C# in a Nutshell, Second Edition

Name

IDisposable

Synopsis

This interface provides a last-ditch cleanup hook with well-known timing semantics (similar in concept to a C++ destructor). This is called deterministic finalization.

As part of normal garbage-collection operation, the CLR looks for (and calls if available) the object’s Finalize method right before it removes an object from heap memory. Unfortunately, because the CLR may not garbage-collect the object as soon as it becomes available for collection, objects may hold onto resources for longer than necessary. The IDisposable interface is intended to work with language constructs to let you ensure that key resources are released in a time-efficient manner.

Any object whose type implements the IDisposable interface must have a corresponding Dispose( ) method defined for it. This in turn makes the object eligible for use in the C# using block declaration. For more details, see “Using Statement” in Chapter 2.

If a type provides a Finalize method, then it should also inherit this interface and provide a corresponding Dispose( ) method. In addition, once the Dispose( ) method is called, part of its implementation should be to call the GC.SuppressFinalize( ) method to prevent the garbage collector from finalizing this object again when garbage collection occurs.

public interface IDisposable {
// Public Instance Methods
   public void Dispose( );
}

Implemented By

Multiple types