主题：窗口CurrentChanged事件

窗口CurrentChanged事件中写入下面代码，为什么只执行红色部分代码？

If e.Table.Current Is Nothing Then '如果Current为Nothing
    Return
Else
    '''显示或关闭菜单按钮
    For Each dr As Row In CurrentTable.Rows
        Dim sit As WinForm.StripItem = e.Form.Strips("主菜单").Items("txbf")
        Dim ns As Integer = DataTables("图像明细").Compute("Count([_Identify])","图像编号 = '" & dr("附件编号") & "'")
        If ns > 0 Then
            sit.Enabled = True
        Else
            sit.Enabled = False
            Return
        End If
       
        Dim pstr As WinForm.StripItem = e.Form.Strips("主菜单").Items("Pdf_open")
        Dim pfil As String = "文件名称 = '" & dr("文件名称") & "' And 文件附件编号 = '" & dr("附件编号") & "' And 文件后缀 = '.pdf'"
        Dim pcnt As Integer = DataTables("资料明细").Compute("Count([_Identify])",pfil)
        If pcnt > 0 Then
            pstr.Enabled = True
        Else
            pstr.Enabled = False
        End If
       
       
        Dim wstr As WinForm.StripItem = e.Form.Strips("主菜单").Items("Word_open")
        Dim wfil As String = "文件名称 = '" & dr("文件名称") & "' And 文件附件编号 = '" & dr("附件编号") & "' And 文件后缀 = '.doc'"
        Dim wcnt As Integer = DataTables("资料明细").Compute("Count([_Identify])",wfil)
        If wcnt > 0 Then
            wstr.Enabled = True
        Else
            wstr.Enabled = False
        End If
    Next
End If