You can use the AEVENTS( ) function to retrieve the number of existing event bindings.

AEVENTS( ArrayName [, 0 | 1 | oEventObject ] )

Parameters

ArrayName

Specifies the name of the array that contains the results of AEVENTS( ).

0

Specifies that AEVENTS( ) returns a three-element array containing an object reference to the current event source, the name of the triggered event, and how the event was triggered.

Column	Description	Type
1	Event source	Object reference
2	Event	String
3	Event type, or how event was raised.	0 - System 1 - RAISEEVENT( ) function 2 - Method call

The third array element indicates how an event was triggered. If the event is a property, this value can be 1 or 2. The value is 2 if the property is set or assigned.

1

Specifies that AEVENTS( ) returns a four-column array containing information about Windows Message (Win Msg) events.

The array contains one row for each binding. Bindings are created with the BINDEVENT( ) Function.

The following table describes the contents of each column in the array.

Column	Description	Type
1	hWnd	Integer
2	Window Message	Integer
3	Reference of handler	Object reference
4	Handler delegate	String

oEventObject

Specifies an object reference. If you specify an object reference, AEVENTS( ) returns a five-column array that contains the events raised and the delegate methods for oEventObject. Each row in ArrayName represents a binding. The following table describes the information in each of the five columns.

Column	Description	Type
1	.T. if second element is the event source .F. if second element is the event handler	Logical
2	Event source if you pass the event handler to oEventObject; otherwise, event handler if you pass the event source to oEventObject.	Object reference
3	Event	String
4	Delegate method	String
5	BINDEVENT( ) flags	Integer

When you pass oEventObject, the number of bindings returned by AEVENTS( ) should equal the number of unbound events returned by the UNBINDEVENTS( ) function when passing only the oEventObject parameter.

Return Value

Remarks

Example

The following example shows how to use AEVENTS( ) to retrieve the number of existing event bindings. BINDEVENTS( ) keeps the Class Browser positioned to the right side of the Visual FoxPro desktop, regardless of how the desktop is resized. For more information, see BINDEVENT( ) Function.

UNBINDEVENTS( ) detaches the Resize event of the _SCREEN system variable from the object, oHandler. AEVENTS( ) returns the number of event bindings before BINDEVENT( ) and after UNBINDEVENTS( ) in an array called myArray:

Copy Code

PUBLIC oHandler oHandler=NEWOBJECT("myhandler") DO (_browser) BINDEVENT(_SCREEN,"Resize",oHandler,"myresize") AEVENTS(myArray,oHandler) numRows=ALEN(myArray,1) numCols=ALEN(myArray,2) WAIT "Rows in array after binding: " + TRANSFORM(numRows) WINDOW AT 20,20 WAIT "Cols in array after binding: " + TRANSFORM(numCols) WINDOW AT 20,20 FOR count1 = 1 TO numRows FOR count2 = 1 TO numCols WAIT myArray[count1,count2] WINDOW AT 20,20 ENDFOR ENDFOR * Comment the following line to see event binding persist. UNBINDEVENTS(_SCREEN,"Resize",oHandler,"myresize") AEVENTS(myArray,oHandler) * Check if AEVENTS( ) created and populated new array. IF VARTYPE(myArray) <> U * The following code does not execute if event is unbound because * AEVENT( ) does not create a new array if it returns 0. To execute * the following code and see the contents of the new array, uncomment * the UNBINDEVENTS( ) statement. numRows=ALEN(myArray,1) numCols=ALEN(myArray,2) WAIT "Rows in array after unbinding: " + TRANSFORM(numRows) ; WINDOW AT 20,20 WAIT "Cols in array after unbinding: " + TRANSFORM(numCols) ; WINDOW AT 20,20 FOR count1 = 1 TO numRows FOR count2 = 1 TO numCols WAIT myArray[count1,count2] WINDOW AT 20,20 ENDFOR ENDFOR ENDIF DEFINE CLASS myhandler AS Session PROCEDURE myresize _obrowser.left = _SCREEN.Width - _obrowser.width RETURN ENDDEFINE

See Also