如何在Win32中使用位圖創建組合框？

Question

我想創建一個這樣的自定義組合框（就像在MS Word中一樣），

是否有Win32 API調用（我不能使用MFC）來完成此工作（例如ChooseColor（）或ChooseFont（）？），如果沒有，請告訴我該怎么做？謝謝。

問候，

編輯：創建所有者繪制對話框！ 這是唯一的方法嗎？ http://msdn.microsoft.com/zh-cn/library/bb775794%28VS.85%29.aspx#creating_square_meal

Answer 1

您可以選擇一些解決方案：

1. 所有通用控件都支持WM_SETFONT ，因此，如果找到具有所需所有行元素的字體，則可以更改組合框控件的字體並用相應的文本填充項目。
2. 有ComboBoxEx控件，它將圖像與文本結合在一起（請參閱http://msdn.microsoft.com/zh-cn/library/bb775738(VS.85).aspx ）。 請注意，將選擇項目的哪一部分（只需嘗試一下）。 如果您可以稍微更改對組合框控件的要求，則可以使用它。
3. 您可以使用所有者繪圖組合框。 這樣，您就可以完全自由了，但是您的代碼可以更長一些，並且如果您使用非標准的Windows彩色shema或非默認的theams，則應該更加謹慎。 在這種情況下，建議您使用GetSysColor函數。

您應該決定自己的方式是最適合您的項目要求的方式。

Answer 2

您可以從WTL :: CComboBox派生。 您必須實現以下消息處理程序

• WM_MEASUREITEM / OCM_MEASUREITEM進行組合框項目的尺寸測量
• WM_DRAWITEM / OCM_DRAWITEM自己做圖。 您實際上並不需要位圖，只需使用GDI進行繪制即可。

Answer 3

在Win32中，這稱為所有者繪制的組合框。 在線試題的一個很好的起點是：

http://msdn.microsoft.com/zh-cn/library/bb775794%28VS.85%29.aspx#creating_owner_drawn

Answer 4

這是所有者繪制的組合框的工作代碼，其中包含說明。

// List image Icon Test.cpp : Defines the entry point for the application.
//

// READ ME:
// Create a new c++ desktop application
// Remove all the code from the cpp section and insert all this code.
// Create a dialog in VS editor, which had a list box called IDLIST and a combobox called IDCOMBO
// it will already have ok and cancel buttons these can stay.
// Create 4 bitmaps any size, only 24x24 will be shown and put them in the source project directory,
// eg C:\Users\Pts1\source\repos\List image Icon Test\List image Icon Test
// Rename the bitmaps Black.bmp, Blue.bmp, Red.bmp, Green.bmp and make sure they are of the format bmp not just called bmp.
// or ideally create the bitmaps so that they are 24x24 and all black,blue etc
// add IDB_Bread bitmap to the editor or remove them from the code below as instructed. We can load bitmaps directly from file instead.
// Make sure you change the combobox properties as instructed at the header for the dialog callback procedure.
//
#include "stdafx.h"
#include "List image Icon Test.h"
#include "strsafe.h"

#pragma comment(linker, "\"/manifestdependency:type='Win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")

#define MAX_LOADSTRING 100

#define ID_BREAD 0
#define ID_DAIRY 1
#define ID_FRUIT 2
#define ID_MEAT  3

#define CX_BITMAP 24
#define CY_BITMAP 24

HBITMAP hbmBread, hbmDairy, hbmMeat, hbmFruit, hbmMask, hbmIcon;

HINSTANCE hInst;                                // current instance
WCHAR szTitle[MAX_LOADSTRING];                  // The title bar text
WCHAR szWindowClass[MAX_LOADSTRING];            // the main window class name

ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
INT_PTR CALLBACK    About(HWND, UINT, WPARAM, LPARAM);

void InitGroupList(HWND hDlg);
void DeleteIconBitmaps(void);
BOOL LoadIconBitmaps(void);
void InitFoodList(HWND hDlg);
INT_PTR CALLBACK FoodDlgProc(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam);

int APIENTRY wWinMain(_In_ HINSTANCE hInstance,
                     _In_opt_ HINSTANCE hPrevInstance,
                     _In_ LPWSTR    lpCmdLine,
                     _In_ int       nCmdShow)
{
    UNREFERENCED_PARAMETER(hPrevInstance);
    UNREFERENCED_PARAMETER(lpCmdLine);

    // TODO: Place code here.

