?
Solved

How can I get a WinForms text control's text string, given a pointer to its CWnd.

Posted on 2014-09-16
6
Medium Priority
?
408 Views
Last Modified: 2014-09-20
I have a Winforms app whose window contains several controls.   From a separate MFC process I need to be able to retrieve the value of one of the text controls in the Winforms app.

I enumerate those controls to get a CWnd pointer for each  one.  That all works fine.

The window has several pushbuttons and several text controls.  On each pushbutton, when I call GetWindowText() I get the pushbutton's caption returned.  As expected.

However when I call GetWindowText() on a text object I get nothing back even though there is clearly a non-null string there.

I'm assuming that one cannot use GetWindowText()  on a Winforms text object but I don't know what I can use that would give me back the text that's stored within a text object.
0
Comment
Question by:allanephillips
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
6 Comments
 
LVL 25

Expert Comment

by:chaau
ID: 40327032
I think GetWindowText should work fine. Can you post some code, there could be a problem. Also, can you check that the windows class of your edit controls is a correct one. It should have a value similar to "WindowsForms10.EDIT.app.0.34f5582_r9_ad1" (ignore the last bit, it is always different). It must have "EDIT" in it
0
 
LVL 25

Expert Comment

by:chaau
ID: 40327048
Please note that for normal Winform Edit controls the EDIT window will be a child of the form. If the edit is a toggle EDIT (with up and down arrows) then it will be part of a composite control and the actual EDIT control will be one level below. Check the spy++ for the well know WinForms program below:A WinForm windowIts spy
0
 

Author Comment

by:allanephillips
ID: 40327084
Well the window class that I seem to be seeing is: "WindowsForms10.Window.8.app.0.202c666".  It sounds as though that is not the right one.

When I use spy++ I don't see any descendant window that has ".EDIT" in its class name so it may be that the window that spy++ shows that looks like an edit control really isn't one.
0
Get your Conversational Ransomware Defense e‑book

This e-book gives you an insight into the ransomware threat and reviews the fundamentals of top-notch ransomware preparedness and recovery. To help you protect yourself and your organization. The initial infection may be inevitable, so the best protection is to be fully prepared.

 
LVL 25

Accepted Solution

by:
chaau earned 1500 total points
ID: 40327089
it may as well be a "custom control". The developers of the WinForm app may have developed a custom control, or imported an OCX control (e.g. a mask edit control or something). In this case you need to explore some other options, like windows hooking
0
 
LVL 35

Expert Comment

by:sarabande
ID: 40328131
when using spy, you could "search" for the control by dragging the search icon of spy to the text control.

try to get the window handle of the parent window and the id of the text control. then you can do:

HWND hwndTextCtrl == ::GetDlgItem(hwndParent, id);
TCHAR text[1024] = { 0 };
int len = ::GetWindowText(hwndTextCtrl,  text, 1024);

Open in new window


note, the windows form uses utf-16 character set which is called UNICODE by MS. the mfc application might use 'multibyte character set' where the TCHAR is a single char. if that is the case and the GetWindowText returns a positive length but the text seems to be empty, you may try to using WCHAR instead of TCHAR and call the ::GetWindowTextL which could handle wide strings.

Sara
0
 

Author Closing Comment

by:allanephillips
ID: 40334845
The solution really just told me that there is likely no way to get at the data in what's probably a "Custom Control".   I guess I'll have to try to get the data using an OCR converter.
0

Featured Post

New benefit for Premium Members - Upgrade now!

Ready to get started with anonymous questions today? It's easy! Learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

What my article will show is if you ever had to do processing to a listbox without being able to just select all the items in it. My software Visual Studio 2008 crystal report v11 My issue was I wanted to add crystal report to a form and show…
Container Orchestration platforms empower organizations to scale their apps at an exceptional rate. This is the reason numerous innovation-driven companies are moving apps to an appropriated datacenter wide platform that empowers them to scale at a …
The goal of the video will be to teach the user the concept of local variables and scope. An example of a locally defined variable will be given as well as an explanation of what scope is in C++. The local variable and concept of scope will be relat…
The viewer will learn additional member functions of the vector class. Specifically, the capacity and swap member functions will be introduced.

801 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question