Question

I am trying to use a context menu I created for a Dialog Box, but the WM_COMMAND message which is supposed to be sent when I click a menu item is not reaching the Dialog Procedure.

I put an if statement in the message loop to check for WM_COMMAND, and it is being registered but not being sent to my Dialog Procedure.

Yes, I am using if( !IsDialogMessage( hwndListDialog, &msg ) ) to call TranslateMessage and DispatchMessage.

This is how I initialised my context menu:

listitemmenu = CreatePopupMenu();

listmenuitem1.cbSize = sizeof( menuitem1 );
listmenuitem1.fMask = MIIM_TYPE;
listmenuitem1.fType = MFT_STRING;
listmenuitem1.hSubMenu = NULL;
listmenuitem1.dwTypeData = "Copy Imgur Link";
InsertMenuItem( listitemmenu, 0, true, &listmenuitem1 ); //insert menu item

listmenuitem2.cbSize = sizeof( menuitem1 );
listmenuitem2.fMask = MIIM_TYPE;
listmenuitem2.fType = MFT_STRING;
listmenuitem2.hSubMenu = NULL;
listmenuitem2.dwTypeData = "Copy Imgur Delete Link";
InsertMenuItem( listitemmenu, 1, true, &listmenuitem2 ); //insert menu item

listmenuitem3.cbSize = sizeof( menuitem1 );
listmenuitem3.fMask = MIIM_TYPE;
listmenuitem3.fType = MFT_STRING;
listmenuitem3.hSubMenu = NULL;
listmenuitem3.dwTypeData = "Rename";
InsertMenuItem( listitemmenu, 2, true, &listmenuitem3 ); //insert menu item

listmenuitem4.cbSize = sizeof( menuitem1 );
listmenuitem4.fMask = MIIM_TYPE;
listmenuitem4.fType = MFT_STRING;
listmenuitem4.hSubMenu = NULL;
listmenuitem4.dwTypeData = "Remove from list";
InsertMenuItem( listitemmenu, 3, true, &listmenuitem4 ); //insert menu item

This is how I track the menu:

TrackPopupMenuEx( listitemmenu, TPM_LEFTBUTTON | TPM_NOANIMATION | TPM_HORIZONTAL | TPM_VERTICAL, cpos.x, cpos.y, ListControl, NULL );

This is the switch case that I am trying to use to interact with my menu:

case WM_COMMAND:
        switch( LOWORD(lParam) )
        {
        case 0:
            printf("copy link");
            break;
        case 1:
            printf("copy deletion link");
            break;
        case 2:
            printf("Rename");
            break;
        case 3:
            printf("Remove");
            break;
        }
        break;

Answer 1

From the documentation for TrackPopupMenuEx:

hwnd [in]

Type: HWND

A handle to the window that owns the shortcut menu. This window receives all messages from the menu.

You passed ListControl as the hwnd parameter, so the WM_COMMAND is going to that window, not your dialog box. If you want the WM_COMMAND to go to your dialog box, then pass your dialog box as the hwnd.