I currently have a Windows Forms application that accepts drag and dropped files from other applications. Everything seemed to be working smoothly until we discovered that if we added an email attached to an email, then things got weird.
For example, users had no problem dragging attached jpg or pdf files directly from emails into the application. But when an email (.msg file) was attached to an email, and it was the attached email that was trying to be added to the program, then here's what happens: the following code is able to correctly read the name of the selected attachment that was dragged into the program, but the actual file that is copied is the main containing e-mail (including all the attachments).
Is there any way that I can just pull out the selected/dragged message?
Thanks!!
Here's the entire function:
Public Shared Function HandleFileDrops(ByVal e As System.Windows.Forms.DragEventArgs) As String
' Based on and Borrowed from http://allandynes.com/2015/10/vb-net-drag-and-drop-from-outlook/
Try
If e.Data.GetDataPresent(DataFormats.FileDrop) Then
' We have a file so lets pass it to the calling form
Dim Filename As String() = CType(e.Data.GetData(DataFormats.FileDrop), String())
HandleFileDrops = Filename(0)
ElseIf e.Data.GetDataPresent("FileGroupDescriptor") Then
' We have a embedded file. First lets try to get the file name out of memory
Dim theStream As IO.Stream = CType(e.Data.GetData("FileGroupDescriptor"), IO.Stream)
Dim fileGroupDescriptor(512) As Byte
theStream.Read(fileGroupDescriptor, 0, 512)
Dim fileName As System.Text.StringBuilder = New System.Text.StringBuilder("")
Dim i As Integer = 76
While Not (fileGroupDescriptor(i) = 0)
fileName.Append(Convert.ToChar(fileGroupDescriptor(i)))
System.Math.Min(System.Threading.Interlocked.Increment(i), i - 1)
End While
theStream.Close()
' We should have the file name or if its an email, the subject line. Create our temp file based on the temp path and this info
Dim myTempFile As String = IO.Path.GetTempPath & fileName.ToString
' Look to see if this is a email message. If so save that temporarily and get the temp file.
If InStr(myTempFile, ".msg") > 0 Then
Dim objOL As New Microsoft.Office.Interop.Outlook.Application
Dim objMI As Microsoft.Office.Interop.Outlook.MailItem
If objOL.ActiveExplorer.Selection.Count > 1 Then
MsgBox("You can only drag and drop one item at a time into this screen. Only the first item you selected will be used.", MsgBoxStyle.OkOnly Or MsgBoxStyle.Information, "One Item At A Time")
End If
For Each objMI In objOL.ActiveExplorer.Selection()
objMI.SaveAs(myTempFile)
Exit For
Next
objOL = Nothing
objMI = Nothing
Else
' If its a attachment we need to pull the file itself out of memory
Dim ms As IO.MemoryStream = CType(e.Data.GetData("FileContents", True), IO.MemoryStream)
Dim FileBytes(CInt(ms.Length)) As Byte
' read the raw data into our variable
ms.Position = 0
ms.Read(FileBytes, 0, CInt(ms.Length))
ms.Close()
' save the raw data into our temp file
Dim fs As IO.FileStream = New IO.FileStream(myTempFile, IO.FileMode.OpenOrCreate, IO.FileAccess.Write)
fs.Write(FileBytes, 0, FileBytes.Length)
fs.Close()
End If
' Make sure we have a actual file and also if we do make sure we erase it when done
If IO.File.Exists(myTempFile) Then
' Assign the file name to the add dialog
HandleFileDrops = myTempFile
Else
HandleFileDrops = String.Empty
End If
Else
Throw New System.Exception("An exception has occurred.")
End If
Catch ex As Exception
MsgBox("Could not copy file from memory. Please save the file to your hard drive first and then retry your drag and drop.", MsgBoxStyle.OkOnly Or MsgBoxStyle.Information, "Drag and Drop Failed")
HandleFileDrops = String.Empty
End Try
End Function
This is the section in particular that handles the e-mail:
Dim objOL As New Microsoft.Office.Interop.Outlook.Application
Dim objMI As Microsoft.Office.Interop.Outlook.MailItem
If objOL.ActiveExplorer.Selection.Count > 1 Then
MsgBox("You can only drag and drop one item at a time into this screen. Only the first item you selected will be used.", MsgBoxStyle.OkOnly Or MsgBoxStyle.Information, "One Item At A Time")
End If
For Each objMI In objOL.ActiveExplorer.Selection()
objMI.SaveAs(myTempFile)
Exit For
Next
objOL = Nothing
objMI = Nothing
After really looking at the code that I borrowed from elsewhere on the web, I now see exactly what it does. The section of code that saves Outlook messages creates a new instance of the current Outlook object and then calls that object to pull in its selected items, which will happen to be the main selected email - not the attached email that was dragged over. I was able to add a couple lines of code to do some comparisons on either the email or attachment name to see what was what.
This now works well for my needs:
Dim objOL As New Microsoft.Office.Interop.Outlook.Application
Dim objMI As Microsoft.Office.Interop.Outlook.MailItem
If objOL.ActiveExplorer.Selection.Count > 1 Then
MsgBox("You can only drag and drop one item at a time into this screen. Only the first item you selected will be used.", MsgBoxStyle.OkOnly Or MsgBoxStyle.Information, "One Item At A Time")
End If
'If the message itself has the same name as fileName, then just save the selected MailObject
'Otherwise, iterate through all the attachments to the MailObject and save the one that hase that same name as the fileName
For Each objMI In objOL.ActiveExplorer.Selection()
If objMI.Subject = fileName.ToString() Then
objMI.SaveAs(myTempFile)
Else
Dim objAttach As Microsoft.Office.Interop.Outlook.Attachments = objMI.Attachments
For Each attach As Microsoft.Office.Interop.Outlook.Attachment In objAttach
If attach.FileName = fileName.ToString() Then
attach.SaveAsFile(myTempFile)
End If
Next
End If
Exit For
Next
objOL = Nothing
objMI = Nothing