GET PAST FILEDROP REGISTER SCREEN HOW TO
GET PAST FILEDROP REGISTER SCREEN DOWNLOAD
GET PAST FILEDROP REGISTER SCREEN WINDOWS

The WPARAM of a WM_DROPFILES message is an HDROP that lists what files are being dropped. When you drag files or folders from an Explorer window and drop them in your window, the window receives a WM_DROPFILES message. No matter which of the two methods you use, your window becomes a drop target. If your main window is a CView instead of a dialog, you'll need to set this style at runtime. The first is your main window handle, and the second is TRUE to indicate you can accept drag and drop. If you want to set this style at runtime, call the DragAcceptFiles() API, which takes two parameters. For dialogs, this is on the 'Extended Styles' page, as shown here: To use the old method, you first set the 'accept files' style in your window. The other way is to register your window as an OLE drop target.

GET PAST FILEDROP REGISTER SCREEN WINDOWS

The first way is a holdover from Windows 3.1 and uses the WM_DROPFILES message. There are two ways for your window to accept drag and drop. Accepting a drag and drop from ExplorerĪccepting a drag and drop is much easier than initiating one, so I'll cover accepting first. The only other member that's used in drag and drop is fWide, which indicates whether the filenames are in ANSI or Unicode characters. But where is it stored? It is actually stored right after the fWide member, and pFiles holds the offset (relative to the beginning of the struct) where the list is located in memory. The list is formatted as a double-null terminated list of strings. The one thing that isn't listed in the struct definition is the list of filenames. Here is its definition:īOOL fNC // is it on NonClient area and pt is in screen coords There's also the HDROP type, which is simply a pointer to a DROPFILES struct.ĭROPFILES isn't a very complex structure. So what exactly is the CF_HDROP format? It turns out that it's just a DROPFILES struct. So, what's contained in that CF_HDROP format? Read on. Similarly, if we can fill a data object with CF_HDROP data, Explorer will let our app be a drag source.

GET PAST FILEDROP REGISTER SCREEN HOW TO

If we write an app that registers its window as a drop target, and if we know how to read CF_HDROP data, we'll be able to accept dropped files. The other formats are custom formats registered by Explorer for its own use. If you check out the data contained in the IDataObject with a viewer like ClipSpy, you'll see that Explorer puts several data formats in the data object: The window you drag into (the drop target), then reads that data using IDataObject methods that's how it knows what files are being dropped. When you begin a drag operation, the Explorer window you drag from (the drop source), creates a COM object implementing the IDataObject interface, and puts some data into the object. Drag and Drop with ExplorerĪs you know, Explorer lets you drag files among Explorer windows and the desktop. You can then drag files back out to Explorer windows, using the Shift or Ctrl keys to tell Explorer to move or copy the original files, respectively. You can drag any number of files into MultiFiler, and it shows them all in a list. The program is MultiFiler, a little utility that acts like a drag and drop 'staging area'. If you need help with COM objects and interfaces, check out my Intro to COM article. The sample project is an MFC app, and the article assumes you're familiar with C++, MFC, and using COM objects and interfaces. In this article, I demonstrate how to hook up drag and drop so your program can accept drops from an Explorer window, and be a drag source so your users can drag files into an Explorer window. Like many things in Windows, it seems easy once you know how it's done, but finding the answer can be quite a chore. I've seen several questions around the CodeProject boards lately asking about doing drag and drop between a program and Explorer windows.

GET PAST FILEDROP REGISTER SCREEN DOWNLOAD

Download demo project (MultiFiler program) - 54.9 Kb.

Get past filedrop register screen