Reading from a text field in another application's window

Question

Is there a way for a Windows application to access another applications data, more specifically a text input field in GUI, and grab the text there for processing in our own

Answer 1

Yes it is possible in many ways (one way is to use WINAPI GetWindow and GetWindowText).

First, get a handle to the textbox you want to retrieve text from (using FindWindow, EnumChildWindows and other APIs), then:

Old VB6-codeexample, declaration of API:

Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long  
Private Declare Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLengthA" (ByVal hwnd As Long) As Long  

Code to extract text:

Dim MyStr As String
MyStr = String(GetWindowTextLength(TextBoxHandle) + 1, Chr$(0))
GetWindowText TextBoxHandle, MyStr, Len(MyStr)
MsgBox MyStr