How do I read cells of another program's TStringGrid control? - vb.net

Question

How can I extract items from other application's gridview? The class name of the control is TStringGrid.
I can get the handle of the TStringGrid window with FindWindowEx using these declarations:
<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function FindWindow( _
ByVal lpClassName As String, _
ByVal lpWindowName As String) As IntPtr
End Function
<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function FindWindowEx(ByVal parentHandle As IntPtr, _
ByVal childAfter As IntPtr, _
ByVal lclassName As String, _
ByVal windowTitle As String) As IntPtr
End Function
code:
Dim TheMainForm As Integer = FindWindow("form", "fname")
Dim GV As Integer = FindWindowEx(TheMainForm, 0, "TStringGrid", "")
How can I extract the items from GV (TStringGrid handle)?
(I have to finish this project by tomorrow.)

Answer 1

A Delphi string grid is not a windows control. It's a custom Delphi control. As such it doesn't respond to windows messages asking for its content. Without the source of the app you would need to reverse engineer the app to work out where the content is stored.
Realistically the most effective way to do this will be to inject a thread into the target application. That thread can then do the work of reading the information and can then use some IPC to get the data back to your VB process.
In order to do this you will, ideally, need:
Knowledge of the exact version of Delphi used to build the app.
A deep understanding of the Delphi compiler and RTL.
The Delphi VCL source code for TStringGrid.
I've no idea how you'll be able to synchronize your reading thread with the Delphi app.
Anyway, whilst what you ask for is, in theory possible, in reality it is completely impractical. The sensible solution is to ask the authors of the Delphi program to provide an automation interface.