IF !CheckWin('My Application Window Title') oSplashScreen.Hide() RELEASE oSplashScreen CLOSE ALL MESSAGEBOX('My application is already running.'+CHR(13),0+48+4096,'Application Running') RETURN .F. ENDIF FUNCTION CheckWin LPARAMETERS tcAppName *** This function uses the creation of a named MUTEX to determine whether *** or not the application is already running. This function should be called *** near the top of the application's main program to create a named object *** that can be checked every time the application is started. If the named *** object exists, the function will try to activate the FoxPro running application. LOCAL lcMsg, lnAttributes, lnOwner, lcName, lnMutexHandle, lnhWnd, lnRelationship, lnStyle, llRetVal LOCAL lcAppName LOCAL lcAsserts lcMsg = '' lcAsserts = SET('ASSERTS') *SET ASSERTS ON IF EMPTY( NVL( tcAppName, '' ) ) RETURN .T. TEXT TO lcMsg NOSHOW Error checking to see if app is already running. ENDTEXT ASSERT .F. MESSAGE lcMsg SET ASSERTS &lcAsserts RETURN ENDIF lcAppName = UPPER( ALLTRIM( tcAppName ) ) + CHR( 0 ) *** Declare just API functions and constants #DEFINE SW_MAXIMIZE 3 #DEFINE ERROR_ALREADY_EXISTS 183 #DEFINE GW_HWNDNEXT 2 #DEFINE GW_CHILD 5 DECLARE INTEGER CreateMutex IN WIN32API INTEGER lnAttributes, INTEGER lnOwner, STRING @lcName DECLARE INTEGER GetProp IN WIN32API INTEGER lnhWnd, STRING @lcName DECLARE INTEGER SetProp IN WIN32API INTEGER lnhWnd, STRING @lcNam, INTEGER lnValue DECLARE INTEGER CloseHandle IN WIN32API INTEGER lnMutexHandle DECLARE INTEGER GetLastError IN WIN32API DECLARE INTEGER GetWindow IN USER32 INTEGER lnhWnd, INTEGER lnRelationship DECLARE INTEGER GetDesktopWindow IN WIN32API DECLARE BringWindowToTop IN Win32APi INTEGER lnhWnd DECLARE ShowWindow IN WIN32API INTEGER lnhWnd, INTEGER lnStyle *** Try and create a new MUTEX with the name of the passed application lnMutexHandle = CreateMutex( 0, 1, @lcAppName ) *** If the named MUTEX creation fails because it exists already, try to display *** the existing application IF GetLastError() = ERROR_ALREADY_EXISTS *** Get the hWnd of the first top level window on the Windows Desktop. lnhWnd = GetWindow( GetDesktopWindow(), GW_CHILD ) *** Loop through the windows. DO WHILE lnhWnd > 0 *** Is this the one that we are looking for? *** Look for the property we added the first time *** we launched the application IF GetProp( lnhWnd, @lcAppName ) = 1 *** Activate the app and exit stage left BringWindowToTop( lnhWnd ) ShowWindow( lnhWnd, SW_MAXIMIZE ) EXIT ENDIF lnhWnd = GetWindow( lnhWnd, GW_HWNDNEXT ) ENDDO *** Close the 'failed to open' MUTEX handle CloseHandle( lnMutexHandle ) ELSE *** Add a property to the FoxPro App so we can identify it again SetProp( _vfp.Hwnd, @lcAppName, 1) llRetVal = .T. ENDIF SET ASSERTS &lcAsserts CLEAR DLLS CreateMutex CLEAR DLLS GetProp CLEAR DLLS SetProp CLEAR DLLS CloseHandle CLEAR DLLS GetLastError CLEAR DLLS GetWindow CLEAR DLLS GetDesktopWindow CLEAR DLLS BringWindowToTop CLEAR DLLS ShowWindow RETURN llRetVal