CDataPathProperty Class

Implements an OLE control property that can be loaded asynchronously.

Syntax

class CDataPathProperty : public CAsyncMonikerFile

Members

Public Constructors

Public Methods

Remarks

Asynchronous properties are loaded after synchronous initiation.

The class CDataPathProperty is derived from CAysncMonikerFile. To implement asynchronous properties in your OLE controls, derive a class from CDataPathProperty, and override OnDataAvailable.

For more information about how to use asynchronous monikers and ActiveX controls in Internet applications, see the following articles:

• Internet First Steps: ActiveX Controls

• Internet First Steps: Asynchronous Monikers

Inheritance Hierarchy

CObject

CFile

COleStreamFile

CMonikerFile

CAsyncMonikerFile

CDataPathProperty

Requirements

Header: afxctl.h

CDataPathProperty::CDataPathProperty

Constructs a CDataPathProperty object.

CDataPathProperty(COleControl* pControl = NULL);
CDataPathProperty(LPCTSTR lpszPath, COleControl* pControl = NULL);

Parameters

pControl
A pointer to the OLE control object to be associated with this CDataPathProperty 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. CDataPathProperty uses URLs, not filenames. If you want a CDataPathProperty 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.

CDataPathProperty::GetControl

Call this member function to retrieve the COleControl object associated with the CDataPathProperty object.

COleControl* GetControl();

Return Value

Returns a pointer to the OLE control associated with the CDataPathProperty object. NULL if not control is associated.

CDataPathProperty::GetPath

Call this member function to retrieve the path, set when the CDataPathProperty object was constructed, or specified in Open, or specified in a previous call to the SetPath member function.

CString GetPath() const;

Return Value

Returns the pathname to the property itself. Can be empty if no path has been specified.

CDataPathProperty::Open

Call this member function to initiate loading of the asynchronous property for the associated control.

virtual BOOL Open(
    COleControl* pControl,
    CFileException* pError = NULL);

virtual BOOL Open(
    LPCTSTR lpszPath,
    COleControl* pControl,
    CFileException* pError = NULL);

virtual BOOL Open(
    LPCTSTR lpszPath,
    CFileException* pError = NULL);

virtual BOOL Open(CFileException* pError = NULL);

Parameters

pControl
A pointer to the OLE control object to be associated with this CDataPathProperty object.

pError
A pointer to a file exception. In the event of an error, will be set to the cause.

lpszPath
The path, which may be absolute or relative, used to create an asynchronous moniker that references the actual absolute location of the property. CDataPathProperty uses URLs, not filenames. If you want a CDataPathProperty object for a file, prepend file:// to the path.

Return Value

Nonzero if successful; otherwise 0.

Remarks

The function attempts to obtain the IBindHost interface from the control.

Before calling Open without a path, the value for the property's path must be set. This can be done when the object is constructed, or by calling the SetPath member function.

Before calling Open without a control, an ActiveX control (formerly known as an OLE control) can be associated with the object. This can be done when the object is constructed, or by calling SetControl.

All overloads of CAsyncMonikerFile::Open are also available from CDataPathProperty.

CDataPathProperty::ResetData

Call this function to get CAsyncMonikerFile::OnDataAvailable to notify the container that the control properties have changed, and all the information loaded asynchronously is no longer useful.

virtual void ResetData();

Remarks

Opening should be restarted. Derived classes can override this function for different defaults.

CDataPathProperty::SetControl

Call this member function to associate an asynchronous OLE control with the CDataPathProperty object.

void SetControl(COleControl* pControl);

Parameters

pControl
A pointer to the asynchronous OLE control to be associated with the property.

CDataPathProperty::SetPath

Call this member function to set the pathname of the property.

void SetPath(LPCTSTR lpszPath);

Parameters

lpszPath
A path, which may be absolute or relative, to the property being loaded asynchronously. CDataPathProperty uses URLs, not filenames. If you want a CDataPathProperty object for a file, prepend file:// to the path.

See also

MFC Sample Image
CAsyncMonikerFile Class
Hierarchy Chart
CAsyncMonikerFile Class