4D Doc Center : CT Get refnum

4D Chart v12

CT Get refnum


CT Get refnum ( area ; scope ) -> Function result

Parameter	Type	Description
area	Longint	4D Chart area
scope	Longint	Scope of the function -2 = Default -1 = All 0 = Selected objects >0 = Object ID
Function result	Longint	Reference number for the objects in area

Description

CT Get refnum returns the reference number for the object(s) in the area described by scope. A reference number is a long integer associated with an object and is not necessarily unique. Reference numbers can only be manipulated programmatically. You assign a reference number to an object. The object ID, on the other hand, is assigned by 4D Chart.

If scope equals -2, CT Get refnum returns the default reference number.
If scope equals -1, CT Get refnum returns the reference number for all objects in the document. If the reference numbers for the objects are not equal, CT Get refnum returns -32000.
If scope equals 0, CT Get refnum returns the reference number for the selected objects. If the reference numbers for the objects are not equal, CT Get refnum returns -32000.
If scope is greater than 0, it must be equal to a specific object’s ID and that object’s reference number is returned. If the object does not exist, CT Get refnum returns -32000.

Example

This example is the object method for a button on a form that contains Area. When the method executes, it checks to see if only one object is selected, searches in the [Parts] table for the corresponding record, and displays its description

 QUERY([Parts];[Parts]RefNum=CT Get refnum(Area;0))

 ALERT("This object is a "+[Parts]Description)