/// <summary>
/// Gets or creates a COM object and returns the transparent proxy which intercepts all calls to the object
/// The ComProgId can be a normal ComProgId or a GUID prefixed with "clsid:"
/// </summary>
/// <typeparam name="T">Interface which defines the method and properties to intercept</typeparam>
/// <returns>Transparent proxy to the real proxy for the object</returns>
/// <remarks>T must be an interface decorated with the <see cref="ComProgIdAttribute" />attribute.</remarks>
public static T GetOrCreateInstance <T>()
{
var type = typeof(T);
if (null == type)
{
throw new ArgumentNullException(nameof(T));
}
if (!type.IsInterface)
{
throw new ArgumentException("The specified type must be an interface.", nameof(T));
}
var progIdAttribute = ComProgIdAttribute.GetAttribute(type);
if (string.IsNullOrEmpty(progIdAttribute?.Value))
{
throw new ArgumentException("The specified type must define a ComProgId attribute.", nameof(T));
}
object comObject = null;
Type comType = null;
var progId = progIdAttribute.Value;
var guid = Guid.Empty;
// Convert from clsid to Prog ID, if needed
if (progId.StartsWith("clsid:"))
{
guid = new Guid(progId.Substring(6));
var result = ProgIDFromCLSID(ref guid, out progId);
if (result != 0)
{
// Restore progId, as it's overwritten
progId = progIdAttribute.Value;
try
{
GetActiveObject(ref guid, IntPtr.Zero, out comObject);
}
catch (Exception)
{
Log.Warn().WriteLine("Error {0} getting instance for class id {1}", result, progIdAttribute.Value);
}
if (comObject == null)
{
Log.Warn().WriteLine("Error {0} getting progId {1}", result, progIdAttribute.Value);
}
}
else
{
Log.Info().WriteLine("Mapped {0} to progId {1}", progIdAttribute.Value, progId);
}
}
if (comObject == null && !progId.StartsWith("clsid:"))
{
try
{
comObject = Marshal.GetActiveObject(progId);
}
catch (COMException comE)
{
if (comE.ErrorCode == MK_E_UNAVAILABLE)
{
Log.Debug().WriteLine("No current instance of {0} object available.", progId);
}
else if (comE.ErrorCode == CO_E_CLASSSTRING)
{
Log.Warn().WriteLine("Unknown progId {0} (application not installed)", progId);
return(default(T));
}
else
{
Log.Warn().WriteLine(comE, "Error getting active object for " + progId);
}
}
catch (Exception e)
{
Log.Warn().WriteLine(e, "Error getting active object for " + progId);
}
}
// Did we get the current instance? If not, try to create a new
if (comObject == null)
{
try
{
comType = Type.GetTypeFromProgID(progId, true);
}
catch (Exception ex)
{
if (Guid.Empty != guid)
{
comType = Type.GetTypeFromCLSID(guid);
}
else
{
Log.Warn().WriteLine(ex, "Error type for " + progId);
}
}
if (comType != null)
{
try
{
comObject = Activator.CreateInstance(comType);
if (comObject != null)
{
Log.Debug().WriteLine("Created new instance of {0} object.", progId);
}
}
catch (Exception e)
{
Log.Warn().WriteLine(e, "Error creating object for " + progId);
}
}
}
if (comObject != null)
{
if (comObject is IDispatch)
{
var wrapper = new ComWrapper(comObject, type, progIdAttribute.Value);
return((T)wrapper.GetTransparentProxy());
}
return((T)comObject);
}
return(default(T));
}
/// <summary>
/// A simple create instance, doesn't create a wrapper!!
/// </summary>
/// <typeparam name="TCom">Type of the COM</typeparam>
/// <returns>T</returns>
public static TCom CreateInstance <TCom>()
{
var type = typeof(TCom);
if (null == type)
{
throw new ArgumentNullException(nameof(TCom));
}
if (!type.IsInterface)
{
throw new ArgumentException("The specified type must be an interface.", nameof(TCom));
}
var progIdAttribute = ComProgIdAttribute.GetAttribute(type);
if (string.IsNullOrEmpty(progIdAttribute?.Value))
{
throw new ArgumentException("The specified type must define a ComProgId attribute.", nameof(TCom));
}
var progId = progIdAttribute.Value;
Type comType = null;
if (progId.StartsWith("clsid:"))
{
var guid = new Guid(progId.Substring(6));
try
{
comType = Type.GetTypeFromCLSID(guid);
}
catch (Exception ex)
{
Log.Warn().WriteLine("Error {1} type for {0}", progId, ex.Message);
}
}
else
{
try
{
comType = Type.GetTypeFromProgID(progId, true);
}
catch (Exception ex)
{
Log.Warn().WriteLine("Error {1} type for {0}", progId, ex.Message);
}
}
object comObject = null;
if (comType != null)
{
try
{
comObject = Activator.CreateInstance(comType);
if (comObject != null)
{
Log.Debug().WriteLine("Created new instance of {0} object.", progId);
}
}
catch (Exception e)
{
Log.Warn().WriteLine("Error {1} creating object for {0}", progId, e.Message);
throw;
}
}
if (comObject != null)
{
return((TCom)comObject);
}
return(default(TCom));
}