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Exploring Delphi XE3 – WinApi Additions – Winapi.Functiondiscovery Part 1

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Starting with Windows Vista The SetupDi and the WMI are not longer the only APIs to enumerate devices and receive notifications about hardware changes, with the introduction of the Function Discovery API you can access the installed devices using a unified API and interfaces for gathering functionality, properties, and notifications from various device types like PnP, PnP-X, Registry, NetBIOS and custom (third-party) providers.

Delphi XE3 include the translation of the headers for the Function Discovery API in the Winapi.Functiondiscovery unit. In this post I will show the basic code to enumerate the hardware devices.

To get a collection of the devices (function instances), you must use use the IFunctionDiscovery.GetInstanceCollection method. from here to get each function instance in the collection in order, use the IFunctionInstanceCollection.Item method and finally use the IFunctionInstance.OpenPropertyStore and IPropertyStore.GetValue methods to retrieve the value of each property.

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.Win.ComObj,
  Winapi.Windows,
  Winapi.Activex,
  Winapi.PropSys,
  Winapi.Functiondiscovery,
  System.SysUtils;

procedure Enumerate;
var
    LFunctionDiscovery : IFunctionDiscovery;
    hr : HResult;
    i : integer;
    LFunctionInstance : IFunctionInstance;
    ppIFunctionInstanceCollection : IFunctionInstanceCollection;
    ppIPropertyStore  : IPropertyStore;
    pv : TPropVariant;
    pdwCount : DWORD;
    pszCategory: PWCHAR;
begin
  //create an instance to the  IFunctionDiscovery interface
  LFunctionDiscovery := CreateComObject(CLSID_FunctionDiscovery) as IFunctionDiscovery;
  try
    //set the provider to search
    pszCategory:=FCTN_CATEGORY_PNP;
    //get the devices collection
    hr := LFunctionDiscovery.GetInstanceCollection(pszCategory, nil, true, ppIFunctionInstanceCollection);
      //get the collection count
      if Succeeded(hr) and Succeeded(ppIFunctionInstanceCollection.GetCount(pdwCount)) then
      begin
        if pdwCount=0 then
          Writeln(Format('No items was found for the %s category',[pszCategory]))
        else
        for i := 0 to pdwCount - 1 do begin
          //get the n Item of the collection
          if Succeeded(ppIFunctionInstanceCollection.Item(i, LFunctionInstance)) then
          begin
            //init the propertiess store
            LFunctionInstance.OpenPropertyStore(STGM_READ, ppIPropertyStore);
            //read the properties values
            if Succeeded(ppIPropertyStore.GetValue(PKEY_NAME, pv)) then
             Writeln(Format('Name          %s',[pv.pwszVal]));
            if Succeeded(ppIPropertyStore.GetValue(PKEY_Device_InstanceId, pv)) then
             Writeln(Format('Instance Id   %s',[pv.pwszVal]));
            if Succeeded(ppIPropertyStore.GetValue(PKEY_Device_Driver, pv)) then
             Writeln(Format('Device Driver %s',[pv.pwszVal]));
            if Succeeded(ppIPropertyStore.GetValue(PKEY_Device_Model, pv)) then
             Writeln(Format('Model         %s',[pv.pwszVal]));
            if Succeeded(ppIPropertyStore.GetValue(PKEY_Device_Manufacturer, pv)) then
             Writeln(Format('Manufacturer  %s',[pv.pwszVal]));
            if Succeeded(ppIPropertyStore.GetValue(PKEY_Device_LocationInfo, pv)) then
             Writeln(Format('Location      %s',[pv.pwszVal]));
            Writeln;
          end
          else
           RaiseLastOSError;
        end;
      end
      else
       RaiseLastOSError;
  finally
    LFunctionDiscovery:=nil;
  end;
end;

begin
 try
   if (Win32MajorVersion >= 6) then  // available on Vista (or later)
   begin
    if Succeeded(CoInitializeEx(nil, COINIT_MULTITHREADED)) then
    try
     Enumerate;
    finally
      CoUninitialize;
    end;
   end
   else
   Writeln('Windows version not compatible');
 except
    on E:Exception do
        Writeln(E.Classname, ':', E.Message);
 end;
 Writeln('Press Enter to exit');
 Readln;
end.

