microsoft Download
Center:

DragDrop.exe

For additional information about how to download Microsoft Support files, click
the article number below to view the article in the Microsoft Knowledge Base:

  Q119591 How to Obtain Microsoft Support Files from Online Services

Microsoft used the most current virus detection software available on the date of
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servers that prevent any unauthorized changes to the file.


An application that can accept files dragged from the File Manager calls the
DragAcceptFiles function specifying one or more of its windows. When the user
drags a file from the File Manager into the window specified in the
DragAcceptFiles call, and releases the left mouse button, File Manager sends the
application a WM_DROPFILES message. (File Manager sends a WM_DROPFILES message
only to applications that have registered a window with DragAcceptFiles.)

One of the parameters to WM_DROPFILES contains a handle to an internal data
structure. The DragQueryFile function retrieves a number of dropped files and
their names from the data structure and returns this information to the
application. Likewise, DragQueryPoint retrieves the position of the mouse cursor
when the file(s) was dropped.

To release the memory allocated by Windows for the WM_DROPFILES data structure,
the application must call the DragFinish function after it retrieves the
applicable data.

Additional query words:

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Keywords          : kbfile kbsample kb16bitonly _IK kbGrpDSUser kbOSWin310 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK310
Version           : WINDOWS:3.1

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