繪制CTreeCtrl的+/-展開(kāi)按鈕的代碼.
void DrawExpandButton( HDC hdc, LONG x, LONG y, BOOL bExpand, BOOL bFill )
{
const int PROPTREEITEM_EXPANDBOX = 9; // 按鈕大小
const int PROPTREEITEM_EXPANDBOXHALF = (PROPTREEITEM_EXPANDBOX / 2);
HPEN hPen;
HPEN oPen;
HBRUSH oBrush;
hPen = CreatePen(PS_SOLID, 1, GetSysColor(COLOR_BTNSHADOW));
oPen = (HPEN)SelectObject(hdc, hPen);
oBrush = (HBRUSH)SelectObject(hdc, GetStockObject(bFill ? WHITE_BRUSH : NULL_BRUSH));
Rectangle(hdc, x, y, x + PROPTREEITEM_EXPANDBOX, y + PROPTREEITEM_EXPANDBOX);
SelectObject(hdc, GetStockObject(BLACK_PEN));
if (!bExpand)
{
MoveToEx(hdc, x + PROPTREEITEM_EXPANDBOXHALF, y + 2, NULL);
LineTo(hdc, x + PROPTREEITEM_EXPANDBOXHALF, y + PROPTREEITEM_EXPANDBOX - 2);
}
MoveToEx(hdc, x + 2, y + PROPTREEITEM_EXPANDBOXHALF, NULL);
LineTo(hdc, x + PROPTREEITEM_EXPANDBOX - 2, y + PROPTREEITEM_EXPANDBOXHALF);
SelectObject(hdc, oPen);
SelectObject(hdc, oBrush);
DeleteObject(hPen);
}