DdeSetQualityOfService
The DdeSetQualityOfService
function specifies the quality of service a raw DDE application desires for
future DDE conversations it initiates. The specified quality of service applies
to any conversations started while those settings are in place. A DDE
conversation s quality of service lasts for the duration of the conversation; calls
to the DdeSetQualityOfService function during a given conversation do
not affect that conversation s quality of service.
BOOL DdeSetQualityOfService(
|
HWND hwndClient, |
// handle to DDE
client window that will start DDE conversations |
|
CONST SECURITY_QUALITY_OF_SERVICE *pqosNew, |
// desired quality
of service |
|
PSECURITY_QUALITY_OF_SERVICE pqosPrev |
// prior quality of
service |
|
); |
|
Parameters
hwndClient
Identifies
the DDE client window that specifies the source of WM_DDE_INITIATE messages a client will send to
start DDE conversations.
pqosNew
Points to a SECURITY_QUALITY_OF_SERVICE structure for the desired
quality of service values.
pqosPrev
Points to a SECURITY_QUALITY_OF_SERVICE
structure that the function will fill with the previous quality of service
values associated with the window identified by hwndClient.
This
parameter is optional. If an application has no interest in hwndClient s
previous qos values, it should set pqosPrev to NULL.
Return Values
If the
function succeeds, the return value is nonzero.
If the
function fails, the return value is zero. To get extended error information,
call GetLastError.
Remarks
If a quality
of service has not been specified for a given client window, hwndClient,
prior to sending a WM_DDE_INITIATE with the wParam set to hwndClient,
the system uses the following default quality of service values for the client
window:
{
Length =
sizeof(SECURITY_QUALITY_OF_SERVICE);
ImpersonationLevel = SecurityImpersonation;
ContextTrackingMode
= SECURITY_STATIC_TRACKING;
EffectiveOnly = TRUE;
}
Use the DdeSetQualityOfService
function to associate a different quality of service with the client window.
Once you change the quality of service, the new settings affect any subsequent
conversations that are started. Once an application starts a DDE conversation
using a particular quality of service value, it must terminate the conversation
and restart the conversation in order to have a different value take effect.
See Also