// 问题3 : filterDeviceObject->StackSize需要加1吗?加1和不加1各有什么意义?
这一句应该是多余的,wdk文档中有这么一句话,This routine sets the AlignmentRequirement in SourceDevice to the value in the next-lower device object and sets the StackSize to the value in the next-lower-object plus one.