批量打印excel的一段代码，F8能打印出列表中所有excel文件，为何F5只能打印一张？

Private Sub Command3_Click()
     Dim RetVal As Long
     Dim ShExInfo As SHELLEXECUTEINFO
     
     Dim I As Integer
     Dim Mypathname As String
     For I = 0 To List1.ListCount - 1
             Mypathname = List1.List(I)

             With ShExInfo
                 .cbSize = Len(ShExInfo)
                 .fMask = &H40
                 .hwnd = 0
                 .lpVerb = "print"
                 .lpFile = Mypathname
                 .lpParameters = ""
                 .lpDirectory = vbNullChar
                 .nShow = 0
             End With
            
             RetVal = ShellExecuteEx(ShExInfo)
            
             If RetVal = 0 Then
                 Exit Sub
             End If
     Next
 End Sub


 Public Type SHELLEXECUTEINFO
      cbSize As Long
      fMask As Long
      hwnd As Long
      lpVerb As String
      lpFile As String
      lpParameters As String
      lpDirectory As String
      nShow As Long
      hInstApp As Long
      lpIDList As Long
      lpClass As String
      hkeyClass As Long
      dwHotKey As Long
      hIcon As Long
      hProcess As Long
  End Type