    // Initialize global strings
    LoadStringW(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadStringW(hInstance, IDC_LISTIMAGEICONTEST, szWindowClass, MAX_LOADSTRING);
    MyRegisterClass(hInstance);

    // Perform application initialization:
    if (!InitInstance (hInstance, nCmdShow)) return FALSE;

    HACCEL hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_LISTIMAGEICONTEST));

    MSG msg;

    // Main message loop:
    while (GetMessage(&msg, nullptr, 0, 0))
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return (int) msg.wParam;
}



//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEXW wcex;

    wcex.cbSize = sizeof(WNDCLASSEX);

    wcex.style          = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = WndProc;
    wcex.cbClsExtra     = 0;
    wcex.cbWndExtra     = 0;
    wcex.hInstance      = hInstance;
    wcex.hIcon          = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_LISTIMAGEICONTEST));
    wcex.hCursor        = LoadCursor(nullptr, IDC_ARROW);
    wcex.hbrBackground  = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName   = MAKEINTRESOURCEW(IDC_LISTIMAGEICONTEST);
    wcex.lpszClassName  = szWindowClass;
    wcex.hIconSm        = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_SMALL));

    return RegisterClassExW(&wcex);
}

//
//   FUNCTION: InitInstance(HINSTANCE, int)
//
//   PURPOSE: Saves instance handle and creates main window
//
//   COMMENTS:
//
//        In this function, we save the instance handle in a global variable and
//        create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   hInst = hInstance; // Store instance handle in our global variable

   HWND hWnd = CreateWindowW(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, nullptr, nullptr, hInstance, nullptr);

   if (!hWnd)
   {
      return FALSE;
   }

   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);

   return TRUE;
}

//
//  FUNCTION: WndProc(HWND, UINT, WPARAM, LPARAM)
//
//  PURPOSE: Processes messages for the main window.
//
//  WM_COMMAND  - process the application menu
//  WM_PAINT    - Paint the main window
//  WM_DESTROY  - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_COMMAND:
        {
            int wmId = LOWORD(wParam);
            // Parse the menu selections:
            switch (wmId)
            {
            case IDM_ABOUT:
                DialogBox(hInst, MAKEINTRESOURCE(IDD_DIALOG1), hWnd, FoodDlgProc);
                break;
            case IDM_EXIT:
                DestroyWindow(hWnd);
                break;
            default:
                return DefWindowProc(hWnd, message, wParam, lParam);
            }
        }
        break;
    case WM_PAINT:
        {
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hWnd, &ps);
            // TODO: Add any drawing code that uses hdc here...
            EndPaint(hWnd, &ps);
        }
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    default:
        return DefWindowProc(hWnd, message, wParam, lParam);
    }
    return 0;
}


// Message handler for Square Meal dialog box. Click on Help -> ABout Box to activate this dialog.
// You must set the combo box properties to these for this to work.
//
// !!!!!   The combo box you create for this example uses the CBS_DROPDOWNLIST, CBS_OWNERDRAWFIXED, (optional)CBS_SORT, CBS_HASSTRINGS, WS_VSCROLL, and (optional) WS_TABSTOP styles. !!!!!!
//

INT_PTR CALLBACK FoodDlgProc(HWND hDlg, UINT message, WPARAM wParam,LPARAM lParam)
{
    UNREFERENCED_PARAMETER(lParam);
    TCHAR achTemp[256];
    HWND hwnd;

    switch (message)
    {
    case WM_INITDIALOG:

        // Call an application-defined function to load bitmap resources.
        if (!LoadIconBitmaps())
        {
            Beep(2000, 250);
            EndDialog(hDlg, -1);
            break;
        }

        // Initialize the food groups combo box and select the first item.
        InitGroupList(hDlg);
        SendDlgItemMessage(hDlg, IDCOMBO, CB_SETCURSEL, 0, 0);

        // Initialize the food list box and select the first item.
        InitFoodList(hDlg);
        SendDlgItemMessage(hDlg, IDLIST, LB_SETCURSEL, 0, 0);

        return (INT_PTR)TRUE;

    case WM_MEASUREITEM:
    {
        // Set the height of the items in the food groups combo box.
        LPMEASUREITEMSTRUCT lpmis = (LPMEASUREITEMSTRUCT)lParam;

        if (lpmis->itemHeight < CY_BITMAP + 2) lpmis->itemHeight = CY_BITMAP + 2; 

    }
    break;

    case WM_DRAWITEM:
    {
        COLORREF clrBackground;
        COLORREF clrForeground;
        TEXTMETRIC tm;
        int x;
        int y;
        HRESULT hr;
        size_t cch;

        LPDRAWITEMSTRUCT lpdis = (LPDRAWITEMSTRUCT)lParam;

        if (lpdis->itemID == -1) // Empty item)
            break;

        // Get the food icon from the item data.
        hbmIcon = (HBITMAP)lpdis->itemData;

