I tried using a timer to solve this problem, but I still want to know if there is a more direct way
import c4d 
import threading
from c4d.gui import GeUserArea, GeDialog
GADGET_ID_GEUSERAREA = 10000
class DropArea(GeUserArea):
    def __init__(self):
        # Used to store all objects involved in the drag-and-drop operation
        self.currentDragObjects = []
        # Flag to indicate whether a drag operation is in progress
        self.isDragging = False
        # Define a timer to delay the handling of the drag completion
        self.dragTimer = None
    def Message(self, msg, result):
        # Handle drag-and-drop messages
        if msg.GetId() == c4d.BFM_DRAGRECEIVE:
            # Check if the drag was lost or canceled
            if msg.GetInt32(c4d.BFM_DRAG_LOST) or msg.GetInt32(c4d.BFM_DRAG_ESC):
                self.isDragging = False
                return self.SetDragDestination(c4d.MOUSE_FORBIDDEN)
            # If the drag just started, clear the previous object list
            if not self.isDragging:
                self.currentDragObjects = []  # Initialize the storage list
                self.isDragging = True  # Mark the beginning of the drag
            # Verify if it is a valid drop area
            if not self.CheckDropArea(msg, True, True):
                return self.SetDragDestination(c4d.MOUSE_FORBIDDEN)
            # Get the dragged file object
            dragInfo = self.GetDragObject(msg)
            if dragInfo is not None:
                dragObject = dragInfo['object']
                # Check if the object already exists in the list to avoid duplicates
                if dragObject not in self.currentDragObjects:
                    self.currentDragObjects.append(dragObject)
            # Reset the timer to delay the handling of drag completion
            if self.dragTimer is not None:
                self.dragTimer.cancel()
            # Set a short timer (e.g., 0.2 seconds) to determine if the drag operation is complete
            self.dragTimer = threading.Timer(0.2, self._finalize_drag)
            self.dragTimer.start()
            # Set the mouse cursor to a valid state
            return self.SetDragDestination(c4d.MOUSE_MOVE)
        # Call the base class Message() method to handle other messages
        return c4d.gui.GeUserArea.Message(self, msg, result)
    def _finalize_drag(self):
        # Delayed execution to ensure all dragged objects have been received
        self.isDragging = False
        if self.currentDragObjects:
            # Print all dropped files
            print(f"Dropped files: {self.currentDragObjects}")
            # Additional logic can be executed here, e.g., handling file paths or other content
            # Clear the object list for the next drag-and-drop operation
            self.currentDragObjects = []
        # Redraw the user area (if UI update is needed)
        self.Redraw()
class ExampleDialog(GeDialog):
    geUserArea = DropArea()
    def CreateLayout(self):
        self.SetTitle("Drag Area")
        if self.GroupBegin(0, c4d.BFH_SCALEFIT | c4d.BFV_SCALEFIT, cols=1, rows=0, title="", groupflags=0, initw=100, inith=100):
            self.GroupBorderSpace(8, 8, 8, 8)
            self.GroupSpace(2, 2)
            # Add the user area gadget
            self.AddUserArea(GADGET_ID_GEUSERAREA, c4d.BFH_SCALEFIT | c4d.BFV_SCALEFIT, 200, 200)
            # Attach the user area to the gadget
            self.AttachUserArea(self.geUserArea, GADGET_ID_GEUSERAREA)
        self.GroupEnd()
        return True
if __name__ == "__main__":
    global dlg
    dlg = ExampleDialog()
    dlg.Open(dlgtype=c4d.DLG_TYPE_ASYNC, defaultw=200, defaulth=200)