Jak sprawdzić czy zmieniła się pozycja w ComboBox (WinAPI)
Na bazie szablonu z Dev C++ (gotowiec)
#include <windows.h> /* Declare Windows procedure */ LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM); /* Make the class name into a global variable */ char szClassName[ ] = "WindowsApp"; int WINAPI WinMain (HINSTANCE hThisInstance, HINSTANCE hPrevInstance, LPSTR lpszArgument, int nFunsterStil) { HWND hwnd; /* This is the handle for our window */ MSG messages; /* Here messages to the application are saved */ WNDCLASSEX wincl; /* Data structure for the windowclass */ /* The Window structure */ wincl.hInstance = hThisInstance; wincl.lpszClassName = szClassName; wincl.lpfnWndProc = WindowProcedure; /* This function is called by windows */ wincl.style = CS_DBLCLKS; /* Catch double-clicks */ wincl.cbSize = sizeof (WNDCLASSEX); /* Use default icon and mouse-pointer */ wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION); wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION); wincl.hCursor = LoadCursor (NULL, IDC_ARROW); wincl.lpszMenuName = NULL; /* No menu */ wincl.cbClsExtra = 0; /* No extra bytes after the window class */ wincl.cbWndExtra = 0; /* structure or the window instance */ /* Use Windows's default color as the background of the window */ wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND; /* Register the window class, and if it fails quit the program */ if (!RegisterClassEx (&wincl)) return 0; /* The class is registered, let's create the program*/ hwnd = CreateWindowEx ( 0, /* Extended possibilites for variation */ szClassName, /* Classname */ "Windows App", /* Title Text */ WS_OVERLAPPEDWINDOW, /* default window */ CW_USEDEFAULT, /* Windows decides the position */ CW_USEDEFAULT, /* where the window ends up on the screen */ 544, /* The programs width */ 375, /* and height in pixels */ HWND_DESKTOP, /* The window is a child-window to desktop */ NULL, /* No menu */ hThisInstance, /* Program Instance handler */ NULL /* No Window Creation data */ ); /* Make the window visible on the screen */ ShowWindow (hwnd, nFunsterStil); /* Run the message loop. It will run until GetMessage() returns 0 */ while (GetMessage (&messages, NULL, 0, 0)) { /* Translate virtual-key messages into character messages */ TranslateMessage(&messages); /* Send message to WindowProcedure */ DispatchMessage(&messages); } /* The program return-value is 0 - The value that PostQuitMessage() gave */ return messages.wParam; } /* This function is called by the Windows function DispatchMessage() */ LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { static HWND cb_handle = 0; static int pozycja_3 = 0; switch (message) /* handle the messages */ { case WM_CREATE: //tworzymy combo boxa cb_handle = CreateWindowEx(0,"COMBOBOX","",WS_CHILD | WS_VISIBLE | WS_VSCROLL | CBS_DROPDOWNLIST,20,20,150,22*4,hwnd,NULL,((LPCREATESTRUCT)lParam)->hInstance,NULL); //i zachowujemy uchwyt, lepsza metoda jest pod numerze komponentu - tu jednak dla uproszczenia //i dodajemy kilka pozycji SendMessage(cb_handle, CB_ADDSTRING,0, (LPARAM)"1"); SendMessage(cb_handle, CB_ADDSTRING,0, (LPARAM)"2"); pozycja_3 = SendMessage(cb_handle, CB_ADDSTRING,0, (LPARAM)"3"); SendMessage(cb_handle, CB_ADDSTRING,0, (LPARAM)"4"); //send message zwraca nam numery pozycji. UWAGA inserty i delety moga nam to zmienic ! //w tej kolejnosci bedzie OK jesli nic nie zmienimy ! Lepiej rozpoznawac po wartosci. break; case WM_COMMAND: //rozpoznajemy czy nasz komponent wyslal jakis komunikat. //Rozpoznajemy go po uchwycie (mozna po ID jak wspomnialem WM_CREATE) //My czekamy na to, az user skonczy wybieranie danej pozycji, odpowiada za to komunikat //CBN_SELENDOK. if (lParam == (LPARAM)cb_handle && HIWORD (wParam) == CBN_SELENDOK) { //jesli wybor sie zmienil to sprawdzamy jaka aktualnie //pozycja jest wybrana int iIndex = SendMessage(cb_handle, CB_GETCURSEL, 0, 0); //i jesli to pozycja 3 wyswietlamy komunikat if (pozycja_3 == iIndex) { MessageBox(hwnd,"Jupiiiii pozucja 3 zaznaczona !","", 0); } } break; case WM_DESTROY: PostQuitMessage (0); /* send a WM_QUIT to the message queue */ break; default: /* for messages that we don't deal with */ return DefWindowProc (hwnd, message, wParam, lParam); } return 0; }
