PRB: SET INDEX TO Command Causes Error When Run from a Form

ID: Q140565

3.00 3.00b WINDOWS

The information in this article applies to:

• Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b

SYMPTOMS

One of the following errors occurs occur when attempting to run the SET INDEX TO command programmatically from a running form:

• File must be opened exclusively.

  -or-

• File is in use by another.

CAUSE

A table opened by the Data Environment of a form is opened shared by default. Therefore, when the form is running and you issue an INDEX ON command, an error occurs.

RESOLUTION

Set the Exclusive Property of the cursor to .T. at design time.

NOTE: Attempting to set this property at run-time causes the following error message:

   Property setting will not take effect until data environment reloaded

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a form.

2. Right-click the form, and then click Data Environment.

3. Right-click the Data Environment window, and then click Add.

4. Locate the Customer table in the Vfp\Samples\Data directory, and then select and add it to the Data Environment of the form.

5. Scroll down in the list box displaying the Customer table and note which indexes which currently exist. This is so that an index that already exists isn't recreated when the INDEX ON command is run in Step 7 later.

6. Add a command button to the form.

7. Add the following code to the Click method of the command button

     SELECT CUSTOMER
     INDEX ON <field_name> TAG <field_name>

   where field_name is the name of a field in the Customer table that does
   not already have an index tag, as noted earlier in Step 5.

9. Click the command button.

Steps to Correct Form Created in Previous Example

1. Close, and then edit the form.

2. Right-click the form, and then click Data Environment.

3. Right-click the Customer table list box, and then click Properties.

4. In the Properties window, click the Data tab, and then examine the

   Exclusive property. Note that the default value is .F.

Additional reference words: 3.00 3.00b VFoxWin KBCategory: KBSubcategory: FxtoolFormdes

Keywords          : kberrmsg FxtoolFormdes 
Version           : 3.00 3.00b
Platform          : WINDOWS