populating listbox

[thegame8311]

greetings

I can seem to populate my listbox. When I run my code nothing is showing in the listbox

here's what I have so far:

LPARAMETERS cItem

lp1.listbox1.RowSourceType = 3
lp1.listbox1.RowSource = "SELECT * FROM LivePlayers INTO CURSOR myCursor"

lp1.listbox1.value = myCursor.pid

I have values in my table, so what could I be missing?

 

[Dan Freeman]

When you change the contents of a listbox, you have to call the Listbox.Requery()

 

[Mike Lewis]

When you use Rowsourcetype = 3, the cursor (MyCursor in this case) is dummy cursor. The actual cursor that's used to populate the listbox is created behind the scenes.

So lp1.listbox1.value = myCursor.pid doesn't have any effect.

Either change the above line to lp1.listbox.ListIndex= 1. Or, better, do this:

SELECT * FROM LivePlayers INTO CURSOR myCursor
lp1.listbox1.RowSourceType = [b]2[/b]
lp1.listbox1.RowSource = "MyCursor"
lp1.listbox1.Listindex = 1

Also, if you want to see all the fields from LivePlayers, then you need to set the ColumnCount accordingly.

In fact, you could also do this:

lp1.listbox1.RowSourceType = [b]2[/b]
lp1.listbox1.RowSource = "LivePlayers"
lp1.listbox1.Listindex = 1

Mike



__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[thegame8311]

cool, well now that does not set any of the properties, but why, does it need to go into an event or somewhere else?

 

[Olaf Doschke]

Mike's code can replace your code at the position it is right now.

The ideal place to put initialisation code is the Init() event of course. Data retreival can also go into the OpenTables() method of the forms dataenvironment or into the Load() of the form, previous to any init of any control. However you like it.

Bye, Olaf.

 

[Mike Lewis]

My own choice would be to put the code in the Init of the listbox, as that would make it more self-contained. But it could also go in the Init of the form.

Mike


__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[Olaf Doschke]

A little bit beyond the scope of this question:

Yes Mike, that's good from the OOP encapsulation perspective, of course.

But I rather see it from the perspective of application layers. And while it's good an object to be self contained, responsible for it's own state including data binding, it makes this control object work throughout many application layers, as it's part of the GUI and will then drill down to the database, which is a no go with seperating the concerns of presentation and persisting data to seperate modules.

Actually you can combine both the OOP thought and the thought on decoupling aspects in the N tier application layer model, by letting a control not directly access data in it's init, but still let it call an object representing the next layer of the app to delegate fetching the data for it.

That way the control would take care of missing data on it's own anyway and the data access layer would only query data the control really needs to display.

I still prefer the push of data into the GUI and not an intelligent GUI requesting what it wants to display, because having the presentation centrelised gives more overview to the programmer for interdependencies and the business layer can more easy be adopted to a whole new form in one central databinding method, perhaps.

Bye, Olaf.

 

[thegame8311]

ok, that worked, but now I am adding values from one table to another, but when I try to use the following the listbox does not refresh or requery

thisform.list1.refresh
thisform.list1.requery

I have those in the add button so after it adds it to the table it should show me the updated list, but it is not

 

[Mike Lewis]

Just doing a requery isn't enough. You need to regenerate your cursor.

Try running the same code (the code that does the SELECT, etc.) from the button that's used to add the data to the table.

Mike

__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[thegame8311]

would it help to put that same select code into the requery function?

 

[Olaf Doschke]

Mike initially gave you 2 alternatives. Alternative 2 was just setting lp1.listbox1.RowSource = "LivePlayers" instead of a query into a cursor named "MyCursor".

If you do that the listbox requery() will show the new records.

Bye, Olaf.

 

[Mike Lewis]

Yes, Olaf is correct. TheGame, if you could post the actual code you are using, it might be easier to advise you.

Mike

__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[thegame8311]

it's ok I figured that part out.

The part that is getting me now is 'field' phrase is not found

Here is the code:

thisform.list1.RowSourceType = 2
thisform.list1.RowSource = "TestTeam"
thisform.list1.Listindex = 2 
thisform.list1.ColumnCount = 3
thisform.list1.ColumnWidths = "100,150,150"

it's pointing at my Rowsource line. the table exists, so I'm confused why I keep getting this error

 

[Olaf Doschke]

Sepcifying a table not yet opened is not possible, unlike SQL-SELECT From opening a table a rowsource, even in rowsourcetype 2 can not only be a table name, but an expression with table and field names and thus vfp just errors this way instead of opening TestTeam.dbf

Bye, Olaf.

 

[Mike Lewis]

Yes, I agree with Olaf. Make sure that TestTeam is open before you run that code. If that doesn't solve the problem, come back, and we can look at it in more detail.

Mike


__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[Olaf Doschke]

Just to clarify: With "can not only" I meant it's also possible the rowsource is an expression in general, it does not need to be a table or alias name, even if you specify rowsourcetype alias. So vfp does not know it should open that table, unlike with SQL-Select, where it actually does open not yet opened tables.

Bye, Olaf.

 

[thegame8311]

So if I insert a

Use "table"

before the rowsource code then it should work

 

[thegame8311]

Also I was wondering if you can do this:

thisform.list2.RowSourceType = 2
thisform.list2.RowSource = lnTeam
thisform.list2.Listindex = 2 
thisform.list2.ColumnCount = 3
thisform.list2.ColumnWidths = "100,150,150"

where lnTeam is a variable

 

[Mike Lewis]

Use "table"

No. Remove the double quotes. For example:

USE TestTeam

But you need to do that once only, before you call the code that sets the RowSource. For example, do it in the Load event of the form. (And you should only do it if the table is not already open.)

This is a better way:

IF NOT USED("TestTeam")
  USE TestTeam IN 0
ENDIF

thisform.list2.RowSource = lnTeam

What's lnTeam? Is it a variable that holds the name of the table? If so, that's fine.

The stuff with column count and column widths look OK too.

Mike


__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[thegame8311]

Yes lnTeam holds the table name