Object reference not set to an instance of an object

场景：Object reference not set to an instance of an object解决方案

Object reference not set to an instance of an object
大家好，向各位请下面这问题，希望能得到解达。非常感谢。
  Structure ZIPnames
  Public zFiles As String()
  End Structure
  
  Private zZipFileNames as ZIPName = new ZIPNames

  Public Sub AddFile(ByRef FileName As Object)

  zargc = zargc + 1
  zZipFileNames.zFiles(zargc - 1) = FileName
  End Sub

 call AddFile(m_FileNameInDir) 报下述错误，Object reference not set to an instance of an object。

------解决方案--------------------
错误是有对象指向错误，看看是不是有不能访问的对象