/// <summary>
/// Retrieves a list of available ELS platform-supported services, along with associated
/// information, according to application-specified criteria.
/// </summary>
/// <param name="options">Optional. A <see cref="MappingEnumOptions">MappingEnumOptions</see> object containing criteria to use during
/// enumeration of services. The application specifies null for this parameter to retrieve all
/// installed services.</param>
/// <returns>An array of <see cref="MappingService">MappingService</see> objects matching the criteria supplied in the options
/// parameter.</returns>
public static MappingService[] GetServices(MappingEnumOptions options)
{
ThrowIfNotWin7();
IntPtr servicePointer = IntPtr.Zero;
UInt32 serviceCount = 0;
UInt32 hresult = 0;
IntPtr guidPointer = IntPtr.Zero;
try
{
if (options != null)
{
Win32EnumOptions enumOptions = options._win32EnumOption;
Nullable <Guid> pGuid = options._guid;
if (pGuid != null)
{
Guid guid = (Guid)pGuid;
guidPointer = Marshal.AllocHGlobal(InteropTools.SizeOfGuid);
Marshal.StructureToPtr(guid, guidPointer, false);
enumOptions._pGuid = guidPointer;
}
hresult = Win32NativeMethods.MappingGetServices(ref enumOptions, ref servicePointer, ref serviceCount);
}
else
{
hresult = Win32NativeMethods.MappingGetServices(IntPtr.Zero, ref servicePointer, ref serviceCount);
}
if (hresult != 0)
{
throw new LinguisticException(hresult);
}
if ((servicePointer == IntPtr.Zero) != (serviceCount == 0))
{
throw new InvalidOperationException();
}
IntPtr[] services = new IntPtr[serviceCount];
ServiceCache.Instance.RegisterServices(ref servicePointer, services);
MappingService[] result = new MappingService[serviceCount];
for (int i = 0; i < serviceCount; ++i)
{
result[i] = new MappingService(services[i]);
}
return(result);
}
finally
{
if (servicePointer != IntPtr.Zero)
{
// Ignore the result if an exception is being thrown.
Win32NativeMethods.MappingFreeServicesVoid(servicePointer);
}
if (guidPointer != IntPtr.Zero)
{
Marshal.FreeHGlobal(guidPointer);
}
}
}
/// <summary>
/// Constructs a new <see cref="MappingService">MappingService</see> object by instanciating an ELS service
/// by its guid. For Windows 7, the only supported GUIDs are provided as
/// readonly members of the <see cref="MappingAvailableServices">MappingAvailableServices</see> class.
///
/// If the service
/// with the specified guid doesn't exist, a <see cref="LinguisticException">LinguisticException</see> is thrown.
/// </summary>
/// <param name="serviceIdentifier">The guid of the service to instantiate.</param>
public MappingService(Guid serviceIdentifier)
{
ThrowIfNotWin7();
IntPtr servicePointer;
UInt32 serviceCount = 0;
UInt32 hresult = 0;
// First, check to see if we already have the service in the cache:
servicePointer = ServiceCache.Instance.GetCachedService(ref serviceIdentifier);
if (servicePointer != IntPtr.Zero)
{
_service = servicePointer;
_win32Service = InteropTools.Unpack <Win32Service>(_service);
}
else // pService is IntPtr.Zero in this case.
{
// If we don't, we must find it via MappingGetServices:
IntPtr guidPtr = IntPtr.Zero;
try
{
guidPtr = Marshal.AllocHGlobal(InteropTools.SizeOfGuid);
Win32EnumOptions enumOptions = new Win32EnumOptions();
enumOptions._size = InteropTools.SizeOfWin32EnumOptions;
Marshal.StructureToPtr(serviceIdentifier, guidPtr, false);
enumOptions._pGuid = guidPtr;
hresult = Win32NativeMethods.MappingGetServices(ref enumOptions, ref servicePointer, ref serviceCount);
if (hresult != 0)
{
throw new LinguisticException(hresult);
}
if (servicePointer == IntPtr.Zero)
{
throw new InvalidOperationException();
}
if (serviceCount != 1)
{
hresult = Win32NativeMethods.MappingFreeServices(servicePointer);
if (hresult == 0)
{
throw new InvalidOperationException();
}
else
{
throw new LinguisticException(hresult);
}
}
IntPtr[] services = new IntPtr[1];
ServiceCache.Instance.RegisterServices(ref servicePointer, services);
_service = services[0];
_win32Service = InteropTools.Unpack <Win32Service>(_service);
}
finally
{
if (servicePointer != IntPtr.Zero)
{
// Ignore the result if an exception is being thrown.
Win32NativeMethods.MappingFreeServicesVoid(servicePointer);
}
if (guidPtr != IntPtr.Zero)
{
Marshal.FreeHGlobal(guidPtr);
}
}
}
}