        // The colors depend on whether the item is selected.
        clrForeground = SetTextColor(lpdis->hDC,
            GetSysColor(lpdis->itemState & ODS_SELECTED ?
                COLOR_HIGHLIGHTTEXT : COLOR_WINDOWTEXT));

        clrBackground = SetBkColor(lpdis->hDC,
            GetSysColor(lpdis->itemState & ODS_SELECTED ?
                COLOR_HIGHLIGHT : COLOR_WINDOW));

        // Calculate the vertical and horizontal position.
        GetTextMetrics(lpdis->hDC, &tm);
        y = (lpdis->rcItem.bottom + lpdis->rcItem.top - tm.tmHeight) / 2;
        x = LOWORD(GetDialogBaseUnits()) / 4;

        // Get and display the text for the list item.
        SendMessage(lpdis->hwndItem, CB_GETLBTEXT,
            lpdis->itemID, (LPARAM)achTemp);


        hr = StringCchLength(achTemp, 256, &cch);
        if (FAILED(hr))
        {
            // TODO: Write error handler.
        }


        ExtTextOut(lpdis->hDC, CX_BITMAP + 2 * x, y,
            ETO_CLIPPED | ETO_OPAQUE, &lpdis->rcItem,
            achTemp, (UINT)cch, NULL);

        // Restore the previous colors.
        SetTextColor(lpdis->hDC, clrForeground);
        SetBkColor(lpdis->hDC, clrBackground);

        //  Draw the food icon for the item. 
        HDC hdc = CreateCompatibleDC(lpdis->hDC);
        if (hdc == NULL)
            break;

        SelectObject(hdc, hbmMask);
        BitBlt(lpdis->hDC, x, lpdis->rcItem.top + 1,
            CX_BITMAP, CY_BITMAP, hdc, 0, 0, SRCAND);

        SelectObject(hdc, hbmIcon);
        BitBlt(lpdis->hDC, x, lpdis->rcItem.top + 1,
            CX_BITMAP, CY_BITMAP, hdc, 0, 0, SRCPAINT);

        DeleteDC(hdc);

        // If the item has the focus, draw the focus rectangle.
        if (lpdis->itemState & ODS_FOCUS) DrawFocusRect(lpdis->hDC, &lpdis->rcItem);


    }
    break;

    case WM_COMMAND:
        switch (LOWORD(wParam))
        {
        case IDCOMBO:
            if (HIWORD(wParam) == CBN_SELENDOK)
            {
                InitFoodList(hDlg);
                SendDlgItemMessage(hDlg, IDLIST,
                    LB_SETCURSEL, 0, 0);
            }
            break;

        case IDLIST:
            if (HIWORD(wParam) != LBN_DBLCLK)
                break;

            // For a double-click, process the OK case. 
        case IDOK:

            // Get the text for the selected list item. 
            hwnd = GetDlgItem(hDlg, IDLIST);

            // Here it is assumed the text can fit into achTemp.
            // If there is doubt, call LB_GETTEXTLENGTH first.
            SendMessage(hwnd, LB_GETTEXT,
                SendMessage(hwnd, LB_GETCURSEL, 0, 0),
                (LPARAM)achTemp);

            // TODO: Do something with the selected text.

            EndDialog(hDlg, 0);
            break;

        case IDCANCEL:
            hwnd = GetDlgItem(hDlg, IDCOMBO);
            if (SendMessage(hwnd, CB_GETDROPPEDSTATE, 0, 0))
                SendMessage(hwnd, CB_SHOWDROPDOWN, FALSE, 0);
            else EndDialog(hDlg, 0);
        }
        break;

    case WM_DESTROY:

        // Call the application-defined function to free the bitmap resources.
        DeleteIconBitmaps();
        break;
    }
    return (INT_PTR)FALSE;
}

// Loads string resources and adds them as items to the drop-down list of
//   the food groups combo box. The bitmap handle of each item&#39;s icon is
//   stored as item data for easy access when the item needs to be drawn.
// 
void InitGroupList(HWND hDlg)
{
    TCHAR achTemp[256];
    DWORD dwIndex;

    // Get the handle of the food groups combo box.
    HWND hwndGroupsBox = GetDlgItem(hDlg, IDCOMBO);

//LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR)); //originals were strings in editor
////dwIndex = SendMessage(hwndGroupsBox, CB_ADDSTRING, 0, (LPARAM)achTemp);
dwIndex = SendMessage(hwndGroupsBox, CB_ADDSTRING, 0, (LPARAM)_T("Bread"));
SendMessage(hwndGroupsBox, CB_SETITEMDATA, dwIndex, (LPARAM)hbm1);

