Hi Louise,

Here is your code fixed.
What were the problems:

1. Wrong types were used for the API methods. Check the types that I use.
This is important because the stack frame that the managed code sends to the
API has to be what the target expects otherwise it gets wrong parameter
values.

2. I used Herfried K. Wagner version of MAKEWPARAM the reason being is that
using multiplication throws overflow exception with VB. I believe it can be
done that way, but I fill my self lost in VB types system and typecasting.

3. The reason why Notepad didn't receive any of the messages with your
version of the programwas that Notpad has one main top-level window and the
actual editor is a child of this main window. What you did is to send the
messages to the main window. It doesn't know what to do with them. You have
to send the messages to the edit window. You can check the windows structure
of Notepad with Spy++. What I do is I use GetWindow API to get the first
child of the main window. It happens that this is the edit window. But
actually the correct way would be to go thru all children and find the
correct one.

4. You don't send keyboard messages. Unlike the mouse messages where
probably is not a big of a difference if you send or post the msg, keyboard
messages have to be posted. The reason being is that in the message loop
usually there is TranslateMessage call that generates WM_CHAR for example or
call for generates shortcut events, etc. So, you post keyboard messages
rather than send them.

Take a look on the changes I've made. If you have more problems don't
hesitate to post them in the ng

Public Class Form1
   Inherits System.Windows.Forms.Form
   Private Declare Function SetActiveWindow Lib "user32" Alias
"SetActiveWindow" (ByVal hwnd As IntPtr) As IntPtr
   Private Declare Function SetForegroundWindow Lib "USER32" (ByVal hwnd As
IntPtr) As Boolean
   Private Declare Function SendMessage Lib "user32.dll" Alias
"SendMessageA" (ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As
Integer, ByVal lParam As Integer) As Long
   Private Declare Function PostMessage Lib "user32" Alias "PostMessageA"
(ByVal hwnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal
lParam As Integer) As Long
   Private Declare Function GetWindow Lib "user32" Alias "GetWindow" (ByVal
hwnd As IntPtr, ByVal uCmd As Integer) As IntPtr

   Const VK_P = &H50
   Const WM_KEYDOWN = &H100
   Const WM_KEYUP = &H101
   Const WM_RBUTTONDOWN = &H204
   Const WM_RBUTTONUP = &H205
   Const GW_CHILD = &H5

   Private Function MAKEPARAM(ByVal l As Int32, ByVal h As Int32) As Int32
       Return (l And &HFFFF) Or (h << 16)
   End Function

   'Private Function MAKEPARAM(ByVal LoWord As UInt16, ByVal HiWord As
UInt16) As UInt32
   '    Return LoWord Or (HiWord << 16)
   'End Function

   Public Structure NoteWindow
       Public handle As IntPtr
       Public process As process
   End Structure
   Public mywindow As NoteWindow
   Public myProcess As Process

#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
       myProcess = New Process
       mywindow = New NoteWindow

   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.
   <System.Diagnostics.DebuggerStepThrough()> Private Sub
InitializeComponent()
       Me.Button1 = New System.Windows.Forms.Button
       Me.Button2 = New System.Windows.Forms.Button
       Me.SuspendLayout()
       '
       'Button1
       '
       Me.Button1.Location = New System.Drawing.Point(24, 24)
       Me.Button1.Name = "Button1"
       Me.Button1.Size = New System.Drawing.Size(104, 40)
       Me.Button1.TabIndex = 10
       Me.Button1.Text = "Open Notepad"
       '
       'Button2
       '
       Me.Button2.Location = New System.Drawing.Point(24, 72)
       Me.Button2.Name = "Button2"
       Me.Button2.Size = New System.Drawing.Size(104, 40)
       Me.Button2.TabIndex = 11
       Me.Button2.Text = "Send Messages"
       '
       'Form1
       '
       Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
       Me.ClientSize = New System.Drawing.Size(176, 165)
       Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Button2,
Me.Button1})
       Me.Name = "Form1"
       Me.Text = "Form1"
       Me.ResumeLayout(False)

   End Sub

#End Region

   Friend WithEvents Button2 As System.Windows.Forms.Button
   Friend WithEvents Button1 As System.Windows.Forms.Button

   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
       myProcess.StartInfo.FileName = "Notepad.exe"
       myProcess.StartInfo.WindowStyle = ProcessWindowStyle.Normal
       myProcess.Start()
       myProcess.WaitForInputIdle()
       mywindow.process = myProcess
       mywindow.handle = myProcess.MainWindowHandle

   End Sub

   Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button2.Click
       Dim reslt As New Long
       Dim editBox As New IntPtr
       SetActiveWindow(mywindow.handle)
       SetForegroundWindow(mywindow.handle)
       editBox = IntPtr.Zero

       editBox = GetWindow(mywindow.handle, GW_CHILD)

       reslt = PostMessage(editBox, WM_KEYDOWN, MAKEPARAM(VK_P, 0),
MAKEPARAM(1, &H19))
       reslt = PostMessage(editBox, WM_KEYUP, MAKEPARAM(VK_P, 0),
MAKEPARAM(1, &HC019))
       reslt = PostMessage(editBox, WM_RBUTTONDOWN, MAKEPARAM(0, 0),
MAKEPARAM(10, 20))
       reslt = PostMessage(editBox, WM_RBUTTONUP, MAKEPARAM(0, 0),
MAKEPARAM(10, 20))

   End Sub
End Class

---
HTH
Stoitcho Goutsev (100) [C# MVP]