why cannot display message in form?[vb.net]

[kenny_oh]

the code pls refer here . i hv spend two week try to solve this problem but stil cannot solve the problem............the main problem is when the message receive want to display on the form, but the form appear and hanging halfway.......pls help solve the problem, my home work deadline is at the end of this week....pls

[Andy_P]

Firstly, this should probably be posted in the VB.NET forum, but try this:

Put this code in your 'Form A'

Private _strMessage As String
 
Public Sub New(ByVal msg As String)
 
Me.New() 'Calls the original New sub that has InitializeComponent
 
_strMessage = msg
 
txtMessageList.Text = _strMessage & vbCrLf
 
End Sub

Create your new 'Form A' like this

Private Sub loadMessage(ByVal message As System.String) Handles client1.displayMessage
 
Dim frmMessage As New FrmInstantMessage(message)
frmMessage.Show()
 
 End Sub

I hope that helps you out.

[kenny_oh]

problem stil exits........do u mind i send my application to u?

[Andy_P]

Yes, ok. PM you my email

[kenny_oh]

i didnt receive ur message..send to this [email protected]

[Andy_P]

Well I am not sure because I can't run the app properly because I can't do the net, and sockets stuff. Because I have VB.NET Standard maybe?

But, if I bypass the part of the app that involves this and just give a fixed string to the ReceiveMessage() method, it appears that it works. The InstantMessage form opens and contains the message that I supplied to it:

Public Sub ReceiveMessage()
 
    'client.GetStream.BeginRead(rBuffer, 0, rBufferSize, AddressOf read, Nothing)
    Dim message As String = "abc"
    RaiseEvent displayMessage(message)
 
End Sub

I would suggest thet you fade the opening of this form a bit quicker because it takes longer than one second, which is the time you have set in the main form timer. It might be causing a problem?

So, it apears to me that the problem may lie in the part of the app dealing with connection etc to the net, and sockets etc. Afraid I can't help you with any of that.

[kenny_oh]

hmmm....i try to do some change on what u said.......did u run the server application? u run the server application first.......then run the client application...if not i appear the messagebox said that cannot work without socket........

[kenny_oh]

i hv increase the timer interval but the same problem exist......can u run again my system.....i hv send another copy to u........u try to run the server application first bcoz client application connect to server.......in the server app got one button is use to send message to client to test whether it can receive the message or not......pls .....the biggest problem is on the form display there....!!

[kenny_oh]

Andy_p did u receive my application? the application can run?

[Andy_P]

Kenny, I cannot use the files included with the Server app. Are they VB6 project files or something? I have VB.NET only.

I can only think there is a problem the the GetStream.BeginRead or GetStream.EndRead methods, and I don't know anything about that I am afraid.

In the 'read' sub, you have two Msgbox's showing 'ByteRead' and 'message'. Do these appear and show what you expect to see?

If they do, remove them and don't interrupt the flow of the sub to see if that makes any difference.

That is the best i can suggest. Good luck!

[kenny_oh]

the server aplication is vb6 project.........

[kenny_oh]

i hv put two msgbox after the frmmessage.show and frmmessage.txtmessagelist.text = message & vbcrlf. this make the form display success but the mouse cursor show that the form stil loading something and never stop..........i realize that two msgbox like push the two lines code execute, if not there will not execute complete...what is ur comment on this?

[Andy_P]

My guess is that the BeginRead and EndRead is not completing correctly perhaps.

Try this code to allow only one read, to see if it is multiple calls to the read sub that is causing the problem.

Public Sub ReceiveMessage()
 
        Static onceOnly As Boolean
 
        If Not onceOnly Then
 
            onceOnly = True
            client.GetStream.BeginRead(rBuffer, 0, rBufferSize, AddressOf read, Nothing)
        
        End If
 
End Sub

[kenny_oh]

all the change u suggest, i hve done.....but the problem stil exist............really couldnt found the problem?

[Andy_P]

OK Kenny, I will give it one more shot...

Put the 'ReceiveMessage()' sub back to how it was.

