If I have the hWnd of a textbox how do I get it's text?

       
Public Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long

Public Const WM_GETTEXT = &HD



code:
        dim buffer as string

        Buffer = String(255, Chr(0))
        SendMessage hwnd, WM_GETTEXT, 255, Buffer
        Buffer = Left(Buffer, InStr(1, Buffer, Chr(0)) - 1)

BrianGEFF719,

         I make a new projet and put two textboxes on a form, Then I drop this code in. The only thing I get is a crash of the app. What am I doing wrong?



Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Const WM_GETTEXT = &HD

Private Sub Form_Load()
    Dim Txt1_hWnd As Long
    Txt1_hWnd = Text1.hwnd
    Text1.Text = "This is a text"

    'Your Code
              Dim buffer As String
              buffer = String(255, Chr(0))
              Call SendMessage(Txt1_hWnd, WM_GETTEXT, 255, buffer)
              buffer = Left(buffer, InStr(1, buffer, Chr(0)) - 1)
    'End Your Code

    Text2.Text = buffer
End Sub

I dont think you can do it from your own program, try a different text box that is not owned by your application.


-Brian

Actually, that’s exactly what I’m trying to do. I used the code only to simplify the problem. Can you write an example that will work? I’m changing the points to 500 because I feel this is more challenging than I first though.

I forgot to put dims for 2 lines: add dims !


Dim s As String
Dim  q As Integer

OMG!!!

It took me a couple of hours to find out why this example code crashes!
Change the following line:
     q = SendMessage(Text1.hwnd, WM_GETTEXT, 254, s$)
to
     q = SendMessage(Text1.hwnd, WM_GETTEXT, 254, ByVal s$)

If you do not pass it "ByVal", your app will crash when you make this call.  

:-)
--Nathan