Unsigned integer that specifies the control type. It can be one of the following values.
ValueDescription
ODT_BUTTON
Owner-drawn button
ODT_LISTVIEW
Owner-draw list view control
ODT_MENU
Owner-drawn menu
ODT_TAB
Tab control
CtlID
Unsigned integer that specifies the identifier of the combo box, list box, or button. This member is not used for a menu.
itemID
Unsigned integer that specifies the menu item identifier for a menu item or the index of the item in a list box or combo box. For an empty list box or combo box, this member can be –1. This value allows the application to draw only the focus rectangle at the coordinates specified by the rcItem member, even though the control contains no items. This focus rectangle indicates to the user whether the list box or combo box has the focus. The value of the itemAction member determines whether the rectangle is to be drawn as though the list box or combo box has the focus.
itemAction
Unsigned integer that specifies the drawing action required. This member can have one or more of the following values.
ValueDescription
ODA_DRAWENTIRE
The entire control needs to be drawn.
ODA_FOCUS
The control has lost or gained the keyboard focus. You should check the itemState member to determine whether the control has the focus.
ODA_SELECT
The selection status has changed. You should check the itemState member to determine the new selection state.
itemState
Unsigned integer that specifies the visual state of the item after the current drawing action takes place. It can be a combination of the following values.
ValueDescription
ODS_CHECKED
The menu item is to be checked. Use this value only in a menu.
ODS_COMBOBOXEDIT
The drawing takes place in the edit control of an owner-drawn combo box.
ODS_DEFAULT
The item is the default item.
ODS_DISABLED
The item is to be drawn as disabled.
ODS_FOCUS
The item has the keyboard focus.
ODS_GRAYED
The item is to be grayed. Use this value only in a menu.
ODS_SELECTED
The status of the menu item is selected.
hwndItem
Handle to the control for combo boxes, list boxes, buttons, and static controls. For menus, this member is a handle to the menu containing the item.
hDC
Handle to a device context. You must use this device context when performing drawing operations on the control.
rcItem
RECT structure that specifies a rectangle that defines the boundaries of the control to be drawn. This rectangle is in the device context that you specified with the hDC member. The OS automatically clips anything that the owner window draws in the device context for combo boxes, list boxes, and buttons, but does not clip menu items. When drawing menu items, the owner window must not draw outside the boundaries of the rectangle defined by the rcItem member.
itemData
Pointer to an unsigned long that specifies the application-defined 32-bit value associated with the menu item. For a control, this member specifies the value last assigned to the list box or combo box by the LB_SETITEMDATA or CB_SETITEMDATA message. If the list box or combo box has the LB_HASSTRINGS or CB_HASSTRINGS style, this value is initially zero. Otherwise, this value is initially the value passed to the list box or combo box in the lParam parameter of one of the following messages:
CB_ADDSTRING
CB_INSERTSTRING
LB_ADDSTRING
LB_INSERTSTRING
If CtlType is ODT_BUTTON, itemData is zero.
