IPersistStorage::Load
A version of this page is also available for
4/8/2010
This method loads an object from its existing storage.
Syntax
HRESULT Load(
IStorage* pStg
);
Parameters
- pStg
[in] IStorage pointer to the existing storage from which the object is to be loaded.
Return Value
The following table shows the return values for this method.
| Value | Description |
|---|---|
S_OK |
The object was successfully loaded. |
CO_E_ALREADYINITIALIZED |
The object has already been initialized by a previous call to the IPersistStorage::Load method or the IPersistStorage::InitNew method. |
E_OUTOFMEMORY |
The object was not loaded due to lack of memory. |
E_FAIL |
The object was not loaded due to some reason besides a lack of memory. |
Remarks
This method initializes an object from an existing storage. The object is placed in the loaded state if this method is called by the container application. If called by the default handler, this method places the object in the running state.
Either the default handler or the object itself can hold onto the IStorage pointer while the object is loaded or running.
To determine whether the platform supports this interface, see Determining Supported COM APIs.
Notes to Callers
The container should cache the IPersistStorage pointer for use in later operations on the object.
Notes to Implementers
Your implementation should perform the following steps to load an object:
- Open the object's streams in the storage object, and read the necessary data into the object's internal data structures.
- Clear the object's dirty flag.
- Call the IPersistStorage::AddRef method and cache the passed in storage pointer.
- Keep open and cache the pointers to any streams or storages that the object will need to save itself to this storage.
- Perform any other default initialization required for the object.
Steps 3 and 4 are particularly important for ensuring that the object can save itself in low memory situations. Holding onto pointers to the storage and stream interfaces guarantees that a save operation to this storage will not fail due to insufficient memory.
Your implementation of this method should return the CO_E_ALREADYINITIALIZED error code if it receives a call to either the IPersistStorage::InitNew method or the IPersistStorage::Load method after it is already initialized.
Requirements
| Header | objidl.h, objidl.idl |
| Library | ole32.lib, uuid.lib |
| Windows Embedded CE | Windows CE 2.0 and later |
| Windows Mobile | Windows Mobile Version 5.0 and later |