IAPI::WaitForDirectoryChangeNotification

property WaitForDirectoryChangeNotification.

Watches any change within a directory (aka subdirectories and files changes)

This property is useful for monitoring any change into a directory and its subtrees, so a trigger program

can start accordingly with this notification.

HRESULT WaitForDirectoryChangeNotification(
 BSTR dirName,
 long NotificationHandle,
 long freeNotificationHandle,
 long *pVal
);

Parameters

dirName

[in] . Full directory name (e.g c:\windows)

NotificationHandle

[in,defaultvalue(0)]

. 0 if first call of the property which instantiates and initializes the handle of change.

. Handle value if subsequent calls

freeNotificationHandle

[in,defaultvalue(0)]

. 0 or geater if reuse the handle.

The value will then be used as a timeout in seconds to wait and yield control to client code.

(if 0 the timeout will be 15 seconds)

. -1 to free the handle and close the notification.

pVal

[out, retval]

The returned value is a handle of change notification for the directory if any change happened.

For the second and subsequent calls, the value 0 means the timeout without any changes

found into the directory.

Example of a ready-to-use scenario:

Const targetDirectory = "C:\APIDev"

Dim changeCounter

Dim ScriptEZ

Main()

Sub Main()

Set ScriptEZ = WScript.CreateObject("ScriptEZ.API","ScriptEZ_")

ScriptEZ.AppRegister

changeCounter = 0

notificationHandle = ScriptEZ.WaitForDirectoryChangeNotification(targetDirectory,0,0)

If notificationHandle > 0 Then

hThreadPool = ScriptEZ.CreateTaskQueueObject(1)

r = ScriptEZ.AddTask(hThreadPool,notificationHandle)

End If

Do while (true)

Wscript.Sleep 1000

Loop

End Sub

Function ScriptEZ_onRun(localStorage)

'-- Waiting and yielding control every 7 seconds

r = ScriptEZ.WaitForDirectoryChangeNotification("",localStorage,7)

If r > 0 And changeCounter = 0 Then

ScriptEZ.Echo CStr(Time) + " - onChange : " + CStr(changeCounter)

changeCounter = 1

ElseIf r = 0 And changeCounter > 0 Then

ScriptEZ.Echo CStr(Time) + " - Changes occurred into " + targetDirectory + _

" => triggering a program"

'--running a program here...

changeCounter = 0

End If

ScriptEZ_onRun = CLng(1) '--running again and again

End Function

Return Values

S_OK

The operation was successfull.

E_POINTER

A NULL pointer was supplied as an argument.

E_UNEXPECTED

An unexpected error occoured.

See Also

IAPI