c++ - BitBlt 内存泄漏

Question

我正在使用 BitBlt 在我的按钮上显示位图。对于大多数情况，它很好，但是存在内存泄漏，导致程序在一段时间后崩溃。我做错了什么？

int Springboard::DrawBasicButtons(DRAWITEMSTRUCT* pdis, HINSTANCE hInstance){
    RECT rect;
    static HBITMAP hCurrIcon, hIconoff, hIconon;
    rect = pdis->rcItem;

    HFONT font = CreateFont(13, 0, 0, 0, 300, FALSE, FALSE, FALSE, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY, DEFAULT_PITCH, L"Arial");
    TCHAR Txtstr[MAX_PATH];
    BOOL isText = FALSE;
    int textsize;

    if (IDC_HOLD == pdis->CtlID) {
        hIconoff = (HBITMAP) LoadBitmap(hInstance, MAKEINTRESOURCE(BASIC_HOLDOFF));
        hIconon = (HBITMAP) LoadBitmap(hInstance, MAKEINTRESOURCE(BASIC_HOLDON));
        _tcscpy( Txtstr, _T("Hold      "));
        isText = TRUE;
        if (pdis->itemState & ODS_SELECTED) hCurrIcon = hIconon;
        else hCurrIcon = hIconoff;
    }

    HDC hdc = CreateCompatibleDC(pdis->hDC);
    SelectObject(hdc, hCurrIcon);

    BitBlt(pdis->hDC,0, 0,ICON_WIDTH,ICON_HEIGHT, hdc, 0, 0, SRCCOPY);

    if(isText == TRUE){
        textsize = _tcslen(Txtstr);
        SetTextColor(pdis->hDC, RGB(230,230,230));
        HFONT hFontOld = (HFONT) SelectObject(pdis->hDC, font);
        DrawText(pdis->hDC, Txtstr, textsize, &pdis->rcItem, DT_SINGLELINE | DT_VCENTER | DT_RIGHT);
        SelectObject( pdis->hDC, hFontOld );
    }

    DeleteDC(hdc);
    DeleteBitmap(hCurrIcon);
    DeleteBitmap(hIconoff);
    DeleteBitmap(hIconon);
    font = NULL;

    return(RET_OK);
}

Answer 1

在调用 DeleteDC() 之前，您需要将旧对象选回 HDC。

此外，您似乎没有清理 CreateFont() 返回的 HFONT。