# IPersistStreamInit

The IPersistStreamInit interface is defined as a replacement for IPersistStream in order to add an initialization method, InitNew. This interface is not derived from IPersistStream; it is mutually exclusive with IPersistStream. An object chooses to support only one of the two interfaces, based on whether it requires the InitNew method. Otherwise, the signatures and semantics of the other methods are the same as the corresponding methods of IPersistStream, except as described below.

##### When to Implement

Implement this interface on any object that needs to support initialized stream-based persistence, regardless of whatever else the object does. The presence of the InitNew method requires some changes to other methods that are common to IPersistStream, as noted in the method descriptions.

##### When to Use

Use this interface to initialize a stream-based object and to save that object to a stream.

Methods in Vtable Order

IUnknown Methods | Description
QueryInterface | Returns pointers to supported interfaces.
AddRef | Increments reference count.
Release | Decrements reference count.

IPersistStreamInit Methods | Description
IsDirty | Checks the object for changes since it was last saved.
Load | Initializes an object from the stream where it was previously saved.
Save | Saves an object into the specified stream and indicates whether the object should reset its dirty flag.
GetSizeMax | Return the size in bytes of the stream needed to save the object.
InitNew | Initializes an object to a default state.

See Also

IPersistStream