Weiji, You can try this: //dispatch function extern "C" NTSTATUS PCP_Create ( PDEVICE_OBJECT DeviceObject, PIRP Irp ) { NTSTATUS ntStatus = STATUS_UNSUCCESSFUL; ASSERT(DeviceObject); ASSERT(Irp); if( check this is the object created by you) { ntStatus = STATUS_SUCCESS; } else { ntStatus = PcDispatchIrp( DeviceObject,Irp ); } return ntStatus; } But you have to take care in close file handler and clean up handler. Bcs here you are blindly return success for your application call. So none of the file related IRP from application should be dispatched to portcls. Hope it will help you Regards Vargheese _____ From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@freelists. org] On Behalf Of Weiji Zheng Sent: Thursday, July 20, 2006 11:58 AM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] 回复: Re: for help in implementation virtual audio driver hi, Vargheese actaully, my own application can open the MSVAD if I modify code in IRP_MAJOR_CREATE as following: //dispatch function extern "C" NTSTATUS PCP_Create ( IN PDEVICE_OBJECT pDeviceObject, IN PIRP pIrp ) { PIO_STACK_LOCATION IrpStack = IoGetCurrentIrpStackLocation(pIrp); NTSTATUS ntStatus = STATUS_SUCCESS; pIrp->IoStatus.Status = STATUS_SUCCESS; pIrp->IoStatus.Information = 0; IoCompleteRequest(pIrp, IO_NO_INCREMENT); return STATUS_SUCCESS; } but Graph Edit DOES not open the MSVAD(simple) because adapter driver does not dispatch IRP to PortCIs driver. Regards, --weiji zheng Vargheese Baby <vargheese.baby@xxxxxxxxxxxxxxx> 写道: Hi Weiji, I tried “IoRegisterDeviceInterface()” with MSVAD. Its not working for me. The following method will help you. In DriverEntry First call PcInitializeAdapterDriver Then assign your dispatch routines In AddDevice IoCreateDevice IoCreateSymbolicLink In Application Open the handle by CreateFile() Regards Vargheese _____ From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@freelists. org] On Behalf Of Weiji Zheng Sent: Thursday, July 20, 2006 10:19 AM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] for help in implementation virtual audio driver Hi I am developing one project, that is, PCM data is transfered into MSVAD by usr mode, and MSVAD then put these PCM data into another application based on DirectSound, such as Skype, that means MSVAD will be open simultaneously both the applications. Actaully, I encounter the same question as following: 1. how can I get the handle of the MSVAD(Simple)? 2. I tried to use IoRegisterDeviceInterface() in AddDevice() of MSVAD(Simple), and then in my user mode application I use SetupDiGetDeviceInterfaceDetail() and CreateFile() to get the handle of the MSVAD device. It seems that I can get the handle of the MSVAD(Simple), but the Graph Edit con not find any device about MSVAD, Do you have any idea about this? Maybe the implementation in IRP_MAJOR_CREATE is one key. //dispatch function extern "C" NTSTATUS PCP_Create ( IN PDEVICE_OBJECT pDeviceObject, IN PIRP pIrp ) { PIO_STACK_LOCATION IrpStack = IoGetCurrentIrpStackLocation(pIrp); //PDEVICE_EXTENSION pDevExt = (PDEVICE_EXTENSION)pDeviceObject->DeviceExtension; NTSTATUS ntStatus = STATUS_SUCCESS; DPF(D_TERSE, ("[enter PCP_Create]")); DbgPrint("the Flags is 0x%x\n", pIrp->Flags); DbgPrint("the RequestorMode is 0x%x\n", pIrp->RequestorMode); if(pIrp->RequestorMode == 0x1) //my own application {// Complete successfully pIrp->IoStatus.Status = STATUS_SUCCESS; pIrp->IoStatus.Information = 0; IoCompleteRequest(pIrp, IO_NO_INCREMENT); return STATUS_SUCCESS; } else //Graph Edit { // // Pass the IRPs on to PortCls // ntStatus = PcDispatchIrp( pDeviceObject, pIrp ); if(NT_SUCCESS(ntStatus)) DbgPrint("success to open device\n"); else DbgPrint("fail to open device\n"); return ntStatus; } } But when I run own application(not Graph Edit), the system crash! so would you please give me some advice. thanks for any help. best regards --weiji zheng _____ <http://cn.mail.yahoo.com/> 雅虎免费邮箱-3.5G容量,20M附件 _____ <http://cn.mail.yahoo.com> 雅虎1G免费邮箱百分百防垃圾信