CCachedDataPathProperty Class
Implements an OLE control property transferred asynchronously and cached in a memory file.
Syntax
class CCachedDataPathProperty : public CDataPathProperty
Members
Public Constructors
Name | Description |
---|---|
CCachedDataPathProperty::CCachedDataPathProperty | Constructs a CCachedDataPathProperty object. |
Public Data Members
Name | Description |
---|---|
CCachedDataPathProperty::m_Cache | CMemFile object in which to cache data. |
Remarks
A memory file is stored in RAM rather than on disk and is useful for fast temporary transfers.
Along with CAysncMonikerFile
and CDataPathProperty
, CCachedDataPathProperty
provides functionality for the use of asynchronous monikers in OLE controls. With CCachedDataPathProperty
objects, you are able to transfer data asynchronously from a URL or file source and store it in a memory file via the m_Cache
public variable. All the data is stored in the memory file, and there is no need to override OnDataAvailable unless you want to watch for notifications and respond. For example, if you are transferring a large .GIF file and want to notify your control that more data has arrived and it should redraw itself, override OnDataAvailable
to make the notification.
The class CCachedDataPathProperty
is derived from CDataPathProperty
.
For more information about how to use asynchronous monikers and ActiveX controls in Internet applications, see the following topics:
Inheritance Hierarchy
CCachedDataPathProperty
Requirements
Header: afxctl.h
CCachedDataPathProperty::CCachedDataPathProperty
Constructs a CCachedDataPathProperty
object.
CCachedDataPathProperty(COleControl* pControl = NULL);
CCachedDataPathProperty(
LPCTSTR lpszPath,
COleControl* pControl = NULL);
Parameters
pControl
A pointer to the ActiveX control object to be associated with this CCachedDataPathProperty
object.
lpszPath
The path, which may be absolute or relative, used to create an asynchronous moniker that references the actual absolute location of the property. CCachedDataPathProperty
uses URLs, not filenames. If you want a CCachedDataPathProperty
object for a file, prepend file:// to the path.
Remarks
The COleControl
object pointed to by pControl is used by Open and retrieved by derived classes. If pControl is NULL, the control used with Open
should be set with SetControl. If lpszPath is NULL, you can pass in the path through Open
or set it with SetPath.
CCachedDataPathProperty::m_Cache
Contains the class name of the memory file into which data is cached.
CMemFile m_Cache;
Remarks
A memory file is stored in RAM rather than on disk.
See also
CDataPathProperty Class
Hierarchy Chart
CDataPathProperty Class