Dragging Files From the Windows Explorer

See Also

You can use OLE drag-and-drop to drag files from the Windows Explorer into an appropriate Visual Basic control, or vice versa. For example, you can select a range of text files in the Windows Explorer and then open them all in a single text box control by dragging and dropping them onto the control.

To illustrate this, the following procedure uses a text box control and the OLEDragOver and OLEDragDrop events to open a range of text files using the Files property and the vbCFFiles data format of the DataObject object.

To drag text files into a text box control from the Windows Explorer

1. Start a new project in Visual Basic.
   
   
2. Add a text box control to the form. Set its OLEDropMode property to Manual. Set its MultiLine property to True and clear the Text property.
   
   
3. Add a function to select and index a range of files. For example:

   Sub DropFile(ByVal txt As TextBox, ByVal strFN$)
   Dim iFile As Integer
   iFile = FreeFile
   
   Open strFN For Input Access Read Lock Read _ 
   Write As #iFile
   Dim Str$, strLine$
   While Not EOF(iFile) And Len(Str) <= 32000
   Line Input #iFile, strLine$
   If Str <> "" Then Str = Str & vbCrLf
   Str = Str & strLine
   Wend
   Close #iFile
   
   txt.SelStart = Len(txt)
   txt.SelLength = 0
   txt.SelText = Str
   
   End Sub
   

4. Add the following procedure to the OLEDragOver event. The GetFormat method is used to test for a compatible data format (vbCFFiles).

   Private Sub Text1_OLEDragOver(Data As _ 
   VB.DataObject, Effect As Long, Button As Integer, _ 
   Shift As Integer, X As Single, Y As Single, State _ 
   As Integer)
   If Data.GetFormat(vbCFFiles) Then
   'If the data is in the proper format, _
   inform the source of the action to be taken
   Effect = vbDropEffectCopy And Effect
   Exit Sub
   End If
   'If the data is not desired format, no drop
   Effect = vbDropEffectNone
   
   End Sub
   

5. Finally, add the following procedure to the OLEDragDrop event.

   Private Sub Text1_OLEDragDrop(Data As _ 
   VB.DataObject, Effect As Long, Button As Integer, _ 
   Shift As Integer, X As Single, Y As Single)
   If Data.GetFormat(vbCFFiles) Then
   Dim vFN
   
   For Each vFN In Data.Files
   DropFile Text1, vFN
   Next vFN
   End If
   End Sub
   

6. Run the application, open the Windows Explorer, highlight several text files, and drag them into the text box control. Each of the text files will be opened in the text box.