VB.NET Drag Drop Error

[mikeg71]

Hi All... I am using the code below to drag&drop files between listboxes. For some reason I am now getting an exception 'Value Cannot be Null. Parameter Name: item'. When I use: 'If result = DialogResult.Yes' and attempt to SPLIT the job (which is only renaming the file and moving a copy) this is where the error happens and I am not certain why. The file does move, but does not get to the append to file portion. I am stuck here on this as I don't really understand the error.

*** EDIT: Just realized the .Tag property was incorrect in that portion of the code. I still think this needs more efficiency added. Please feel free to add any comments.

Private Sub ListBoxes_DragDrop(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles ListBox6.DragDrop, ListBox5.DragDrop, ListBox4.DragDrop, ListBox3.DragDrop, ListBox2.DragDrop, ListBox1.DragDrop, ListBox7.DragDrop


        Try
            If e.Data.GetDataPresent(GetType(FileInfo)) Then

                With DirectCast(sender, ListBox)

                    Dim NewFile As String
                    Dim fileDropped As FileInfo = DirectCast(e.Data.GetData(GetType(FileInfo)), FileInfo)
                    Dim FileToMove As String = fileDropped.FullName
                    Dim MoveLocation As String = strPath & "\" & CStr(.Tag) & "\" & fileDropped.Name


                    If sender IsNot ListBox7 OrElse (sender Is ListBox7 AndAlso .Items.Count = 0) Then
                        blocked = False
                    Else
                        MsgBox("Only one job at a time can be running!" & vbCrLf & vbCrLf & "Move first job from Queue before continuing.", vbCritical, "")
                        blocked = True
                    End If


                    If CStr(.Tag) = "SMT-Complete" Then

                        If CmbMoveTo.SelectedIndex = -1 Then
                            MsgBox("Select a 'Move To' location from the drop down list!", vbExclamation, "Error")
                            Exit Sub
                        Else
                            MoveLocation = strPath & "\" & CmbMoveTo.SelectedItem & "\" & fileDropped.Name
                        End If

                        Dim result As DialogResult = MessageBox.Show("Do you want to split this job?", "Job Split", MessageBoxButtons.YesNoCancel)

                        If result = DialogResult.Yes Then
                            NewFile = InputBox("Enter the quantity you are moving to: " & vbCrLf & vbCrLf & CStr(.Tag), "Update", fileDropped.Name)

                            If NewFile.Contains("__SPLIT") Then
                                MoveLocation = strPath & "\" & CStr(CmbMoveTo.SelectedValue) & "\" & NewFile
                            Else
                                MoveLocation = strPath & "\" & CStr(CmbMoveTo.SelectedValue) & "\" & NewFile & "__SPLIT"
                            End If

                            File.Copy(FileToMove, MoveLocation)
                            DirectCast(sender, ListBox).Items.Add(New DirectoryInfo(strPath & "\" & CStr(.Tag)).GetFiles.Where(Function(fi) fi.FullName = MoveLocation).FirstOrDefault)
                            Try
                                Using sw As New StreamWriter(File.Open(MoveLocation, FileMode.OpenOrCreate))
                                    sw.WriteLine("Moved To," & CStr(CmbMoveTo.SelectedValue) & "," & DateTime.Now & "," & NewFile & ",Job Split")
                                End Using
                            Catch ex As Exception
                                MsgBox("File Update Error!" & vbCrLf & ex.Message)
                            End Try

                        ElseIf result = DialogResult.Cancel OrElse result = DialogResult.No Then

                            File.Move(FileToMove, MoveLocation)
                            .Items.Add(New DirectoryInfo(strPath & "\" & CmbMoveTo.SelectedValue).GetFiles.Where(Function(fi) fi.FullName = MoveLocation).FirstOrDefault)

                            Try
                                Using sw As New StreamWriter(File.Open(MoveLocation, FileMode.Append))
                                    sw.WriteLine("Moved To," & CmbMoveTo.SelectedValue & "," & DateTime.Now & "," & fileDropped.Name)
                                End Using
                            Catch ex As Exception
                                MsgBox("File Update Error!" & vbCrLf & ex.Message)
                            End Try
                        End If

                    Else
                        File.Move(FileToMove, MoveLocation)
                        .Items.Add(New DirectoryInfo(strPath & "\" & CStr(.Tag)).GetFiles.Where(Function(fi) fi.FullName = MoveLocation).FirstOrDefault)

                        Try
                            Using sw As New StreamWriter(File.Open(MoveLocation, FileMode.Append))
                                sw.WriteLine("Moved To," & CStr(.Tag) & "," & DateTime.Now & "," & fileDropped.Name)
                            End Using
                        Catch ex As Exception
                            MsgBox("File Update Error!" & vbCrLf & ex.Message)
                        End Try
                    End If
                End With
            End If
        Catch ex As Exception
            MsgBox("Duplicate Job Detected... " & ex.Message, vbExclamation, "File Error")
        End Try


    End Sub