文檔中有這句話： “The owner window of the owner-drawn control or menu item receives a pointer to this structure as the lParam parameter of the WM_DRAWITEM message.” 即lParam參數中包含指向一個DRAWITEMSTRUCT結構的指針。 另外wParam參數用來指定發送WM_DRAWITEM消息的控件標識符。如果該消息是由菜單發送的，則該參數為零。
2.示例(修改自codeproject)
在創建主窗口獲得主窗口句柄hWnd后創建按鈕： hLevelUpButton = CreateWindow(_T("button"), NULL, WS_CHILD | WS_VISIBLE | BS_OWNERDRAW, 0, 0, 32, 32, hWnd, (HMENU) IDC_LEVELUPBUTTON, g_hInst, NULL);
if (NULL == hLevelUpButton) { MessageBox(hWnd, L"Create up button fails", L"Message", MB_OK);
} hLevelDnButton = CreateWindow(_T("button"), NULL, WS_CHILD | WS_VISIBLE | BS_OWNERDRAW, 32, 0, 32, 32, hWnd, (HMENU) IDC_LEVELDNBUTTON, g_hInst, NULL);
if (NULL == hLevelDnButton) { MessageBox(hWnd, L"Create down button fails", L"Message", MB_OK);
} 在主窗口消息處理里定義結構體： DRAWITEMSTRUCT* pdis; 添加消息處理： case WM_DRAWITEM: pdis = (DRAWITEMSTRUCT*) lParam; // (winuser.h) Maybe you also want to account for pdis->CtlType (ODT_MENU, ODT_LISTBOX,ODT_COMBOBOX, ODT_BUTTON, ODT_STATIC) switch(pdis->CtlID) { case IDC_LEVELUPBUTTON: // Fall through (you would use a "break" otherwise): case IDC_LEVELDNBUTTON: result = OwnerDrawButton(pdis, g_hInst); if (FALSE == result) { MessageBox(hWnd, L"OwnerDrawButton return fasle", L"Message", MB_OK); return(FALSE); } break; // Other case labels if any... default: break; } //如果處理該消息，則必須返回TRUE return(TRUE);
OwnerDrawButton函數的定義如下：
BOOL OwnerDrawButton(DRAWITEMSTRUCT* pdis, HINSTANCE hInstance)
{ static RECT rect; static int iCount = 0; // Icon handles: static HICON hCurrIcon, hUpIconI, hDnIconI, hUpIconA, hDnIconA; // Use copy of rectangle: rect = pdis->rcItem; //只載入一次Icon if (iCount < 1) { // LoadIcon only loads once, but LoadImage does not, // so in case you call the latter, use a static counter: iCount++; // Inactive buttons: hUpIconI = (HICON) LoadIcon(hInstance, MAKEINTRESOURCE(ID_UP_ICONI)); if (!hUpIconI) { MessageBox(NULL, L"Loading ID_UP_ICONI icon fails", L"Message", MB_OK); } hDnIconI = (HICON) LoadIcon(hInstance, MAKEINTRESOURCE(ID_DN_ICONI)); if (!hDnIconI) { MessageBox(NULL, L"Loading ID_DN_ICONI icon fails", L"Message", MB_OK); } // Active buttons: hUpIconA = (HICON) LoadIcon(hInstance, MAKEINTRESOURCE(ID_UP_ICONA)); if (!hUpIconA) { MessageBox(NULL, L"Loading ID_UP_ICONA icon fails", L"Message", MB_OK); } hDnIconA = (HICON) LoadIcon(hInstance, MAKEINTRESOURCE(ID_DN_ICONA)); if (!hDnIconA) { MessageBox(NULL, L"Loading ID_DN_ICONA icon fails", L"Message", MB_OK); } } // If the control's id is that of the "Up" button: if (IDC_LEVELUPBUTTON == pdis->CtlID) { // If the button is selected, display the // "active" icon, else the "inactive" icon: if (pdis->itemState & ODS_SELECTED) hCurrIcon = hUpIconA; else hCurrIcon = hUpIconI; } // If the control's id is that of the "Down" button: if (IDC_LEVELDNBUTTON == pdis->CtlID) { // If the button is selected, display the // "active" icon, else the "inactive" icon: if (pdis->itemState & ODS_SELECTED) hCurrIcon = hDnIconA; else hCurrIcon = hDnIconI; } // Center the icon inside the control's rectangle: if (!DrawIconEx( pdis->hDC, (int) 0.5 * (rect.right - rect.left - ICON_WIDTH), (int) 0.5 * (rect.bottom - rect.top - ICON_HEIGHT), (HICON) hCurrIcon,//根據上面指定的Icon繪制 ICON_WIDTH, ICON_HEIGHT, 0, NULL, DI_NORMAL )) { MessageBox(NULL, L"Drawing icon fails", L"Message", MB_OK); } return TRUE;
}
附件項目的環境是： Win32/Windows Mobile 6 Professional(CHS)/Visual Studio 2008(CHS)? /Files/wangkewei/OwnerDrawButton.rar
