Delphi, how to switch to another application if it is running 1

[mhorvat]

Hello,

I have problem with switching to another application from my own. For example I would like to switch to notepad if it is open. Not to open with shell execute a new instance of application.

I already tried all kind of api calls or messages but with no success.

Any help would be welcome...

thanks

 

[Glenn9999]

var
  npadhandle: HWnd;
begin
  npadhandle := FindWindow('Notepad', nil);
  if npadhandle <> 0 then
    begin
      SetForegroundWindow(npadhandle);
      SendMessage(npadhandle, WM_SYSCOMMAND, SC_RESTORE, 0)
    end
  else
    Showmessage('Notepad not found.');
end;

It is not possible for anyone to acknowledge truth when their salary depends on them not doing it.

 

[mhorvat]

Is it possible to do this if have only process id or process name?

 

[DrZogg]

You need to use Process Explorer to know the window name, as well as get the process ID

 

[DrZogg]

to see if a process exists:

function TFrmKDSSwitch.processExists(exeFileName: string): Boolean;
{Uses TlHelp32}
var
ContinueLoop: BOOL;
FSnapshotHandle: THandle;
FProcessEntry32: TProcessEntry32;
begin
FSnapshotHandle := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
FProcessEntry32.dwSize := SizeOf(FProcessEntry32);
ContinueLoop := Process32First(FSnapshotHandle, FProcessEntry32);
Result := False;
while Integer(ContinueLoop) <> 0 do
begin
if ((UpperCase(ExtractFileName(FProcessEntry32.szExeFile)) =
UpperCase(ExeFileName)) or (UpperCase(FProcessEntry32.szExeFile) =
UpperCase(ExeFileName))) then
begin
Result := True;
end;
ContinueLoop := Process32Next(FSnapshotHandle, FProcessEntry32);
end;
CloseHandle(FSnapshotHandle);
end;

You call it depending on what the process name is

if not processExists('WBVod.exe') then
begin
SetCurrentDir('c:\Program Files\Wizbang\Waiter\WBVod');
shellexecute(Handle, 'open', 'c:\Program Files\Wizbang\Waiter\WBVod\WBVod.exe', nil, nil, SW_SHOWNORMAL) ;
end;