如何在文件操作完成之前延迟vb.net程序？

I have this:

我有这个:

    Dim myTemp As String
    myTemp = System.DateTime.Now().ToString("MMMddyyyy_HHmmss") & ".pdf"

    System.IO.File.Copy(myFile, "c:\" & myTemp)
    Application.DoEvents()
    OpenFile(myTemp)
    Dim myTemp As String