Getting/Setting text from another program.

[Herpus Derpus]

How can I get/set text to/from another program's edit box?

E.G I type something into my browser's address bar then my program recieves it.

Or I type something into my program and and it puts that into the address bar.

[GhqjLyTq]

Get a handle to the edit box, then use GetWindowText to get the text from it, or SetWindowText to set the text.

[Herpus Derpus]

Example? ;D

[andywestken]

From MSDN entry for GetWindowText

Copies the text of the specified window's title bar (if it has one) into a buffer. If the specified window is a control, the text of the control is copied. However, GetWindowText cannot retrieve the text of a control in another application.

Note the last sentence.

But the same entry does go on to remark

To retrieve the text of a control in another process, send a WM_GETTEXT message directly instead of calling GetWindowText.

Andy

P.S. If your interested in the why, see: "The secret life of GetWindowText"
http://blogs.msdn.com/b/oldnewthing/archive/2003/08/21/54675.aspx

[webJose]

Yes, you must send the WM_GETTEXT message. As I recall, you need to allocate the buffer in the external application using VirtualAllocEx(), then use ReadProcessMemory() to import the result into your own address space.

[andywestken]

@webJose - I think the system handles the memory marshalling for you in the case of WM_GETTEXT and other standard messages.

From MSDN entry for SendMessage (ok, the logic is reversed, but...)

The system only does marshalling for system messages (those in the range 0 to (WM_USER-1)). To send other messages (those >= WM_USER) to another process, you must do custom marshalling.

[Herpus Derpus]

Could I have an example? All this is confusing

[andywestken]

This little applet finds the first notepad instance it can and dumps some of the text it's displaying.

Andy

// DumpNotepadText.cpp

#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <iostream>
using namespace std;

void DumpNotepadText()
{
	cout << "[DumpNotepadText]" << endl;

	cout << "- find Notepad window" << endl;
	HWND hwndNotepad = FindWindow("Notepad", NULL);

	if(NULL != hwndNotepad)
	{
		cout << "- find Edit control window" << endl;
		HWND hwndEdit = FindWindowEx(hwndNotepad, NULL, "EDIT", NULL);

		if(NULL != hwndEdit)
		{
			cout << "- get text length" << endl;
			int textLen = (int)SendMessage(hwndEdit, WM_GETTEXTLENGTH, 0, 0);

			if(0 < textLen)
			{
				cout << "- get text (up to 1024 chars, inc term null)" << endl;
				const int bufferSize = 1024;
				char textBuffer[bufferSize] = "";
				SendMessage(hwndEdit, WM_GETTEXT, (WPARAM)bufferSize, (LPARAM)textBuffer);

				cout << "[begin text]" << endl;
				cout << textBuffer     << endl;
				cout << "[end text]"   << endl;
			}
			else
			{
				cerr << "? No text there! :-(" << endl;
			}
		}
		else
		{
			cerr << "? Huh? Can't find Edit control!?!" << endl;
		}
	}
	else
	{
		cerr << "? No notepads open! :-(" << endl;
	}
}

int main()
{
	DumpNotepadText();

	return 0;
}

[DSLq5Di1]

I see, a fan of yoda syntax Andy, you are. Hmmmmmm. ~Yoda voice~

[andywestken]

Hmmm, yes. When padowan I was, taught I was the yoda way.

[Gz64jE8b]

What if there's more than one edit box?

[andywestken]

Then you'll have to be more cunning with the searching.

Either search by name, or search for the n'th edit box (FindWindowEx's 2nd param is hwndChildAfter -- the search begins with the next child window in the Z order.)

[Gz64jE8b]

Thanks, Andy. :)