The information in this article applies to:
- Microsoft Visual FoxPro for Windows, version 3.0
SUMMARY
This article provides a method that illustrates how to build an outline
control and indent the elements in it without using the Indent property.
The example code builds a list of program names displayed by extension.
MORE INFORMATION
The sample program included in this article uses two tables and an array.
The first table (MSCodeType) stores file categories (extensions) such as
.prg, .exe, or .app. The second table (MSCodeExamples) lists file names by
category. The array has two dimensions; it records the program categories
and the number of items with this category.
The Technique Used by the Code Sample
The code sample uses the following technique.
- Build a list of types. The code first builds the list of files from the
MSCodeType table. It scans the MSCodeType table and places the elements
in the outline control and in the laNumAdded array.
- Add an item. To add an item to the list, the code uses the AddItem
method. Only one parameter, the string to add to the list, is passed to
the Additem method. Because no index number is specified, the new item
is added as a subordinate item, at the end of the list of subordinates
for the element selected. The ListIndex property is called to select an
item in the list before inserting a new item.
- Select an item in the list. The sample code scans the MSCodeExamples
table. It locates the program type in the array and increments the
number of programs with this type. It also selects the parent of the
item to insert. The ListIndex property is not absolute for an element;
it varies as elements are inserted into the list, so it is necessary to
calculate the position of the item in the list each time an element is
added. The code loops from the current element in the array to the first
element in the array, summing the number of files to estimate the
position of the current element to select. The number of file categories
(the parent in the outline control) is then summed to calculate the list
position of the current element. For example, if you want to add a .prg
type file name in the outline control, PRG is stored in the third row
in the array, so the array appears as follows:
Row Program_type Number_of_Files
-----------------------------------
1 EXE 2
2 HLP 3
3 PRG 4
The Outline looks like this:
EXE
Exe1
Exe2
Exe3
HLP
Hlp1
Hlp2
Hlp3
PRG
Prg1
Prg2
Prg3
The item to select is the PRG category type. The ListIndex of the item
to select is:
3+ 2 = 5 (go through the array in descending order, and calculate the
number of files above).
5+ 3-1 = 7 (adds the number of categories).
Code Sample
Follow the step-by-step procedure to run this program
- Create the data. Copy and paste the following code in a program to
create a database and two tables.
CLOSE ALL
CREATE DATABASE mscodedbc
CREATE TABLE MSCODETYPE (code_description C(3)) && Adds table to mydbc1
INSERT INTO mscodetype values ('PRG')
INSERT INTO mscodetype values ('HLP')
INSERT INTO mscodetype values ('APP')
CREATE TABLE MSCodeExamples (program_type C(3), Program_name M)
INSERT INTO mscodeExamples VALUES ('PRG', 'prgProgram1')
INSERT INTO mscodeExamples VALUES ('APP', 'appTest1')
INSERT INTO mscodeExamples VALUES ('HLP','hlpHelp1')
INSERT INTO msCodeExamples VALUES ('PRG', 'prgProgram2')
INSERT INTO msCodeExamples VALUES ('HLP','hlpHelp2')
- Create a form.
- Open the data environment of the form, and add the MSCodeType and the
MSCodeexamples tables to the Data Environment.
- Select the OleContainer from the Form Controls toolbar. Click Select
control, then click Outline Control. An outline control is placed on the
form.
- Copy the following code and paste it into the Init event of the outline
control.
SELECT MSCodeType
DIMENSION laNumAdded(RECCOUNT(),2)
SCAN
* Build the code types- the first indent of the outline
This.AddItem(MSCodeType.Code_Description)
laNumAdded(RECNO(),1) = 0
laNumAdded(RECNO(),2) = MSCodeType.Code_Description
ENDSCAN
* The table that contains file names
SELECT MSCodeExamples
SCAN
nIsTypeInArray=ASCAN(lanumadded,MSCodeExamples.Program_type)
nRow=ASUBSCRIPT(lanumadded,nIsTypeInArray,1)
* Find the position of the category in the array
laNumAdded(nRow,1) =laNumAdded(nrow,1) + 1
This.ListIndex = 0 && No item selected
* Loop through the array
FOR I = nrow-1 TO 1 STEP - 1
IF MSCodeExamples.Program_Type=lanumadded(1,2)
*aNumAdded(MSCodeExamples.Program_Type,2) = 0
This.ListIndex = 0
EXIT
ELSE
* Increment the index
This.ListIndex = This.ListIndex + laNumAdded(i,1)
ENDIF
ENDFOR
* Add the number of file categories to the ListIndex
This.ListIndex = This.ListIndex +nrow-1
lcProgram_Name = MLINE(MSCodeExamples.Program_Name,1)
* Add the item to the outline. It is added to the end of the subitems of
* the item currently selected.
This.AddItem(lcProgram_Name)
This.PictureType(This.ListIndex + ;
laNumAdded(MSCodeExamples.Program_Type,1)) = 2
ENDSCAN
This.ListIndex = 0
This.Parent.ReFresh
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