Read window text in another window, without mosue!

hi,

I need to read text or control's text from another application's windows. My application is operating from background (hidden), and try to read other application's window text. Also there is no mouse used, so i believe i can't use mouse hook or SetCapture API... etc for this matter.

So i guess i need to capture other windows' application control's text based on some supplied screen coordinates.

In this case how to read get the windows' handle based on the coordinates?? and subsequently obtained the text?? assuming that i know the other application's name.

Thanks.

It depends on the type of window, but you should be able to use Spy++ to find out about the window, and window structure used in that application. Then you can use FindWindow to find the window and child windows until you get to the window containing the text you want. Then you can use SendMessage and the HWND returned from FindWindow to get the text.

Take a look at the following thread for an example:
get a control's ID

You could use WindowFromPoint or ChildWindowFromPoint APIs just in case.

I'd be interested to know why you would want to do this.

I have found that a lot of people are asking questions such as this, and in fact they are trying to do something very unsafe in Windows.

Darwen.

Quote:

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Originally posted by RussG1
It depends on the type of window, but you should be able to use Spy++ to find out about the window, and window structure used in that application. Then you can use FindWindow to find the window and child windows until you get to the window containing the text you want. Then you can use SendMessage and the HWND returned from FindWindow to get the text.

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Hi RussG1,

Here are some information about the target application window which i want to capture screen/control's text of:-

the target application is a visual basic application and currently it only contains one main application window. The "structure" or layout of the target application(for example, where the target's area of text or control's lie) will be different depends on who i supplied my function to. I can't let him to spy on his own application and pass me all the information need in order for me to capture screen text on his application.,because he is a system integrator and i am selling my functions to him to complete the task. However, he can give me his information such as the area or control's ID of his application as parameter(s) to my function.

I also have the possibility of launching the target application window from my own application (i don know wheather this will help in achieving my goals). What i would want is to provide functions to other party so that he can call my VC++ function to capture a predefined screen area's text on his application.

appreciate your help.

!!ADDitional information: The target application and my function/library is running in an unmanned environment/PC.

These are not Html dialogs (or something similair), are they? (a web browser control, or similair?), as that would be completely different.

As kirants stated, WindowFromPoint or ChildWindowFromPoint APIs are a possibility if you can obtain a screen coordinate that falls within the control you want to capture the text from.

Also, if you know the ClassName and WindowName of the main application window and the control is a direct child of the main application window, you could access the control using it's Control ID, etc. You could also use EnumChildWindows to try and find the window the contains the control yourself.

The are a few different ways to do what you want (possibly using a combination of different API calls depending on the circumstances), all depending on what information you will know ahead of time, and the possible differences between how the application might be laid out (i.e. will the control you are trying to access always be a direct child of the main window, etc?).

It is hard for me to completlety understand what you need, as it seems strange that the end user would be using it to capture text from his own application (that they developed)? And that using the mouse is not an option (not necessarily for hooking or anything, but just to use to find a screen coordinate, etc).

The 3rd party target window currently has only one main application window. It is a VB application.

Now i had some simple codes to grab the text from this 3rd party windows., for beginning i just assume that the text appear in some windows controls such as static control, edit control, button text etc...

Code:

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....

POINT point={15,18};
HWND  mywnd=0;
HWND mychildwnd=0;

TCHAR mytext[100]={0x00};
::ScreenToClient(mywnd,&point);
mywnd=::FindWindow(0,"targetWindow");
mychildwnd=::ChildWindowFromPoint(mywnd,point);
::GetWindowText(mychildwnd,mytext,100);

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These code works on static controls, but not edit or button with text. I don't have any controls ID awailable from the target window as it is written with visual basic and supplied by 3rd party.
how can i subclass it? i noted subclassdlgitem only available in mfc?

Also, if i build the target window in VB, i can get the main window handle only, i created a label in the VB form, but i couldn't get this child window which is the label in VB. any idea??

Quote:

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originally posted by mce ...

The 3rd party target window currently has only one main application window. It is a VB application.
......
These code works on static controls

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the static control on vb applications cannot be grabbed like this, i wonder how did u do that...

when u run any spying utility like handle pickers on a VB Application the static texts are not recognised by that because they donot have any handles, i asked in CG in the VB forums about this, one of them replied that static texts in VB are drawings and are not conventional windows with handles, so no handles means how can u apply ::GetwindowText().

as for the original question about getting the text from a window without having any information is a lil tough one, i think that the coordinate values are very vulnerable a slight change can cause errors, the supplier has to supply some other info as well to make ur job done.
mmmm...!!! the ID thing about main window will be helpful if the window remains in the same instance if the window is closed and reopenned there are chances that ID's may differ.

it would be a great thing if someone comes up with this thing to sort out, if the original poster solves the mystry, share it with us here as well, (even in a very diplomatic manner who knows there are "company secrets" behind.)


cheers.

well, i actually mean static in VC++ program. it works for static control only. As for vb, i tried the staic label, and doesn't work.

ok, i found some info on this, i can use WM_GETTEXT, again this doesn't work for all controls, even though it works on edit control.

now, i really need something that works on practically every controls, be in application in VC or VB, or just any application, as long as there is a window.

if i launch the application from my main process, will it help in accessing the application windows controls from the process that launch it???

