IDSF::WriteState Method

Article
09/21/2010

The WriteState method writes the public state of the driver that the specified GUID specifies.

Syntax

HRESULT WriteState(
  [in]  DSFStateType Type,
  [in]  BSTR Guid,
  [in]  DSFPropertyBag *pDSFPropertyBag
);

Parameters

Type [in]
The type of state to be written.
Guid [in]
The GUID of the driver whose state is to be written.
pDSFPropertyBag [in]
A pointer to the state to be written.

Return Value

WriteState returns S_OK if the public state is written correctly or E_INVALIDARG if the Type parameter is not a valid DSFDefaultStateType.

This method can also return many standard COM return values.

Remarks

Currently, DSF supports only DSFDefaultStateType as the state type.

Examples

The following C++ code example shows you how to write the public state for a given driver.

HRESULT CMyDevice::WriteSaveState(BSTR bstrGuid, IDSFPropretyBag *piDSFPropertyBag)
{
 DSFStateType Type  = DSFDefaultStateType;
      HRESULT         hr       = S_OK;

     //Read the saved state for this device
 hr = m_piDSFObject->WriteState(Type, bstrGuid, reinterpret_cast<DSFPropertyBag**>(&piDSFPropertyBag));

 return hr;
}

The following VBScript code example shows you how write the public state for a given driver.

Dim PropBag : Set PropBag = CreateObject("DSF.DSFPropertyBag")

' The main DSF object
Dim DSF : Set DSF = CreateObject("DSF.DSF")

' Set the property members so that DriverEntry will fail with STATUS_INSUFFICIENT_RESOURCES
PropBag.Write "DriverEntryStatus", &HC000009A  

' Set the remaining PropertyBag entries for the DSFToaster to STATUS_SUCCESS
PropBag.Write "StartDeviceStatus ", &H00000000
PropBag.Write "AddDeviceStatus", &H00000000 
 
' Write the property bag data
 
DSF.WriteState DSFDefaultStateType,"{9605ee38-896d-4736-9937-bf90a578aca9}", PropBag

Requirements

Header

DSFif.h

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