As you can see the code is very straightforward, Now the next sample show how retrieves all the properties of each device.

{$APPTYPE CONSOLE}

{$R *.res}

uses
  System.Win.ComObj,
  Winapi.Windows,
  Winapi.Activex,
  Winapi.PropSys,
  Winapi.Functiondiscovery,
  System.Generics.Collections,
  System.SysUtils;

procedure Enumerate2;
var
    LFunctionDiscovery : IFunctionDiscovery;
    hr : HResult;
    i,j : integer;
    LFunctionInstance : IFunctionInstance;
    ppIFunctionInstanceCollection : IFunctionInstanceCollection;
    ppIPropertyStore  : IPropertyStore;
    pv : TPropVariant;
    pdwCount : DWORD;
    cProps: DWORD;
    pszCategory: PWCHAR;
    pkey: TPropertyKey;
    ListKeys : TDictionary<TPropertyKey, string>;
    KeyName : string;
begin
  //create a list with TPropertyKey descriptions
  ListKeys:=TDictionary<TPropertyKey, string>.Create;
  try
    ListKeys.Add(PKEY_NAME, 'Name');
{ Device properties }
{ These PKEYs correspond to the old setupapi SPDRP_XXX properties }
    ListKeys.Add(PKEY_Device_DeviceDesc, 'Device Desc');
    ListKeys.Add(PKEY_Device_HardwareIds, 'Hardware Id');
    ListKeys.Add(PKEY_Device_CompatibleIds, 'Compatible Id');
    ListKeys.Add(PKEY_Device_Service, 'Device Service');
    ListKeys.Add(PKEY_Device_Class, 'Class');
    ListKeys.Add(PKEY_Device_ClassGuid, 'Class GUID');
    ListKeys.Add(PKEY_Device_ConfigFlags, 'ConfigFlags');
    ListKeys.Add(PKEY_Device_Manufacturer, 'Manufacturer');
    ListKeys.Add(PKEY_Device_FriendlyName, 'Friendly Name');
    ListKeys.Add(PKEY_Device_LocationInfo, 'Location Info');
    ListKeys.Add(PKEY_Device_PDOName, 'PDO Name');
    ListKeys.Add(PKEY_Device_Capabilities, 'Capabilities');
    ListKeys.Add(PKEY_Device_UINumber, 'UI Number');
    ListKeys.Add(PKEY_Device_UpperFilters, 'Upper Filters');
    ListKeys.Add(PKEY_Device_LowerFilters, 'Lower Filters');
    ListKeys.Add(PKEY_Device_BusTypeGuid, 'Bus Type Guid');
    ListKeys.Add(PKEY_Device_LegacyBusType, 'Legacy Bus Type');
    ListKeys.Add(PKEY_Device_BusNumber, 'Bus Number');
    ListKeys.Add(PKEY_Device_EnumeratorName, 'Enumerator Name');
    ListKeys.Add(PKEY_Device_Security, 'Security');
    ListKeys.Add(PKEY_Device_SecuritySDS, 'Security SDS');
    ListKeys.Add(PKEY_Device_DevType, 'Dev Type');
    ListKeys.Add(PKEY_Device_Exclusive, 'Exclusive');
    ListKeys.Add(PKEY_Device_Characteristics, 'Characteristics');
    ListKeys.Add(PKEY_Device_Address, 'Address');
    ListKeys.Add(PKEY_Device_UINumberDescFormat, 'UI Number Desc. Format');
    ListKeys.Add(PKEY_Device_PowerData, 'Power Data');
    ListKeys.Add(PKEY_Device_RemovalPolicy, 'Removal Policy');
    ListKeys.Add(PKEY_Device_RemovalPolicyDefault, 'Removal Policy Default');
    ListKeys.Add(PKEY_Device_RemovalPolicyOverride, 'Removal Policy Override');
    ListKeys.Add(PKEY_Device_InstallState, 'Install State');
    ListKeys.Add(PKEY_Device_LocationPaths, 'Location Paths');
    ListKeys.Add(PKEY_Device_BaseContainerId, 'BaseContainer Id');
{ Device properties }
{ These PKEYs correspond to a device's status and problem code }