Quote:

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Originally posted by siawos
as for the original question about getting the text from a window without having any information is a lil tough one, i think that the coordinate values are very vulnerable a slight change can cause errors, the supplier has to supply some other info as well to make ur job done.
mmmm...!!! the ID thing about main window will be helpful if the window remains in the same instance if the window is closed and reopenned there are chances that ID's may differ.

cheers.

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Not exactly...
Currently i can only think of using coordinates supplied by the application developer. There have many application developers which means there are different windows., however each of them need to provide me a general set of their window information for me to grab any text or have full control of their application. I can have the option to launch their application as well.

So i believe this make the task much easier than having zero information on the target windows. My question is what kind of general informations actually i can request from the application developer in this case to make my task simple??

Quote:

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originally posted by mce...

My question is what kind of general informations actually i can request from the application developer in this case to make my task simple??

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you would have to devise a combination of things to determine that, no single property/value will do the job there.
possibilities cab be...

• window class name (vulnerable)
• ID(vulnerable)
• heirarchical information of the window, like parents and their properties.
• coordinate values (vulnerable)
  

all of them are vulnerable but be a bit manager sorta person and develop some kinda relations within them and make them behave as "one for all and all for one"...
cheers.

if i can launch the application from my process, how will that help?

secondly, as to the information you suggested, such as window class name, ID etc, does this apply in application that developed under VB? or by other languages?

Quote:

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Originally posted by siawos
you would have to devise a combination of things to determine that, no single property/value will do the job there.
possibilities cab be...

• window class name (vulnerable)
• ID(vulnerable)
• heirarchical information of the window, like parents and their properties.
• coordinate values (vulnerable)
  

all of them are vulnerable but be a bit manager sorta person and develop some kinda relations within them and make them behave as "one for all and all for one"...
cheers.

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May i know in what sense is window class name vulnerable? I used spy++ and note that the windows class name is not changing at all. Of course if the application developer decided to change the window control type (for example from static to edit), the window class name will get changed from static to edit other than this, i believe it will remain uchanged?

Further to this question, if i have two same class, such as two edit controls at the same level, how do i specify which edit control i am refering? or is this the vulnerability you mentioned?

Quote:

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originally posted by mce...
if i can launch the application from my process, how will that help?

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if u can launch the target application from ur process then u can easily get the top parent handle n then enumerate them.

Quote:

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originally posted by mce...

secondly, as to the information you suggested, such as window class name, ID etc, does this apply in application that developed under VB? or by other languages?

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am sure this works for VB but others i dont know exactly, that depends on the architecture that they are built on, i remember running Spy++ on a java application and i could get certain msgs...

Quote:

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originally posted by mce...


May i know in what sense is window class name vulnerable? I used spy++ and note that the windows class name is not changing at all. Of course if the application developer decided to change the window control type (for example from static to edit), the window class name will get changed from static to edit other than this, i believe it will remain uchanged?

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check TN001 in MSDN for what i mean here, and your point is also a valid one.
note the class name of a simple MDI or SDI generated by MFC wizard in two different instances u'll see the difference there.

What other controls are you not able to get working? (different contol's respond to different messages. A message that works with 1 control, will not necessarily work for another. The same message may have a different meaning for different controls)

I tried with a quick sample VB application I created to test with.
I added 2 Labels, 2 TextBoxes, and a Button, and was able to get the text of all of the controls.

BTW: To differentiate between 2 controls that are the same type, you need either the HWND of the control, the control's title (which may not be unique) or the control's Control ID. (You need something that is unique for that control, the HWND being the best candidate).

Again HTML dialogs, or web browser controls (or similair type of controls) work differently. You would have to use COM/DOM , etc with these type of controls.

If you are trying to build an application that will work (without modification) with all the different possible applications that the developers may build, that would be difficult as you would have to account for every type of control, and know what messages work with different types of controls, and try to figure out how to pull it all together.

There are probably better ways to do whatever it is you are going to be doing in the long run. Maybe the developers could develop the programs so that the controls can be accessed externally (through VBScript or similair), etc.