Add this to the top of the main form:

Private f As FrmInstantMessage

Change the 'loadmessage' to this:

Private Sub loadMessage(ByVal IncomingMessage As String) Handles client.displayMessage
 
    If f Is Nothing Then
        f = New FrmInstantMessage(IncomingMessage)
    Else
        f.txtMessageList.Text = IncomingMessage
    End If
 
    f.Show()
 
End Sub

Try that, and see what happens.

[kenny_oh]

the new of frminstantmessage got argument?

[Andy_P]

Yes, if you still have the New(ByVal mg as String) sub entered.

Alternatively, you can do this if you prefer, which almost as you had it originally:

Private Sub loadMessage(ByVal IncomingMessage As String) Handles client.displayMessage
 
    If f Is Nothing Then
        f = New FrmInstantMessage
        f.txtMessageList.Text = IncomingMessage
    Else
        f.txtMessageList.Text = IncomingMessage
    End If
 
    f.Show()
 
End Sub

[kenny_oh]

hmmm....stil same problem.......last night u said that my beginRead and endRead got problem, what is the problem? it should not have probem since the message value can pass to loadmessage()

[kenny_oh]

Private Sub FrmInstantMessage_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
 
        TabControl1.SelectedIndex = 0
        btnSend.Enabled = False
 
        Me.Opacity = 0
        Me.timer = New Timer
        Me.timer.Interval = 50
        AddHandler timer.Tick, AddressOf formAppear
 
        Me.timer.Start()
 
End Sub

in the form_load event for frminstantmessage, is it any thing that is possible to cause the problem?

[kenny_oh]

this is my code for server application using vb6. the command button 1, i was uses to test the client side whether it receive the message....everything i press this button to test the receivemessage() for client

Option Explicit
 
Private ClientConnect
 
Private Sub Command1_Click()
    Winsock(ClientConnect).SendData (txtIncomingConnection.Text)
End Sub
 
Private Sub Form_Load()
    ClientConnect = 0
    Winsock(0).LocalPort = 8080
    Winsock(0).Listen
    txtIncomingConnection.Text = "Waiting Connection........"
End Sub
 
Private Sub Winsock_ConnectionRequest(index As Integer, ByVal requestID As Long)
    
    ClientConnect = ClientConnect + 1
 
    Load Winsock(ClientConnect)
    Winsock(ClientConnect).Close
    Winsock(ClientConnect).Accept requestID
    
    txtIncomingConnection.Text = "Connected"
    List1.AddItem (Winsock(ClientConnect).RemoteHostIP & vbTab & requestID & vbCrLf)
  
End Sub
 
Private Sub Winsock_DataArrival(index As Integer, ByVal bytesTotal As Long)
    
    Dim incomingdata As String
    
    Winsock(index).GetData incomingdata
    MsgBox bytesTotal
    Winsock(index).SendData (incomingdata & Winsock(index).LocalIP)
    txtIncomingConnection.Text = Now & ":" & "  " & incomingdata & vbNewLine
 
End Sub
 
Private Sub Winsock_SendComplete(index As Integer)
    MsgBox "Complete"
End Sub

[Andy_P]

This is what I said

My guess is that the BeginRead and EndRead is not completing correctly perhaps

I don't know what is wrong. I can't give you any help with the Network stream stuff because I don't know anything about it. I would suggest that having tried the things with the form, and making things run only once, and the problem still appears, then it is my guess that the problem does lie with the network stream code. BUT, I do not know for sure.

I really don't know what else to suggest, sorry.

[kenny_oh]

i hv a idea that change the read method to function to return value but the receivemessage() method addressof read cause some problem where procedure doesnt not match with function

Public Sub ReceiveMessage()
            client.GetStream.BeginRead(rBuffer, 0, rBufferSize, AddressOf read, Nothing)
End Sub
 
Public Sub read(ByVal dataIn As IAsyncResult)
 
 
        Dim ByteRead As Integer
        Dim message As String
 
        Try
 
            ByteRead = client.GetStream.EndRead(dataIn)
 
            If ByteRead < 1 Then
                Exit Sub
            End If
 
            message = Encoding.ASCII.GetString(rBuffer, 0, ByteRead)
 
            getMessage = True
 
            If getMessage = True Then
                RaiseEvent displayMessage(message)
            End If
 
        Catch
        End Try
 
    End Sub