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As any sharp-eyed reader may have
noticed, I have a rather sad interest in TCP/IP and its
use on the Pocket PC. When working with eVB, it is rather
like being interested in constantly banging your head on
the wall, but after a while, you forget about the pain,
and just get on with it. I got a bee in my bonnet about
writing a noughts and crosses (tic-tac-toe) game playable
between 2 Pocket PC's using IRDA or ethernet and eVB. During
the creation of the game, I used several of the articles
on devBuzz, so I thought it may make an interesting project,
drawing these areas together in a 'practical' project. A
game such as this cries out for a control array, but as
we know, these don't exist in eVB. This is where the article
Simulating
Control Arrays in eVB: http://www.devbuzz.com/content/zinc_evb_control_arrays_pg1.asp
came in useful.
Let's have a look at the screen design.
We have 2 frames, 1 for sorting out the connections and
1 for the game itself. We will take care of the positioning
in code. (See Building
a GUI Engine with Frames : http://www.devbuzz.com/content/zinc_evb_gui_frames_pg1.asp)
The 'connections' frame is pretty straightforward,
so we will look at the 'game frame' in more detail. The
rather fetching pink squares are in fact 9 picture box controls,
named xdisp0 to xdisp8.
This is where we will put our noughts and crosses. The names
will be explained in more detail shortly. We also add a
listbox, menubar, timer and of course a Winsock control.
The listbox will tell us what is happening, and the timer
will allow us to reset the game when we have a winner.
We will only show the more interesting
bits of the code, as the project is downloadable.
In our declarations we have:-
Private xdisp(8) As PictureBox
and in Form_Load
Set xdisp(0) = xdisp0
Set xdisp(1) = xdisp1
Set xdisp(2) = xdisp2
Set xdisp(3) = xdisp3
Set xdisp(4) = xdisp4
Set xdisp(5) = xdisp5
Set xdisp(6) = xdisp6
Set xdisp(7) = xdisp7
Set xdisp(8) = xdisp8
This allows us to simulate a control
array, as demonstrated in Robert
Levy's article.
The rest of the Form_Load procedure
is:-
MyScore = 0
opponentScore = 0
opponentName = "Opponent"
If IRDA Then
txtServer.Text = WinSock1.LocalHostName
Else
txtServer.Text = WinSock1.LocalIP
End If
Make_Menu
Frame1.Top = 0
Frame1.Left = 0
Frame1.Width = Me.Width
Frame1.Height = Me.Height
Frame1.ZOrder
IRDA = True
Simpsons = True
Choose_Picture
SoundOn = True
I decided it would be a good idea to
use sound in the game, and allow a choice of symbols. My
children are addicted to the Simpsons, so the decision was
taken out of my hands. To enable the game to be played silently
across the table in the board room or a meeting, the sound
is configurable, as is the ability to use IRDA or Ethernet.
This is where the menubar control comes in, and it is set
up in the Make_Menu Procedure.
We set Sound, IRDA and the Simpsons options here, so they
are checked when the game starts.
Private Sub Make_Menu()
Dim MenuItems
Set MenuItems = _&
MenuBar.Controls.AddMenu("Options")
MenuItems.Items.Add , 1, "Connect Screen"
MenuItems.Items.Add , 2, "Disconnect"
MenuItems.Items.Add , 3, "IRDA"
MenuItems.Items.Item(3).Checked = True
MenuItems.Items.Add , 4, "Sound"
MenuItems.Items.Item(4).Checked = True
MenuItems.Items.Add , 5, "Simpsons"
MenuItems.Items.Item(5).Checked = True
MenuItems.Items.Add , 6, "Exit"
End Sub
We start the game by showing the 'connections'
frame. Here we decide whether to be a server or to be a
client. If we are a server we will listen for a connection.
If we are a client, we must connect to a server. For ethernet,
we can use the IP address or name of the server, but for
IRDA, we MUST use the name. My 2 Pocket PC's are rather
imaginatively called Ipaq and Jornada. If we say that Ipaq
is the server, we would 'listen' on Ipaq by clickin on 'Be
a Server'. On Jornada, we would enter Ipaq in the textbox,
and click on 'Connect To'. This is where I found out that
names in IRDA are case-sensitive. 'Connect To' ipaq
would not find the server, where 'Connect To' Ipaq works.
The code for the 'listener' is handled
by the Winsock Connectionrequest event:-
Private Sub WinSock1_
ConnectionRequest()
On Error GoTo 0
opponentSymbol = "o"
MySymbol = "x"
myName = txtName.Text
WinSock1.Accept
bMyGo = True
WinSock1.SendData _
"OXNAME" & myName & "|"
lstStatus.AddItem _
"Connected to " & WinSock1.RemoteHostIP, 0
bReady = True
lstStatus.AddItem _
"Game Started. You are " & UCase(MySymbol)
_
& "'s", 0
lstStatus.AddItem "Your Go", 0
End Sub
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