Drag and drop an image into a RichTextBox

Question

I am updating code done in VB 4, where I have a RichTextBox. I need to be able to drag-and-drop an image from Windows Explorer into the RTB. Unfortunately, I am unable to get the drag-and-drop to work.

I've created a much more simple Windows Form program to try to resolve this, but have made no progress. I begin by setting AllowDrop to True.

Public Sub New()
    InitializeComponent()
    Me.DragAndDropTextBox.AllowDrop = True
End Sub

I then create handlers for the RTB. These are taken directly from MSDN.

Private Sub DragAndDropTextBox_DragEnter(ByVal sender As Object, ByVal e As  _
    System.Windows.Forms.DragEventArgs) Handles DragAndDropTextBox.DragEnter
    ' Check the format of the data being dropped.
    If (e.Data.GetDataPresent(DataFormats.FileDrop)) Then
        ' Display the copy cursor.
        e.Effect = DragDropEffects.Copy
    Else
        ' Display the no-drop cursor.
        e.Effect = DragDropEffects.None
    End If
End Sub

Private Sub DragAndDropTextBox_DragDrop(ByVal sender As Object, ByVal e As  _
    System.Windows.Forms.DragEventArgs) Handles DragAndDropTextBox.DragDrop
    System.Windows.Forms.DragEventArgs) Handles DragAndDropTextBox.DragDrop
    Dim img As Image
    img = Image.FromFile(e.Data.GetData(DataFormats.FileDrop, False))
    Clipboard.SetImage(img)

    Me.DragAndDropTextBox.SelectionStart = 0
    Me.DragAndDropTextBox.Paste()
End Sub

When I grab an image in Explorer and drag it over my window, I get the circle with a slash. I have put breakpoints on the first line of each of the handlers, and they are never reached. I have looked at several pages, and they all seem to give the same process, so I must be missing something simple.

I am not worried right now about pasting the image into the text box; I know I need to work on that. I am only trying to capture the image, but the handler methods do not seem to be getting called.

UPDATE

After quite a bit of experimentation, I found that the actual issue is with my Visual Studio 2010, which I always run as administrator. When I run the program from an exe, the drag-and-drop works. When I try running from VS in debug, it does not. Has anyone experienced this before?

If anyone could shed some light on this, I would be very grateful.

Answer 1

It turned out that the Drag-And-Drop was working when running the code from an exe, but not from within Visual Studio. More searching turned up this answer, which states that Drag-And-Drop does not work in Visual Studio when it is run as an Administrator. I ran it with normal permissions, and the code worked.