问VB .NET Outlook 2016加载项主题行

EN

Private Sub Button1_Click(sender As Object, e As RibbonControlEventArgs) Handles Button1.Click
    ' Get the Application object
    Dim application As Outlook.Application = Globals.ThisAddIn.Application

    ' Get the active Inspector object and check if is type of MailItem
    Dim inspector As Outlook.Inspector = application.ActiveInspector()
    Dim mailItem As Outlook.MailItem = TryCast(inspector.CurrentItem, Outlook.MailItem)
    If mailItem IsNot Nothing Then
        If mailItem.EntryID Is Nothing Then
            If Not IsNothing(mailItem.Subject) AndAlso ((mailItem.Subject.Contains(" unencrypt")) OrElse (mailItem.Subject.Contains("unencrypt "))) Then
                mailItem.Subject = mailItem.Subject
            'ElseIf IsNothing(mailItem.Subject) Then
                'System.Threading.Thread.Sleep(20000)
                'mailItem.Subject = mailItem.Subject + " unencrypt"
            Else
                mailItem.Subject = mailItem.Subject + " unencrypt"
            End If
            If Not IsNothing(mailItem.To) AndAlso mailItem.To.ToString().Trim <> "" Then
                mailItem.Send()
            Else
                MessageBox.Show("We need to know who to send this to. Make sure you enter at least one name.", "Microsoft Outlook", MessageBoxButtons.OK, MessageBoxIcon.Exclamation, MessageBoxDefaultButton.Button1)
            End If
        End If
    End If
End Sub

<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function FindWindowEx(ByVal parentHandle As IntPtr, _
                                        ByVal childAfter As IntPtr, _
                                        ByVal lclassName As String, _
                                        ByVal windowTitle As String) As IntPtr
End Function
<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function FindWindow(ByVal lclassName As String, _
                                    ByVal lWindowName As String) As IntPtr
End Function
<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function GetWindowText(ByVal hWnd As IntPtr, _
                                        ByVal lpString As StringBuilder, _
                                        ByVal nMaxCount As Integer) As Integer
End Function
<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function GetWindowTextLength(ByVal hwnd As IntPtr) As Integer
End Function

Private Function GetSubject(inspector As Outlook.Inspector) As String
    Try
        Dim inspectorHandle As IntPtr = FindWindow("rctrl_renwnd32", inspector.Caption)
        Dim windowLevel2Handle As IntPtr = FindWindowEx(inspectorHandle, IntPtr.Zero, "AfxWndW", "")
        Dim windowLevel3Handle As IntPtr = FindWindowEx(windowLevel2Handle, IntPtr.Zero, "AfxWndW", "")
        Dim windowLevel4Handle As IntPtr = FindWindowEx(windowLevel3Handle, IntPtr.Zero, "#32770", "")
        Dim SubjectHandle As IntPtr = FindWindowEx(windowLevel4Handle, IntPtr.Zero, "Static", "S&ubject")
        Dim SubjectTextBoxHandle As IntPtr = FindWindowEx(windowLevel4Handle, SubjectHandle, "RichEdit20WPT", "")
        Dim length As Integer = GetWindowTextLength(SubjectTextBoxHandle)
        Dim sb As New StringBuilder(length + 1)
        GetWindowText(SubjectTextBoxHandle, sb, sb.Capacity)

        Return sb.ToString()
    Catch
        Return ""
    End Try

End Function