Drag and drop an image into a RichTextBox - vb.net

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

Try getting rid of the InitializeComponent() call in your Sub New function. When I did that, I was able to detect the DragEnter event. Here is the code I tested (I created a simple WinForm and put a RichTextBox on it called DragAndDropTextBox):
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
DragAndDropTextBox.AllowDrop = True
End Sub
Private Sub DragAndDropTextBox_DragEnter(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles DragAndDropTextBox.DragEnter
Debug.Print("Entering text box region")
' 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
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
End Class
The InitializeComponent() call should appear in your code (I believe) when you add your own custom controls to a form. Otherwise, I don't think you need to call it.

Answer 2

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.