Some details would help:

What interface you have between the caller and the callee. Are you using some kind of dll ? It looks like you have 2 apps and one app is trying to get the text of controls in another app. What is not clear is what kind of inter process communication you use to pass stuff back and forth.

How would you get the text for a label within a form that is not its own window but to which you know its control ID? I am looking for a code example. Say the hwnd to the form was "h_form" and the control id for the label was "1276"

I assume you mean using VC++ code to get the text of a VB Label control.

h_form would have to be the HWND of the form.
The following code assumes the label control is a direct child of the form.

PHP Code:

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// get handle of Label Control
HWND hWnd = ::GetDlgItem(h_form, 1276);
// Get the length of the label's text
int Len = ::SendMessage(hWnd, WM_GETTEXTLENGTH, 0, 0);
// create variable to hold text (plus null terminator)
TCHAR * lpszText = new TCHAR[Len + 1];
// get the text
::SendMessage(hWnd, WM_GETTEXT, (WPARAM)Len+1, (LPARAM)lpszText);
// text is in lpszText, do something with text...
::MessageBox(NULL, lpszText, "Message", MB_OK);
// delete pointer
delete [] lpszText; 


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Quote:

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Originally posted by RussG1
What other controls are you not able to get working? (different contol's respond to different messages. A message that works with 1 control, will not necessarily work for another. The same message may have a different meaning for different controls)

I tried with a quick sample VB application I created to test with.
I added 2 Labels, 2 TextBoxes, and a Button, and was able to get the text of all of the controls.

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So far, from VB application,i can grab text for TextBox, ComboBox, Button.. from my VC++ application, across the process. All this i am using WM_GETTEXT to achieve the task.

Now, VERY INTERESTING!! interesting part is, this is not enough. I really need to be able to grab text from ListBox, MSFlexControl (an add in components available both in VB and VC++). I believe this controls doesn't process the WM_GETTEXT message.

So fro list box, i do the following, which works fine., i got back the text according to the index.

Code:

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ListBox_GetText(listboxHwnd, 1, Mybuffer);

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For ListView control, this doesn't work:-
The reason simply because the address of structure lvi is interpreted differently across the process.

Code:

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ListView_GetItem(listViewHwnd, &lvi);

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However, i can solve this problem by passing a pointer to a buffer that is relative to the remote process, initialize the pointer to the byte in the remotely allocated memory block using Read and Write ProcessMemory. This is a bit complicated, but that is ok, as long as i got what i want.

Now, the problem is with other controls such as MSFlexGrid Control. I can get the handle for this control, but how can i send a message to this remote control to ask him to do the task as in listView control, such as GetText, GetRows, GetColumns etc etc, the rest of the operations can be seen if you add this components into yout VC++ project, it created the Class called CMSFlexGrid. If you can provide some sample codes to me on how to get around this problem, i really appreciate.. it may not be easy, but i am getting very desperate now. Come to that, MSFlexGrid is actually an activeX, but i just don know how i can make use of this feature to get what i want.. i need some working examples.. really.

Quote:

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Originally posted by RussG1
Again HTML dialogs, or web browser controls (or similair type of controls) work differently. You would have to use COM/DOM , etc with these type of controls.

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Does this apply to the MSFlexGrid? it is an activex control, but again, if so, really appreciate your working samples..

Quote:

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Originally posted by RussG1
If you are trying to build an application that will work (without modification) with all the different possible applications that the developers may build, that would be difficult as you would have to account for every type of control, and know what messages work with different types of controls, and try to figure out how to pull it all together.

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That is what i plan to do, however, for now, i just want to have those common controls, label, and some uncommon one such as MSFlexGrid.. listbox etc. then i would be very happy already.

Quote:

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Originally posted by RussG1
There are probably better ways to do whatever it is you are going to be doing in the long run. Maybe the developers could develop the programs so that the controls can be accessed externally (through VBScript or similair), etc.

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Well, i can't think of better way now, i have totally no control of the application source or the way it is being developed. All i want is to support existing application with those common controls and a couple of uncommon controls such as MSFlexGrid.

Quote:

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Originally posted by RussG1
I assume you mean using VC++ code to get the text of a VB Label control.

h_form would have to be the HWND of the form.
The following code assumes the label control is a direct child of the form.

PHP Code:

---

// get handle of Label Control
HWND hWnd = ::GetDlgItem(h_form, 1276); 


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if i do not have the label ID, how? There is no windows handle in VB label.. it is not a windows class, is there a way out in this case??

I do not know much about the MSFlexGrid control. I have never used it. I can't even try it out, because I get an error about not having a design time license for it (something must have messed up when I upgraded to .NET). I do not not what type of messages it handles.

