假设你要向一type属性为tform1的窗口发信息，可如下：
UserMessage:cardinal;
UserMessage := RegisterWindowMessage('System Wide User Defined Message');
SendMessage(FindWindow('TForm1','RegisterMessage Get Example'),
UserMessage, 0, 0);
var
hwd: HWND;
txt: pchar;
begin
txt := 'test';
hwd := FindWindowEx(FindWindow('NotePad',nil),0,'Edit',nil);
if hwd <> 0 then
begin
SendMessage(hwd, WM_SETTEXT, 0,lparam(txt));
end
else
showMessage('记事本没打开');
end;
procedure TForm1.Button1Click(Sender: TObject);
var
hwd: HWND;
txt: pchar;
i:integer;
begin
hwd := FindWindowEx(FindWindow('NotePad',nil),0,'Edit',nil);
if hwd = 0 then
begin
showMessage('记事本没打开');
exit;
end;
txt := '11这是一行中文';
for i:=1 to length(txt) do
postMessage(hwd, WM_char,ord(txt),1);
procedure TForm1.Button1Click(Sender: TObject);
var
wnd: Hwnd;
begin
wnd := FindWindow('notepad', nil);
if wnd<>0 then
begin
wnd := FindWindowEx(wnd,0,'Edit',nil);
PostMessage(wnd, WM_KEYDOWN, VK_F1, 0);
end
else ShowMessage('notepad not find');
end;
