CPL_NEWINQUIRE (Compact 2013)
3/28/2014
This message is sent to a Control Panel application to request information about a dialog box that the application supports.
Syntax
CPL_NEWINQUIRE uAppNum = (UINT) lParam1;
lpncpli = (LPNEWCPLINFO) lParam2;
Parameters
- uAppNum
Dialog box number. This number must be in the range zero through one less than the value returned in response to the CPL_GETCOUNT message (CPL_GETCOUNT -1).
- lpncpli
Long pointer to a NEWCPLINFO structure. The Control Panel application should fill this structure with information about the dialog box.
Return Value
Zero indicates that the CPlApplet function processes this message successfully.
Remarks
The Control Panel sends the CPL_NEWINQUIRE message once for each dialog box supported by the application. The Control Panel also sends a CPL_INQUIRE message for each dialog box. These messages are sent immediately after the CPL_GETCOUNT message. However, the system does not guarantee the order in which the CPL_INQUIRE and CPL_NEWINQUIRE messages are sent.
You can perform initialization for the dialog box when you receive CPL_INQUIRE. If you must allocate memory, do so in response to the CPL_INIT message.
The CPL_NEWINQUIRE message was introduced in Windows version 3.1 as a replacement for CPL_INQUIRE. However, CPL_INQUIRE is the preferred message for Windows 95 and Windows NT version 4.0. This is because CPL_NEWINQUIRE returns information in a form that the system cannot cache. Consequently, applications that process CPL_NEWINQUIRE must be loaded each time the Control Panel needs the information, resulting in a significant reduction in performance.
The only applications that should use CPL_NEWINQUIRE are those that need to change icon or display strings based on the state of the computer. In this case, your CPL_INQUIRE handler should specify the CPL_DYNAMIC_RES value for the idIcon, idName, or idInfo members of the CPLINFO structure, rather than specifying a valid resource identifier. This causes the Control Panel to send the CPL_NEWINQUIRE message each time it needs the icon and display strings, allowing you to specify information based on the current state of the computer. Of course, this is significantly slower than using cached information.
Requirements
Header |
cpl.h |