Mega Code Archive
Check whether an application (window) is not responding
<![CDATA[
Title: check whether an application (window) is not responding?
// 1. The Documented way
{
An application can check if a window is responding to messages by
sending the WM_NULL message with the SendMessageTimeout function.
Um zu überprüfen, ob ein anderes Fenster (Anwendung) noch reagiert,
kann man ihr mit der SendMessageTimeout() API eine WM_NULL Nachricht schicken.
}
function AppIsResponding(ClassName: string): Boolean;
const
{ Specifies the duration, in milliseconds, of the time-out period }
TIMEOUT = 50;
var
Res: DWORD;
h: HWND;
begin
h := FindWindow(PChar(ClassName), nil);
if h 0 then
Result := SendMessageTimeOut(H,
WM_NULL,
0,
0,
SMTO_NORMAL or SMTO_ABORTIFHUNG,
TIMEOUT,
Res) 0
else
ShowMessage(Format('%s not found!', [ClassName]));
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
if AppIsResponding('OpusApp') then
{ OpusApp is the Class Name of WINWORD }
ShowMessage('App. responding');
end;
// 2. The Undocumented way
{
// Translated form C to Delphi by Thomas Stutz
// Original Code:
// (c)1999 Ashot Oganesyan K, SmartLine, Inc
// mailto:ashot@aha.ru, http://www.protect-me.com, http://www.codepile.com
The code doesn't use the Win32 API SendMessageTimout function to
determine if the target application is responding but calls
undocumented functions from the User32.dll.
-- For NT/2000/XP the IsHungAppWindow() API:
The function IsHungAppWindow retrieves the status (running or not responding)
of the specified application
IsHungAppWindow(Wnd: HWND): // handle to main app's window
BOOL;
-- For Windows 95/98/ME we call the IsHungThread() API
The function IsHungThread retrieves the status (running or not responding) of
the specified thread
IsHungThread(DWORD dwThreadId): // The thread's identifier of the main app's window
BOOL;
Unfortunately, Microsoft doesn't provide us with the exports symbols in the
User32.lib for these functions, so we should load them dynamically using the
GetModuleHandle and GetProcAddress functions:
}
// For Win9X/ME
function IsAppRespondig9X(dwThreadId: DWORD): Boolean;
type
TIsHungThread = function(dwThreadId: DWORD): BOOL; stdcall;
var
hUser32: THandle;
IsHungThread: TIsHungThread;
begin
Result := True;
hUser32 := GetModuleHandle('user32.dll');
if (hUser32 0) then
begin
@IsHungThread := GetProcAddress(hUser32, 'IsHungThread');
if Assigned(IsHungThread) then
begin
Result := not IsHungThread(dwThreadId);
end;
end;
end;
// For Win NT/2000/XP
function IsAppRespondigNT(wnd: HWND): Boolean;
type
TIsHungAppWindow = function(wnd:hWnd): BOOL; stdcall;
var
hUser32: THandle;
IsHungAppWindow: TIsHungAppWindow;
begin
Result := True;
hUser32 := GetModuleHandle('user32.dll');
if (hUser32 0) then
begin
@IsHungAppWindow := GetProcAddress(hUser32, 'IsHungAppWindow');
if Assigned(IsHungAppWindow) then
begin
Result := not IsHungAppWindow(wnd);
end;
end;
end;
function IsAppRespondig(Wnd: HWND): Boolean;
begin
if not IsWindow(Wnd) then
begin
ShowMessage('Incorrect window handle!');
Exit;
end;
if Win32Platform = VER_PLATFORM_WIN32_NT then
Result := IsAppRespondigNT(wnd)
else
Result := IsAppRespondig9X(GetWindowThreadProcessId(Wnd,nil));
end;
// Example: Check if Word is hung/responding
procedure TForm1.Button3Click(Sender: TObject);
var
Res: DWORD;
h: HWND;
begin
// Find Winword by classname
h := FindWindow(PChar('OpusApp'), nil);
if h 0 then
begin
if IsAppRespondig(h) then
ShowMessage('Word is responding!')
else
ShowMessage('Word is not responding!');
end
else
ShowMessage('Word is not open!');
end;
]]>