今天在MSN的核心讨论组上看到两篇文章.讨论的乃是应用程序是否没有响应.原文如下:
> How is it possible to determine a process is "not responding" like NT Task
> Manager do?
The heuristic works only for GUI processes, and consists of calling
SendMessageTimeOut() with SMTO_ABORTIFHUNG.
>There is any API call to do the job, or this status is simply a deduction
>based on process counters, like that returned from call to GetProcessTimes
>API function?
Use SendMessageTimeout with a value of WM_NULL. That's all Task
Manager does to determine this AFAIK.
--
有理有理.当然,我这里还有一个UNDOCUMENTED函数,乃是其他的解决方案,NT和9X有个USER32.DLL的函数,IsHungAppWindow(NT)和IsHungThread(9X).使用起来简便无比.下面给出原型.
BOOL IsHungAppWindow (
HWND hWnd, // handle to main app's window
);
BOOL IsHungThread (
DWORD dwThreadId, // The thread's identifier of the main app's window
);
有了原型,连解释都不需要,好得不的了.:)不过调用时需要GetProcAddress.库里没有该函数.
****************************************
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.
}
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.EXE }
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 Windows 95/98/ME we call the IsHungThread() 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 NT/2000/XP the IsHungAppWindow() 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 Word 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;