// Display property page for the specified object
private void DisplayPropertyPage( IntPtr parentWindow, object sourceObject )
{
try
{
// retrieve ISpecifyPropertyPages interface of the device
ISpecifyPropertyPages pPropPages = (ISpecifyPropertyPages) sourceObject;
// get property pages from the property bag
CAUUID caGUID;
pPropPages.GetPages( out caGUID );
// get filter info
FilterInfo filterInfo = new FilterInfo( deviceMoniker );
// create and display the OlePropertyFrame
Win32.OleCreatePropertyFrame( parentWindow, 0, 0, filterInfo.Name, 1, ref sourceObject, caGUID.cElems, caGUID.pElems, 0, 0, IntPtr.Zero );
// release COM objects
Marshal.FreeCoTaskMem( caGUID.pElems );
}
catch
{
}
}
// Collect filters of specified category
private void CollectFilters( Guid category )
{
object comObj = null;
ICreateDevEnum enumDev = null;
IEnumMoniker enumMon = null;
IMoniker[] devMon = new IMoniker[1];
int hr;
try
{
// Get the system device enumerator
Type srvType = Type.GetTypeFromCLSID( Clsid.SystemDeviceEnum );
if ( srvType == null )
throw new ApplicationException( "Failed creating device enumerator" );
// create device enumerator
comObj = Activator.CreateInstance( srvType );
enumDev = (ICreateDevEnum) comObj;
// Create an enumerator to find filters of specified category
hr = enumDev.CreateClassEnumerator( ref category, out enumMon, 0 );
if ( hr != 0 )
throw new ApplicationException( "No devices of the category" );
// Collect all filters
IntPtr n = IntPtr.Zero;
while ( true )
{
// Get next filter
hr = enumMon.Next( 1, devMon, n );
if ( ( hr != 0 ) || ( devMon[0] == null ) )
break;
// Add the filter
FilterInfo filter = new FilterInfo( devMon[0] );
InnerList.Add( filter );
// Release COM object
Marshal.ReleaseComObject( devMon[0] );
devMon[0] = null;
}
// Sort the collection
InnerList.Sort( );
}
catch
{
}
finally
{
// release all COM objects
enumDev = null;
if ( comObj != null )
{
Marshal.ReleaseComObject( comObj );
comObj = null;
}
if ( enumMon != null )
{
Marshal.ReleaseComObject( enumMon );
enumMon = null;
}
if ( devMon[0] != null )
{
Marshal.ReleaseComObject( devMon[0] );
devMon[0] = null;
}
}
}
