ComboBoxEx Control Example

To create a ComboBoxEx control specify WC_COMBOBOXEX as the window class. To register the class, set the ICC_USEREX_CLASSES flag in the dwICC member of the INITCOMMONCONTROLSEX structure.

To use item images, an image list is created and assigned to the control using the CBEM_SETIMAGELIST message. ComboBoxEx controls support up to three images for an item: one for its selected state, one for its nonselected state, and one for an overlay image.

For the app to display the images, download the imagefile zip folder and place the individual imagefile files in the code source directory

#include <windows.h>
#include <commctrl.h>

///ComboBoxEx Control Example
#define IDC_COMBOBOXEX 1
#define IDC_STATIC_ICON 2
#define IDC_STATIC_TEXT 3

#pragma comment(lib, "comctl32.lib")

void CreateComboEx();
HWND hwndComBoxEx,hwndStaticText,hwndStaticIcon;
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,LPSTR lpCmdLine, int nCmdShow)
{
WNDCLASSEX wc;
MSG msg;
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = 0;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wc.lpszMenuName = NULL;
wc.lpszClassName = TEXT("myWindowClass");
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
RegisterClassEx(&wc);
CreateWindowEx(WS_EX_CLIENTEDGE,TEXT("myWindowClass"),TEXT("ComboBoxEx Control"), WS_VISIBLE | WS_OVERLAPPEDWINDOW,CW_USEDEFAULT, CW_USEDEFAULT, 430, 200, NULL, NULL, hInstance, NULL);
while(GetMessage(&msg, NULL, 0, 0) > 0)
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}


LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
{
case WM_CREATE:
{
HINSTANCE hInstance = (HINSTANCE)GetModuleHandle(NULL);
HBITMAP bitmapicon;
// load common control class ICC_USEREX_CLASSES from the dynamic-link library (DLL).
INITCOMMONCONTROLSEX icex;
icex.dwSize = sizeof(INITCOMMONCONTROLSEX);
icex.dwICC = ICC_USEREX_CLASSES;
InitCommonControlsEx(&icex);
//create combo box
hwndComBoxEx = CreateWindowEx(0, WC_COMBOBOXEX, NULL,WS_BORDER | WS_VISIBLE |WS_CHILD | CBS_DROPDOWN,10,10, 200,100,hwnd,(HMENU)IDC_COMBOBOXEX,NULL,NULL);
//create static boxed. One for text the other to display images
hwndStaticIcon = CreateWindow(TEXT("static"), TEXT(""), WS_CHILD |SS_ICON| WS_VISIBLE,230, 15, 40, 40, hwnd, (HMENU)IDC_STATIC_ICON, NULL, NULL);
hwndStaticText = CreateWindow(TEXT("static"), TEXT(""), WS_CHILD |WS_VISIBLE,270, 15, 150, 40, hwnd, (HMENU)IDC_STATIC_TEXT, NULL, NULL);
//create custom font
HFONT font = CreateFont(30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, TEXT("Times New Roman"));
//Set font in both comboboxex and static box
SendMessage (hwndComBoxEx, WM_SETFONT, (WPARAM)font, TRUE);
SendMessage (hwndStaticText, WM_SETFONT, (WPARAM)font, TRUE);
//USed to set up items in ComboBoxEx control
COMBOBOXEXITEM cbei;
cbei.mask = CBEIF_TEXT | CBEIF_IMAGE| CBEIF_SELECTEDIMAGE;// Set the mask common to all items.
typedef struct {LPTSTR pszText;int iImage;int iSelectedImage;} ITEMINFO;
ITEMINFO IInf[] = {
{TEXT("Chilli"),0, 0 },
{TEXT("Mushroom"), 1, 1 },
{TEXT("Onion"), 2, 2},
{TEXT("Pineapple"), 3, 3},
{TEXT("Strawberry"),4, 4}};