    ListKeys.Add(PKEY_Device_DevNodeStatus, 'Dev Node Status');
    ListKeys.Add(PKEY_Device_ProblemCode, 'Problem Code');
{ Device properties }
{ These PKEYs correspond to device relations }

    ListKeys.Add(PKEY_Device_EjectionRelations, 'Ejection Relations');
    ListKeys.Add(PKEY_Device_RemovalRelations, 'Removal Relations');
    ListKeys.Add(PKEY_Device_PowerRelations, 'Power Relations');
    ListKeys.Add(PKEY_Device_BusRelations, 'Bus Relations');
    ListKeys.Add(PKEY_Device_Parent, 'Parent');
    ListKeys.Add(PKEY_Device_Children, 'Children');
    ListKeys.Add(PKEY_Device_Siblings, 'Sibling');
    ListKeys.Add(PKEY_Device_TransportRelations, 'Transport Relations');
{ Other Device properties }
    ListKeys.Add(PKEY_Device_Reported, 'Reported');
    ListKeys.Add(PKEY_Device_Legacy, 'Legacy');
    ListKeys.Add(PKEY_Device_InstanceId, 'Instance Id');
    ListKeys.Add(PKEY_Device_ContainerId, 'Container Id');
    ListKeys.Add(PKEY_Device_ModelId, 'Model Id');
    ListKeys.Add(PKEY_Device_FriendlyNameAttributes, 'Friendly Name Attributes');
    ListKeys.Add(PKEY_Device_ManufacturerAttributes, 'Manufacturer Attributes');
    ListKeys.Add(PKEY_Device_PresenceNotForDevice, 'Presence Not For Device');
    ListKeys.Add(PKEY_Numa_Proximity_Domain, 'Numa Proximity Domain');
    ListKeys.Add(PKEY_Device_DHP_Rebalance_Policy, 'DHP Rebalance Policy');
    ListKeys.Add(PKEY_Device_Numa_Node, 'Numa Node');
    ListKeys.Add(PKEY_Device_BusReportedDeviceDesc, 'Bus Reported Device Desc');
    ListKeys.Add(PKEY_Device_InstallInProgress, 'Install In Progress');
{ Device driver properties }
    ListKeys.Add(PKEY_Device_DriverDate, 'Driver Date');
    ListKeys.Add(PKEY_Device_DriverVersion, 'Driver Version');
    ListKeys.Add(PKEY_Device_DriverDesc, 'Driver Desc');
    ListKeys.Add(PKEY_Device_DriverInfPath, 'Driver Inf Path');
    ListKeys.Add(PKEY_Device_DriverInfSection, 'Driver Inf Section');
    ListKeys.Add(PKEY_Device_DriverInfSectionExt, 'Driver Inf Section Ext');
    ListKeys.Add(PKEY_Device_MatchingDeviceId, 'Matching DeviceId');
    ListKeys.Add(PKEY_Device_DriverProvider, 'Driver Provider');
    ListKeys.Add(PKEY_Device_DriverPropPageProvider, 'Driver Prop Page Provider');
    ListKeys.Add(PKEY_Device_DriverCoInstallers, 'Driver CoInstallers');
    ListKeys.Add(PKEY_Device_ResourcePickerTags, 'Resource Picker Tags');
    ListKeys.Add(PKEY_Device_ResourcePickerExceptions, 'Resource Picker Exceptions');
    ListKeys.Add(PKEY_Device_DriverRank, 'Driver Rank');
    ListKeys.Add(PKEY_Device_DriverLogoLevel, 'Driver Logo Level');
    ListKeys.Add(PKEY_Device_NoConnectSound, 'No Connect Sound');
    ListKeys.Add(PKEY_Device_GenericDriverInstalled, 'Generic Driver Installed');
    ListKeys.Add(PKEY_Device_AdditionalSoftwareRequested, 'Additional Software Requested');
{Add more TPropertyKey here}