Try using Spy++ with Internet Explorer (click the find tool and drag it to a web page) so you can see what I mean abou the differences with a web browser control, etc.. The window that shows up in Spy++ will be class type "Internet Explorer_Server". You will notice that you do not see TextBoxes or any other elements that make up the web page. This is what I mean by html dialogs, or web browser controls (or similair). The content (i.e. textboxes within the web page) is html, thus they do not have window handles, etc, and will not show up it Spy++. You can access the data using Active Accessibility and the IHTMLDocument2 Interface , but it is more complicated.

When you look at the MSFlexGrid control in Spy++ what does it look like? (do you see all of the controls that make up that control?)

You can also use Spy++ to log all messages to window, so you might try doing that with the FlexGrid control to see some of the messages it handles, etc (if it is a regular window, and not like the "Internet Explorer_Server" window).

Quote:

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Originally posted by mce
if i do not have the label ID, how? There is no windows handle in VB label.. it is not a windows class, is there a way out in this case??

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What do you mean there is no windows handle?
Look at it is Spy++, and you will see the handle of the label control.

BTW: I noticed that with every VB control I looked at, the Handle and Control ID value was the same.

If you know the handle of the parent window, and you know the caption of the label (and if the caption is unique within the app), you can use FindWindowEx, to get the handle of the control by it's caption.

Also, note that you can use the GetWindowText API function to get the "Caption" of a control as well (this is not necessarly the same text you would get when sending the WM_GETTEXT message).

*edit*
BTW: The Class Name I get for the labels I used for testing is "WindowsForms10.STATIC.app1"

when i check with spy++, it brought me to

000204FC""MSFlexGridWndClass", there is no child class from it. so i suppose this is similar to web controls you said... how to "access this object" then... inside this control are actually columns and rows... i need to be able to "invoke methods" on this object, but i guess i can do it in a similar way like ListView where i would read and write process memory.

So i think my concern is how to send message to this beast to ask him like to return information to me?? how to find out the messages it handles?? i may not need to access or invoke its methods directly from a windows handle from another process, but i should be able to send messsage to him(which is in another process) to perform some of the methods it exposes..... i need you help...

Quote:

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Originally posted by RussG1
What do you mean there is no windows handle?
Look at it is Spy++, and you will see the handle of the label control.

BTW: I noticed that with every VB control I looked at, the Handle and Control ID value was the same.

*edit*
BTW: The Class Name I get for the labels I used for testing is "WindowsForms10.STATIC.app1"

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well, i guess the problem is that you are using VB.net and i am using VB6.0... if you create a form in VB6, you can't find any windows handle for label... drag the Spy++ eye over the label, nothing happen.... and all other controls have different handle values. ................

It is possible that you may by able to send messages to the MSFlexGridWndClass window to get the data you want. I do not know enough about that control to help much with that.

If it has a COM interface that you may be able to access through COM as well (I do not know a lot about COM either. I have only played around with it a little, but have been able to grab text from TextBoxes on a webage, change properties of the page, etc). You would get an IDispatch Interface to the control, and then use QueryInterface to find out what it supports, and you can invoke methods using those interfaces, etc. Though it is not as easy as it sounds. You would have to read about COM, and find out what type of Interfaces and methods that the control exposes for you to access, etc.

Again do not know enough about the FlexGrid control (or COM) to provide much help there...

Quote:

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Originally posted by mce
well, i guess the problem is that you are using VB.net and i am using VB6.0... if you create a form in VB6, you can't find any windows handle for label... drag the Spy++ eye over the label, nothing happen.... and all other controls have different handle values. ................

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Ahh, yeah that is probably it. It really did not use VB6 much (actually don't use VB much at all, since verison 4). Controls like that (if they are controls), probably can't be accessed directly through the Windows API, as there functionality is probably only in the VB Runtime libraries. Not sure how you would go about getting that text.

Quote:

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originally posted by mce...
Not sure how you would go about getting that text.

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i saw Mercury's WinRunner 5 not recognising that text either, its explicitely written in winrunner manuals that the text on VB applications cannot be recognised.

At my time My requirements were such that i stopped workking on that issue and headed towards others but i donot know your requirements so you have to decide.
I havent seen the latest version of Winrunner yet and i dont know whether it recognizes it or not...
as for the flexgrid control i think you can emulate the mouse clicks and get the results, (learnt that from Winrunner !!!)
if you have access to the interfaces or the messages used by that control then u can do that otherwise its a head scratcher.

One more thing if that could help, tools like winrunner and rational robot do a bit of same thing as u r trying to do they clearly say that only standard window controls will be recognised and if u(company) have their own controls developed then they require the control specs and they ship a patch for that to recognise these inhouse controls, and for that they "cost". This also holds for ActiveX controls.