Ex 2-1 TicTacToe

zavodney · May 23rd, 2011, 12:15 AM

I finished the first example and then added a button to clear all the large labels. This isn't working because of my 'clear' line. Any suggestions or will I learn all about this later?? It also didn't work without the extra " marks.

code
Private Sub btnNewGame_Click(sender As System.Object, e As System.EventArgs) Handles btnNewGame.Click
' clear all lblTaken
For x = 0 To 2
For y = 0 To 2
"lblTaken"xy".text" = ""
Next y
Next x

End Sub
/code

Rod Stephens · May 23rd, 2011, 09:02 AM

Unfortunately you can't use a string to name a control in this way.

Code:

"lblTaken"xy".text" = ""

There are several ways you can approach this. The easiest but least satisfying is to just clear them individually:

Code:

lblTaken00.Text = ""
lblTaken01.Text = ""
lblTaken02.Text = ""
...

Probably if you are going to turn this into a more realistic program, you would want to make an array holding the labels. Then you can loop through the array to clear them out. Arrays are described in Lesson 16, although I don't think that lesson revisits the Tic-Tac-Toe program.

The program would declare the array outside of any method:

Code:

Private Labels As Label(,)

When it starts, the program would initialize the array something like this:

Code:

Labels = New Label(,) _
{ _
    {lblTaken00, lblTaken01, lblTaken02}, _
    {lblTaken10, lblTaken11, lblTaken12}, _
    {lblTaken20, lblTaken21, lblTaken22} _
}

Later you can loop through the array like this:

Code:

For r As Integer = 0 To 2
    For c As Integer = 0 To 2
        Labels(r, c).Text = ""
    Next c
Next r

This is all getting pretty far ahead of the Tic-Tac-Toe program in Lesson 2 but perhaps later you can revisit this and see if you can make it work.

zavodney · May 23rd, 2011, 02:57 PM

OK, thank you. I can wait until later. Clearing each label individually was an option, but it wasn't a satisfying way to do it. Thank you.

Keith