If your target application isn't the foreground window, you need to use PostMessage
to send keystrokes to its window handle. You can get that window handle using FindWindow
. The code below sends the Enter key to a the text area in a running instance of Notepad (note it uses an additional FindWindowEx
to locate the memo area first). It was tested using both Delphi 2007 and Delphi XE4 (32-bit target) on Windows 7 64.
uses Windows;
procedure TForm1.Button1Click(Sender: TObject);
var
NpWnd, NpEdit: HWnd;
begin
NpWnd := FindWindow('Notepad', nil);
if NpWnd <> 0 then
begin
NpEdit := FindWindowEx(NpWnd, 0, 'Edit', nil);
if NpEdit <> 0 then
begin
PostMessage(NpEdit, WM_KEYDOWN, VK_RETURN, 0);
PostMessage(NpEdit, WM_KEYUP, VK_RETURN, 0);
end;
end;
end;
To find the window by title (caption) instead, you can just use the second parameter to FindWindow
. This finds a new instance of Notepad with the default 'Untitled' file open:
NpWnd := FindWindow(nil, 'Untitled - Notepad');
Note that this requires as exact match on the window title. An extra space before or after the -
, for instance, will cause the match to fail and the window handle to not be retrieved.
You can use both the window class and title if you have multiple instances running. To find the copy of Notepad running with Readme.txt
loaded, you would use
NpWnd := FindWindow('Notepad', 'Readme.txt - Notepad');
To find other applications, you'll need to use something like WinSpy or WinSight to find the window class names. (There are others also, such as Winspector or WinDowse (both of which are written in Delphi).)
Your comment mentions Calculator
; according to Winspector, the Calculator
main window is in a window class called CalcFrame
on Windows 7, and the area the numbers are displayed in is a Static
window (meaning it doesn't seem to receive keystrokes directly). The buttons are simply called Button
, so you'd have to loop through them using EnumChildWindows
looking for the individual buttons to identify them in order to obtain their handles.
(How to enumerate child windows is a separate question; you can probably find an example by searching here or via Google. If you can't, post a new, separate question about that and we can try to get you an answer.)
Here's a quick example of sending keys to Calculator after finding it by window class. It doesn't do anything useful, because it needs some time spent to identify different buttons and the keys that each responds to (and the proper combination of messages). This code simply sends 11Numpad+22 to the calculator window (a quick test showed that they were properly received and displayed, and that's about all the time I wanted to spend on the process).
uses Windows;
procedure TForm1.Button1Click(Sender: TObject);
var
NpWnd: HWnd;
begin
NpWnd := FindWindow('CalcFrame', nil);
if NpWnd <> 0 then
begin
PostMessage(NpWnd, WM_KEYDOWN, VK_NUMPAD1, 0);
PostMessage(NpWnd, WM_KEYDOWN, VK_ADD, 0);
PostMessage(NpWnd, WM_KEYDOWN, VK_NUMPAD2, 0);
end;
end;