      //create a instance for the IFunctionDiscovery interface
      LFunctionDiscovery := CreateComObject(CLSID_FunctionDiscovery) as IFunctionDiscovery;
      try
        //set the provider
        pszCategory:=FCTN_CATEGORY_PNP;
        //get all the instances for the current provider
        hr := LFunctionDiscovery.GetInstanceCollection(pszCategory, nil, true, ppIFunctionInstanceCollection);
        if Succeeded(hr) then
          if Succeeded(ppIFunctionInstanceCollection.GetCount(pdwCount)) then
          begin
            if pdwCount=0 then
              Writeln(Format('No items was found for the %s category',[pszCategory]))
            else
            for i := 0 to pdwCount - 1 do begin
              if Succeeded(ppIFunctionInstanceCollection.Item(i, LFunctionInstance)) then
              begin
                //open the properties
                if Succeeded(LFunctionInstance.OpenPropertyStore(STGM_READ, ppIPropertyStore)) then
                begin
                   //get the num of properties for the current instance
                   ppIPropertyStore.GetCount(cProps);
                   for j := 0 to cProps - 1 do
                   begin
                      //get the TPropertyKey for the current index
                     if Succeeded(ppIPropertyStore.GetAt(j, pkey)) then
                      // get the value for the curent  TPropertyKey
                      if Succeeded(ppIPropertyStore.GetValue(pkey, pv)) then
                      begin
                       //resolves the key description or use the TGUID if is not found
                       KeyName:=pkey.fmtid.ToString;
                       if ListKeys.ContainsKey(pkey) then
                         KeyName:=ListKeys.Items[pkey];

                       //depending of the type of the property display the info
                       case pv.vt of
                         VT_BOOL    : Writeln(Format('%-40s %s',[KeyName , BoolToStr(pv.boolVal, True)]));
                         VT_UINT    : Writeln(Format('%-40s %d',[KeyName ,pv.ulVal]));
                         VT_INT     : Writeln(Format('%-40s %d',[KeyName ,pv.iVal]));
                         VT_I4,
                         VT_UI4     : Writeln(Format('%-40s %d',[KeyName ,pv.ulVal]));
                         VT_EMPTY   : Writeln(Format('%-40s %s',[KeyName ,'(Empty)']));
                         VT_LPWSTR  : Writeln(Format('%-40s %s',[KeyName ,pv.pwszVal]));
                         VT_CLSID   : Writeln(Format('%-40s %s',[KeyName ,pv.puuid^.ToString]));
                       else
                                    Writeln(Format('%-40s %s',[KeyName ,'(Type Unknow)']));
                       end;

                       PropVariantClear(pv);
                      end;
                   end;
                   Writeln;
                end;
              end
              else
               RaiseLastOSError;
            end;
          end
          else
           RaiseLastOSError
        else
         RaiseLastOSError;
      finally
        LFunctionDiscovery:=nil;
      end;
  finally
     ListKeys.Free;
  end;
end;


begin
 try
   if (Win32MajorVersion >= 6) then  // available on Vista (or later)
   begin
    if Succeeded(CoInitializeEx(nil, COINIT_MULTITHREADED)) then
    try
     Enumerate2;
    finally
      CoUninitialize;
    end;
   end
   else
   Writeln('Windows version not compatible');
 except
    on E:Exception do
        Writeln(E.Classname, ':', E.Message);
 end;
 Writeln('Press Enter to exit');
 Readln;
end.

This is just a basic sample of the use of the Function Discovery API, in the next post I will show another features of this API.

Author: Rodrigo

Just another Delphi guy.

4 thoughts on “Exploring Delphi XE3 – WinApi Additions – Winapi.Functiondiscovery Part 1

  1. Pingback: Exploring Delphi XE3 – WinApi Additions – Winapi.Functiondiscovery Part 2 « The Road to Delphi – a Blog about programming

  2. Pingback: Exploring Delphi XE3 – WinApi Additions – Winapi.Functiondiscovery Part 3 « The Road to Delphi – a Blog about programming

  3. Pingback: The Hacker’s Corner » Blog Archive » Record Helpers and Function Discovery

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