Re: VB, sending messages to another app using SendMessage / PostMessage.

Tech-Archive recommends: Speed Up your PC by fixing your registry

Before I go into detail, there's a few things you could try:

Hopefully, you have the Spy++ tool in your VB installation. It's a very
useful tool to get information about windows and window messages.
If you have it, you can
a) check whether the hWnd you get is actually the hWnd of the edit field
b) Attach to that window's message queue, and look whether the messages you
send actually arrive.

Robert

<DarthContinent@xxxxxxxxx> wrote in message
news:1125982172.882901.168660@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Hello, could someone more fluent than I in VB please examine the
> following and help me understand where the problem may lie?
>
> Basically I begin by grabbing the handle to an "edit" control within
> the main program (a game, Jedi Academy), and try to input text into
> that control using SendMessage.
>
> However, no matter what I've tried so far I can't seem to get any
> reaction from the game, I get no feedback whatsoever indicating that
> the messages I'm expecting have been successfully received. I get a
> nonzero value in response to FindWindow / FindWindowEx, which I
> understand indicates that the handle was acquired successfully, so I'm
> pretty sure I'm grabbing the right handle, it's just not going from
> there.
>
> Could it be an issue with focus? Does the app I'm grabbing a handle to
> need to have the focus before it will accept and process messages in
> this way?
>
> Or are my function definitions somehow incorrect / incomplete?
>
> Any suggestions would be appreciated, I've scoured the newsgroups and
> I'm afraid I haven't been able to gather much to help me out of my own
> hole.
>
> ---
>
> <BEGIN CODE>
>
>
> Imports System.Runtime.InteropServices
> Public Class Form1
> Inherits System.Windows.Forms.Form
>
> #Region " Windows Form Designer generated code "
>
> Public Sub New()
> MyBase.New()
>
> 'This call is required by the Windows Form Designer.
> InitializeComponent()
>
> 'Add any initialization after the InitializeComponent() call
>
> End Sub
>
> 'Form overrides dispose to clean up the component list.
> Protected Overloads Overrides Sub Dispose(ByVal disposing As
> Boolean)
> If disposing Then
> If Not (components Is Nothing) Then
> components.Dispose()
> End If
> End If
> MyBase.Dispose(disposing)
> End Sub
>
> 'Required by the Windows Form Designer
> Private components As System.ComponentModel.IContainer
>
> 'NOTE: The following procedure is required by the Windows Form
> Designer
> 'It can be modified using the Windows Form Designer.
> 'Do not modify it using the code editor.
> Friend WithEvents Button1 As System.Windows.Forms.Button
> Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
> Friend WithEvents Label2 As System.Windows.Forms.Label
> Friend WithEvents Label3 As System.Windows.Forms.Label
> <System.Diagnostics.DebuggerStepThrough()> Private Sub
> InitializeComponent()
> Me.Button1 = New System.Windows.Forms.Button
> Me.TextBox1 = New System.Windows.Forms.TextBox
> Me.Label2 = New System.Windows.Forms.Label
> Me.Label3 = New System.Windows.Forms.Label
> Me.SuspendLayout()
> '
> 'Button1
> '
> Me.Button1.Location = New System.Drawing.Point(16, 48)
> Me.Button1.Name = "Button1"
> Me.Button1.Size = New System.Drawing.Size(264, 32)
> Me.Button1.TabIndex = 0
> Me.Button1.Text = "send string in textbox to other app"
> '
> 'TextBox1
> '
