Detecting total RAM change in Windows

Is there a callback in Windows 开发者_如何转开发which will notify my application if the total amount of System RAM has changed?

You might be able to do this via WMI, if you can pick up _InstanceCreationEvent and _InstanceDeletionEvent on class Win32_PhysicalMemory.

There is sample code here (WMI is a bear to use in C or C++, sorry - C# would be easier). Just make the query you listen on use Win32_PhysicalMemory rather than Win32_Process here:

hres = pSvc->ExecNotificationQueryAsync(
    _bstr_t("WQL"), 
    _bstr_t("SELECT * " 
        "FROM __InstanceCreationEvent WITHIN 1 "
        "WHERE TargetInstance ISA 'Win32_Process'"), 
    WBEM_FLAG_SEND_STATUS, 
    NULL, 
    pStubSink);

You'd also need a second call like this for __InstanceDeletionEvent detection.