Passing a parameter to VB and then using sendmessage

If WM_SETTEXT doesn't work then, you could try sending the string as individual characters using WM_KEYDOWN and WM_CHAR:

Imports System.Runtime.InteropServices
Public Class Form3
 
    Private Const WM_CHAR As Integer = &H102
 
    Private Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" _
        (ByVal parent As IntPtr, ByVal child As IntPtr, _
        ByVal className As String, ByVal caption As String) As IntPtr
 
    Public Declare Auto Function PostMessage Lib "user32.dll" ( _
        ByVal handle As IntPtr, ByVal wMsg As Integer, _
        ByVal wParam As Integer, ByVal lParam As Integer) As Integer
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim notepad As Process
 
        Dim ps() As Process = Process.GetProcessesByName("NotePad")
        If ps.Length = 0 Then
            notepad = Process.Start("NotePad")
            notepad.WaitForInputIdle()
        Else
            notepad = ps(0)
        End If
 
        Dim editHandle As IntPtr = FindWindowEx(notepad.MainWindowHandle, IntPtr.Zero, "Edit", "")
        Dim msg As String = "WM_CHAR works..."
        For Each c As Char In msg
            PostMessage(editHandle, WM_CHAR, Microsoft.VisualBasic.AscW(c), IntPtr.Zero)
        Next
    End Sub
 
End Class

Select allOpen in new window

Hi Idle Mind,

I've tried what you have said and this is where I'm at.  I can use sendmessage to click the button that I require on the application window, I can now use sendmessage to send a piece of text to the box that needs to be populated.  However when I put these onto the one button they do not work so from the form that I have developed I have to button's one to generate the window that needs to be populated and one then to pass the text.  I have attached the code below.  Thanks for your help.

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 
        SendMessageByString(TBitBtnEx, BM_CLICK, 0&, 0) 'Not sure if CStr is a function in VB7?'
 
    End Sub
 
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
 
        Call SendMessageByString(TPickList, WM_SETTEXT, IntPtr.Zero, "WM_SETTEXT works...")
 
    End Sub

Select allOpen in new window

Have you tried adding a delay between the two to allow the window to pop up?

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
         SendMessageByString(TBitBtnEx, BM_CLICK, 0&, 0)
         System.Threading.Thread.Sleep(1000)
         SendMessageByString(TPickList, WM_SETTEXT, IntPtr.Zero, "WM_SETTEXT works...")
    End Sub

Yeah I tried that without success, I've just tried it with your code and it was unsuccessful as well.  

It seems to be once completes the SendMessageByString(TBitBtnEx, BM_CLICK, 0&, 0) and generates the new window that it is looking for something else.  

The reason that I say this is because I cannot go back to Form 1 to click the other button but if I split the commands onto 2 seperate buttons then I can click the 1st button to generate the Account Lookup window and click the 2nd button to pass the text with no problems.

I wonder if PostMessage() instead of SendMessage() would make a difference...  =\

Do you know how to define it?

It should be declared exactly like SendMessage....just change "SendMessage" to "PostMessage".  =)

Hi Idle Mind, I did a bit of playing about and got it working through the use of the Postmessage followed by a delay and then the SendMessageByString.  Hopefully the rest of it will be a bit less tricky lol.  Thanks for your help.

You're welcome!

I was helping you in two of your other open questions...is this related to those as well?  ...or do I need to revisit those threads?

Yeah this is related to those as well but don't worry about them as I think I'll be able to fumble my way from here.  If I can't then I'll post a new thread.  Once again thanks a million for the help.

Excuse me, Is this code in C#?

That's VB.Net code...though you could easily use a free online converter to get it into C#.