> Me.TextBox1.Location = New System.Drawing.Point(16, 16)
> Me.TextBox1.Name = "TextBox1"
> Me.TextBox1.Size = New System.Drawing.Size(264, 20)
> Me.TextBox1.TabIndex = 1
> Me.TextBox1.Text = "some sample text"
> '
> 'Label2
> '
> Me.Label2.Location = New System.Drawing.Point(16, 96)
> Me.Label2.Name = "Label2"
> Me.Label2.Size = New System.Drawing.Size(256, 24)
> Me.Label2.TabIndex = 3
> Me.Label2.Text = "Label2"
> '
> 'Label3
> '
> Me.Label3.Location = New System.Drawing.Point(16, 128)
> Me.Label3.Name = "Label3"
> Me.Label3.Size = New System.Drawing.Size(256, 24)
> Me.Label3.TabIndex = 4
> Me.Label3.Text = "Label3"
> '
> 'Form1
> '
> Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
> Me.ClientSize = New System.Drawing.Size(292, 165)
> Me.Controls.Add(Me.Label3)
> Me.Controls.Add(Me.Label2)
> Me.Controls.Add(Me.TextBox1)
> Me.Controls.Add(Me.Button1)
> Me.Name = "Form1"
> Me.Text = "WM_send"
> Me.ResumeLayout(False)
>
> End Sub
>
> #End Region
>
>
> Dim wndh As Integer 'handle to some app window
> Dim wndh2 As Integer
>
>
> 'Win32 api declarations
> Private Structure COPYDATASTRUCT
> Public dwData As Integer
> Public cbData As Integer
> Public lpData As Integer
> End Structure
>
> Const WM_COPYDATA As Int32 = &H4A
> Const EM_GETSEL As Int32 = &HB0
> Const EM_SETSEL As Int32 = &HB1
> Const EM_REPLACESEL As Int32 = &HC2
> Const WM_CHAR As Int32 = &H102
> Const WM_SETTEXT As Int32 = &HC
> Const WM_GETTEXT As Int32 = &HD
> Const WM_GETTEXTLENGTH As Int32 = &HE
> Const WM_CLOSE As Int32 = &H10
>
>
> Declare Function GetFocus Lib "user32" () As Long
> Declare Function SetFocus Lib "user32" (ByVal hwnd As Long) As Long
>
> Declare Function GetDlgCtrlID Lib "user32" (ByVal hwnd As Int32) As
> Int32
>
> Declare Function FindWindow Lib "user32.dll" Alias "FindWindowA"
> (ByVal lpClassName As String, ByVal lpWindowName As String) As Int32
>
> Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA"
> (ByVal hWnd1 As Int32, ByVal hWnd2 As Int32, ByVal lpsz1 As String,
> ByVal lpsz2 As String) As Int32
>
> Declare Function PostMessageByString Lib "user32" Alias
> "PostMessageA" (ByVal hwnd As Int32, ByVal wMsg As Int32, ByVal wParam
> As Int32, ByVal lParam As String) As Int32
>
> Declare Function SendMessage Lib "user32" Alias "SendMessageA"
> (ByVal hwnd As Int32, ByVal wMsg As Int32, ByVal wParam As Int32, ByVal
> ByVallParam As Int32) As Int32
>
> Declare Function SendMessageLong& Lib "user32" Alias "SendMessageA"
> (ByVal hwnd As Int32, ByVal wMsg As Int32, ByVal wParam As Int32, ByVal
> lParam As Int32)
>
> Declare Function SendMessageBystring Lib "user32" Alias
> "SendMessageA" (ByVal hwnd As Int32, ByVal wMsg As Int32, ByVal wParam
> As Int32, ByVal lParam As String) As Int32
>
> Declare Function SetWindowText Lib "User32.dll" Alias
> "SetWindowTextA" (ByVal hWnd As Int32, ByVal lpString As String) As
> Int32
>
>
>
> 'Button to send message
> Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
> System.EventArgs) Handles Button1.Click
>
> 'Get handle to app (wndh) and control within app (wndh2)
>
> wndh = FindWindow("JAMP WinConsole", "Jedi Knight Academy MP
> Console")
> wndh2 = FindWindowEx(wndh, 0, "Edit", vbNullString)
> wndh2 = FindWindowEx(wndh, wndh2, "Edit", vbNullString)
>
> SetFocus(wndh2)
>
> SendMessage(wndh2, EM_SETSEL, -1, -1)
> SendMessageBystring(wndh2, EM_REPLACESEL, 0, "say test")
> SendMessageLong(wndh2, WM_CHAR, 13, 0&)
>
> End Sub
>
>
> <END CODE>
>


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