对DriverNetworks中例子有点疑问

请各位看看以下的代码有问题吗？
NDIS_STATUS MyAdapter::Initialize
  (IN OUT KNdisMedium& Medium, IN KNdisConfig& Config)
{
// 1) Fill in the dispatch table
static PDRIVER_DISPATCH MajorFunctions[IRP_MJ_MAXIMUM_FUNCTION+1];

NdisZeroMemory(MajorFunctions, sizeof(MajorFunctions));
MajorFunctions[IRP_MJ_CREATE] =
MajorFunctions[IRP_MJ_CLOSE] =
MajorFunctions[IRP_MJ_CLEANUP] =
MajorFunctions[IRP_MJ_READ] =
MajorFunctions[IRP_MJ_WRITE] =
MajorFunctions[IRP_MJ_DEVICE_CONTROL] = IoDispatch;

// 2) Register the device
NDIS_STATUS Status = NdisMRegisterDevice(
  *KNdisMiniDriver::DriverInstance(),
  KNDIS_STRING_CONST("\\Device\\MyNdisDevice"),
  KNDIS_STRING_CONST("\\DosDevices\\MyNdisDevice"),
  MajorFunctions,
  &m_pDeviceObject,
  &m_DeviceHandle);

. . .
return NDIS_STATUS_SUCCESS;

}

NTSTATUS MyAdapter::IoDispatch (IN PDEVICE_OBJECT DeviceObject, IN PIRP Irp)
{

NTSTATUS Status = STATUS_SUCCESS;
KIrp I(Irp);

switch (I.MajorFunction()) {
  case IRP_MJ_CREATE: // TODO
  case IRP_MJ_CLOSE: // TODO
  case IRP_MJ_CLEANUP: // TODO
  case IRP_MJ_READ: // TODO
  case IRP_MJ_WRITE: // TODO
  case IRP_MJ_DEVICE_CONTROL: // TODO

I.Information() = 0;
break;

default:

Status = STATUS_UNSUCCESSFUL;

};

return I.Complete(Status);

}
这是DriverNetWorks中的一段代码，在Initialize函数中指明了对IRP_MJ_DEVICE_CONTROL:的处理函数IoDispatch，但是在该函数中怎么又能处理IRP_MJ_CREATE等IRP呢？有问题吗？请指教，谢谢！

MajorFunctions[IRP_MJ_CREATE] =
MajorFunctions[IRP_MJ_CLOSE] =
MajorFunctions[IRP_MJ_CLEANUP] =
MajorFunctions[IRP_MJ_READ] =
MajorFunctions[IRP_MJ_WRITE] =
MajorFunctions[IRP_MJ_DEVICE_CONTROL] = IoDispatch;
处理函数都是IoDispatch,而不仅仅是IRP_MJ_DEVICE_CONTROL的处理函数是IoDispatch