//LoadString(hInst, IDS_DAIRY, achTemp, sizeof(achTemp) / sizeof(TCHAR));
dwIndex = SendMessage(hwndGroupsBox, CB_ADDSTRING, 0, (LPARAM)_T("Dairy"));
SendMessage(hwndGroupsBox, CB_SETITEMDATA, dwIndex, (LPARAM)hbm2);

//LoadString(hInst, IDS_FRUIT, achTemp, sizeof(achTemp) / sizeof(TCHAR));
dwIndex = SendMessage(hwndGroupsBox, CB_ADDSTRING, 0, (LPARAM)_T("Meat"));
SendMessage(hwndGroupsBox, CB_SETITEMDATA, dwIndex, (LPARAM)hbm3);

//LoadString(hInst, IDS_MEAT, achTemp, sizeof(achTemp) / sizeof(TCHAR));
dwIndex = SendMessage(hwndGroupsBox, CB_ADDSTRING, 0, (LPARAM)_T("Fruit"));
SendMessage(hwndGroupsBox, CB_SETITEMDATA, dwIndex, (LPARAM)hbm4);

    return;
}

// Fills the food list based on the selected item in the food groups combo box.
void InitFoodList(HWND hDlg)
{
    TCHAR achTemp[256];

    HWND hwndGroupsBox = GetDlgItem(hDlg, IDCOMBO);
    HWND hwndFoodList = GetDlgItem(hDlg, IDLIST);

    // Clear the list contents.
    SendMessage(hwndFoodList, LB_RESETCONTENT, 0, 0);

    // Find out which food group is selected.
    int idFoodGroup = SendMessage(hwndGroupsBox, CB_GETCURSEL, 0, 0);

    switch (idFoodGroup)
    {
    case ID_BREAD:
        LoadString(hInst, IDS_OATS, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        LoadString(hInst, IDS_WHEAT, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        LoadString(hInst, IDS_RYE, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);
        break;

    case ID_DAIRY:
        LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        break;

    case ID_FRUIT:
        LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        break;

    case ID_MEAT:
        LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        LoadString(hInst, IDS_BREAD, achTemp, sizeof(achTemp) / sizeof(TCHAR));
        SendMessage(hwndFoodList, LB_ADDSTRING, 0, (LPARAM)achTemp);

        break;

    default:
        break;
    }

    return;
}

// Loads the food icon bitmaps from the application resources.
//
BOOL LoadIconBitmaps(void)
{   
    hbmBread = (HBITMAP)LoadImageW(hInst, (wchar_t*) L"Blue.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE); //File has to be of format .bmp
    if (hbmBread != NULL) hbmDairy = (HBITMAP)LoadImageW(hInst, (wchar_t*) L"Green.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE); //File has to be of format .bmp
    if (hbmDairy != NULL) hbmMeat = (HBITMAP)LoadImageW(hInst, (wchar_t*)L"Red.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE); //File has to be of format .bmp
    if (hbmMeat != NULL) hbmFruit = (HBITMAP)LoadImageW(hInst, (wchar_t*)L"Black.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE); //File has to be of format .bmp
    if (hbmFruit != NULL) hbmMask = (HBITMAP)LoadImageW(hInst, (wchar_t*)L"Black.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE); //Needs to be a black mask to show other images.

/*
    // original code which still works, you need to put in bitmaps into the editor itself. eg IDB_Bread, IDB_DAIRY, are 48x48 bitmaps in my editor by default.
    hbmBread = LoadBitmap(hInst, MAKEINTRESOURCE(IDB_BREAD));
    if (hbmBread != NULL) hbmDairy = LoadBitmap(hInst, MAKEINTRESOURCE(IDB_DAIRY));
    if (hbmDairy != NULL) hbmMeat = LoadBitmap(hInst, MAKEINTRESOURCE(IDB_Green));
    */

    //if (hbmMeat != NULL) hbmFruit = LoadBitmap(hInst, MAKEINTRESOURCE(IDB_BREAD)); //Bitmap defined in the editor(resource.h) which calls a Black.bmp file. See VS Bitmap editor.
    //if (hbmFruit != NULL) hbmMask = LoadBitmap(hInst, MAKEINTRESOURCE(IDB_BREAD));

    if (hbmMask != NULL)
        return TRUE;


    return FALSE;
}

// Frees the icon bitmps.
//
void DeleteIconBitmaps(void)
{
    FreeResource(reinterpret_cast<HGLOBAL>(hbmBread));
    FreeResource(reinterpret_cast<HGLOBAL>(hbmDairy));
    FreeResource(reinterpret_cast<HGLOBAL>(hbmMeat));
    FreeResource(reinterpret_cast<HGLOBAL>(hbmFruit));
    FreeResource(reinterpret_cast<HGLOBAL>(hbmMask));
}