Miscellaneous Marshaling Samples

Factors such as garbage collection and threading can impact the behavior of the interop marshaler. Further, subtle differences in programming and type models can make passing data to an unmanaged library confusing. This section provides a set of samples that address some of these differences.

The following table lists marshaling options for various types of items, describes their usage, and provides a link to the corresponding sample.

Type of item	Description	Sample
Function pointer	Passes a delegate to an unmanaged function that expects a function pointer.	Callback
HandleRef	Uses the HandleRef structure to prevent garbage collection.	HandleRef
LPARAM	Uses the GCHandle structure to pass a managed object to an unmanaged function that expects an LPARAM type.	GCHandle
Single-threaded apartment (STA)/multithreaded apartment (MTA)	Changes the default apartment settings when an unmanaged function calls CoInitialize.	ActiveDir
void*	Calls a function that has void* as a parameter.	Void

See Also

Concepts

Platform Invoke Data Types

Marshaling Strings

Marshaling Classes, Structures, and Unions

Marshaling Arrays of Types

Other Resources

Marshaling Data with Platform Invoke