Dynamic button controls [WIN32 API/c++/VS 2010]

[William Putnam]

I'm developing an application that finds devices on a network and creates a window in the main window for each device and their processor cores. I want the core buttons to toggle the number of cores being used on a given processor.

To create these windows, I detect the number of processors in the system, then create a new class instance in a vector. I do the same for the cores. In each processor class, there is a vector for each core and a vector for the buttons associated with it.

My problem is that while I have the buttons being created, I cannot figure out how to assign controls for them in the case switch. How would I define the commands for these buttons? I am assuming that I don't know the number of processors or machines, and I am creating these buttons when declaring a new class for the found processor.

[novacain]

When you create the buttons you will supply an ID as the HMENU param.

The WM_COMMAND msg will contain this ID as the loword of the wparam, so you should be able to match the BN_CLICKED by control IDs.

[William Putnam]

novacain, would I then declare the button like this:

HWND btn = CreateWindowExW(NULL,
        L"BUTTON",
        L"SET MANUAL",
        WS_VISIBLE|WS_CHILD|BS_DEFPUSHBUTTON,
        25,//x
        200,//y
        150,//width
        24,//height
        mainSysOpt,
        **ID GOES HERE**,
        GetModuleHandle(NULL),
        NULL);

or do I have to do this in the header file where I declare the other modules?

Also, I'm still having a hard time seeing the link between the button and the processor/core. Could you please clarify?

[novacain]

Yes, you may need to cast the ID to a HMENU (ie (HMENU)IDC_CORE1,)

You will need to add a method to check if the ID of in the WM_COMMAND message is from one of your 'core' buttons.

Please note this is coded from memory, so not in any way tested....

CASE WM_COMMAND:
int ControlID = LOWORD(wParam);
int MessageType = HIWORD(wParam);
int Processed = -1;
int Error = -1;
if(MessageType == BN_CLICKED)
{
     //check for CORE BUTTON ID
     Error = CheckCoreID(ControlID, &Processed);
     //check to see if we processed the button click (ie was one of the created CORE buttons)
     if(Processed == 1 && Error == 0)
     {
            return 0;//show we processed this button click
     }
     //else let the message fall into the normal COMMAND switch 
     SWITCH (ControlID)
     {
           CASE IDC_ANOTHER_CTRL:

//etc


//CORE BUTTON HANDLER
//returns 0 for success, non zero on error
//sets ProcResult = 1 if we find CntrlId is one of the created CORE buttons
 
int CheckCoreID(int CntrlId, int *ProcResult)
{
     //run through the IDs in the CORE vector looking for the button ID
     //if we find the ID
          //process 
          //set the 'ProcResult' variable to show we have processed the button click

    return 0;//else return non zero on error
}

Another way is to assume a maximum number of cores per CPU (ie 8) and design a 'standard' or default dialog / window in the resource editor with this max number of buttons (ie create a dialog with 8 buttons).

Remove the WS_VISIBLE style from these buttons (so they do not appear) and add the visible style to the required buttons once you know how many cores a given CPU has (using ShowWindow() ).

Your callback would have a WM_COMMAND handler for each of these 'core' buttons (as with 'normal' buttons / controls), but only the visible ones will be able to generate BN_CLICKED messages.

You would then match the ID in the CORE vector to determine the required processing.