PRB: "Expand is not an array" Error When Using Outline Control

• Microsoft Visual FoxPro for Windows, version 3.0

SYMPTOMS

The Outline control has an Expand property and an Expand event. According to Visual FoxPro Help, you can expand an item of an Outline control (Outline1) by using this code:

   THISFORM.Outline1.Expand(<Item#>) = .T.

   'Expand' is not an array

CAUSE

Visual FoxPro is interpreting Expand as a property of the Outline container object. The syntax is similar to referencing Expand as an array. That is why Visual FoxPro reports this error. You need to tell Visual FoxPro that this is a property of the OLE control that the container is holding. The Help documentation is incomplete.

RESOLUTION

The Object property provides access to the OLE server properties and methods for an OLE object. Therefore, to expand an item, you can use this code:

   THISFORM.Outline1.Object.Expand(<Item#>) = .T.

STATUS

This behavior is by design.

MORE INFORMATION

The Outline control (Msoutl32.ocx) is a special type of list box that you can use to display items in a list hierarchically. This is useful for showing directories and files in a file system; it is the technique used by the Windows File Manager.

Steps to Reproduce Behavior

1. Open the Debug window, and enter this line:

   _SCREEN.ACTIVEFORM.ACTIVECONTROL.ListIndex

2. Use the DO FORM command to run the Outline1.scx form in the Samples\Ole directory.

3. Click the Select a Database button, and select the Testdata.dbc (from the Samples\Data directory)

4. Click different lines on the Outline Sample form to see that the ListIndex changes. Make sure the Customer line (ListIndex 0) is selected but not expanded (collapsed) before you perform the next step.

5. To expand the Customer item programmatically, type the following command in the Command window:

   _SCREEN.ACTIVEFORM.OLEControl1.Expand(0) = .T.

   This will return the error noted above: "'Expand' is not an array."

6. To get the correct behavior, use the following line of code instead:

   _SCREEN.ACTIVEFORM.OLEControl1.Object.Expand(0) = .T.