//load BMP images from project folder and insert into image list im_list
HIMAGELIST im_list = ImageList_Create(32, 32,ILC_COLOR|ILC_MASK, 4, 0);
bitmapicon = (HBITMAP)LoadImage(NULL, TEXT("chilli.bmp"), IMAGE_BITMAP, 32, 32, LR_LOADFROMFILE);
ImageList_Add(im_list,bitmapicon,0);
bitmapicon = (HBITMAP)LoadImage(NULL, TEXT("mushroom.bmp"), IMAGE_BITMAP, 32, 32, LR_LOADFROMFILE);
ImageList_Add(im_list,bitmapicon,0);
bitmapicon = (HBITMAP)LoadImage(NULL, TEXT("onion.bmp"), IMAGE_BITMAP, 32, 32, LR_LOADFROMFILE);
ImageList_Add(im_list,bitmapicon,0);
bitmapicon = (HBITMAP)LoadImage(NULL, TEXT("pineapple.bmp"), IMAGE_BITMAP, 32, 32, LR_LOADFROMFILE);
ImageList_Add(im_list,bitmapicon,0);
bitmapicon = (HBITMAP)LoadImage(NULL, TEXT("strawberry.bmp"), IMAGE_BITMAP, 32, 32, LR_LOADFROMFILE);
ImageList_Add(im_list,bitmapicon,0);
SendMessage(hwndComBoxEx, CBEM_SETIMAGELIST, 0, (LPARAM)im_list);

//populate comboboxex with data
for(int iCnt=0;iCnt<5;iCnt++){
cbei.iItem = iCnt;
cbei.pszText = IInf[iCnt].pszText;
cbei.cchTextMax = sizeof(IInf[iCnt].pszText);
cbei.iImage = IInf[iCnt].iImage;
cbei.iSelectedImage = IInf[iCnt].iSelectedImage;
// Tell the ComboBoxEx items. Return FALSE if this fails.
if(SendMessage(hwndComBoxEx,CBEM_INSERTITEM,0,(LPARAM)&cbei) == -1)
return FALSE;
}
}

break;
case WM_COMMAND:
//checks combo box clicked
if((HWND)lParam ==hwndComBoxEx)
{
//detects selection change in comboxboxec
if ( HIWORD(wParam) == 5) {

/* Could be used just to get selected item and text
TCHAR strText[255];
LRESULT sel = SendMessage(hwndComBoxEx, CB_GETCURSEL, 0, 0);
SendMessage(hwndComBoxEx,CB_GETLBTEXT, sel,(LPARAM)strText);
*/

//used to obstain selected item data by sending CBEM_GETITEM to ComBoxEx
TCHAR buff[100];
COMBOBOXEXITEM info;
info.mask = CBEIF_TEXT| CBEIF_IMAGE| CBEIF_SELECTEDIMAGE;;
info.iItem = SendMessage( hwndComBoxEx, CB_GETCURSEL, 0, 0 );
info.pszText = buff;
info.cchTextMax = sizeof( buff );
SendMessage(hwndComBoxEx, CBEM_GETITEM, 0, (LPARAM)&info );

//get image list from comboboxex and extract selected individual image
HIMAGELIST im_list=(HIMAGELIST)SendMessage( hwndComBoxEx, CBEM_GETIMAGELIST, 0, 0 );
int im_index=info.iSelectedImage;
HICON selectedicon=ImageList_GetIcon(im_list,im_index, NULL );

//set up static box with selected text and image
SendMessage(hwndStaticIcon, STM_SETIMAGE, (WPARAM)IMAGE_ICON, (LPARAM)selectedicon);
SetWindowText(hwndStaticText, buff);

//redraw static text box after change
RECT rect;
GetClientRect(hwndStaticText, &rect);
InvalidateRect(hwndStaticText, &rect, TRUE);
MapWindowPoints(hwndStaticText, hwnd, (POINT *) &rect, 2);
RedrawWindow(hwnd, &rect, NULL, RDW_ERASE | RDW_INVALIDATE);

}
} break;
//change appearance of both static windows
case WM_CTLCOLORSTATIC:
{
if (GetDlgCtrlID((HWND)lParam) == IDC_STATIC_TEXT || GetDlgCtrlID((HWND)lParam) == IDC_STATIC_ICON)
{
HDC hdcStatic = (HDC)wParam;
SetTextColor(hdcStatic, RGB(255, 0, 0)); //set text color
return (LRESULT)GetStockObject(NULL_BRUSH);//set background to white
}
}
break;
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hwnd, msg, wParam, lParam);
}
return 0;
}