当代码在没有真正更改的情况下意外地开始工作时

When code accidently starts to work without a real change

本文关键字：意外 情况下 开始 工作 代码      更新时间：2023-10-16

我以前遇到过类似的情况，当我的代码不能正常工作时，为了解决问题，我做了一些更改，而不是注释这些更改，然后它就解决了问题。突然间，只是在文件的某个地方进行了一次"编辑"，解决了这个问题，但代码并没有真正的变化。我又遇到了类似的问题，我只是想知道这是怎么发生的?

void CDlgResizeHelper::Init(HWND hparent) 
{
    m_hParent = hparent;
    m_CtrlsList.clear();

    if (::IsWindow(m_hParent)) 
    {
        ::GetWindowRect(m_hParent, m_OrigParentSize);
        // get all child windows and store their original sizes and positions
        HWND hCtrl = ::GetTopWindow(m_hParent);
        while (hCtrl) 
        {
            CtrlSize cs;
            cs.hctrl = hCtrl;
            ::GetWindowRect(hCtrl, cs.orig_size);
            ::ScreenToClient(m_hParent, &cs.orig_size.TopLeft());
            ::ScreenToClient(m_hParent, &cs.orig_size.BottomRight());

        //  CString msg;
        //  msg.Format("Old Size: %d        %d      %d      %drn", cs.orig_size.left, cs.orig_size.top, cs.orig_size.right, cs.orig_size.bottom );
        //  TRACE( msg );
            m_CtrlsList.push_back(cs);
            hCtrl = ::GetNextWindow(hCtrl, GW_HWNDNEXT);
        }
    }
}
这个类/函数根据对话框的大小调整控件的大小。它在调试版本中工作，但相同的代码在发布版本中不起作用(=正确调整大小)。我做了一些修改，并在上面的TRACE函数循环中添加了三行代码。它在发布版本中也开始正常工作。然后我注释了这些行，它仍然可以在发布版本中工作。我删除了它们，它在发布版本中不再工作了。我必须有这些行刚刚注释现在发布构建做正确的事情。这怎么能站得住脚呢?什么可能真正导致这个"编辑"的文件，这是真的没有改变，在实际的代码解决问题?

我还想补充说，我已经尝试过"编辑"或注释新代码，否则在文件中不一定能解决问题。我只需要在上面的函数中有注释的代码来修复它。

Update这是完整的类。我必须说这门课在网上是免费的，我不是原作者。

  • Init从需要调整大小的对话框的OnInitDialog调用。它只是存储所有控件的坐标。

  • OnSize()实际上会调整大小。

    CDlgResizeHelper: CDlgResizeHelper ()｛}

    void CDlgResizeHelper::Init(HWND hparent)｛m_hParent = hparent;

    m_CtrlsList.clear ();
    if (::IsWindow(m_hParent)) 
{
    ::GetWindowRect(m_hParent, m_OrigParentSize);
    // get all child windows and store their original sizes and positions
    HWND hCtrl = ::GetTopWindow(m_hParent);
    while (hCtrl) 
    {
        CtrlSize cs;
        cs.hctrl = hCtrl;
        ::GetWindowRect(hCtrl, cs.orig_size);
        ::ScreenToClient(m_hParent, &cs.orig_size.TopLeft());
        ::ScreenToClient(m_hParent, &cs.orig_size.BottomRight());

        CString msg;
        msg.Format("Old Size: %d        %d      %d      %drn", cs.orig_size.left, cs.orig_size.top, cs.orig_size.right, cs.orig_size.bottom );
        Sleep( 50 );
        m_CtrlsList.push_back(cs);
        hCtrl = ::GetNextWindow(hCtrl, GW_HWNDNEXT);
    }
}

    }

    void CDlgResizeHelper::Remove(HWND HWND)｛CtrlList:: iterator, 

    for (it = m_CtrlsList.begin(); it != m_CtrlsList.end(); ++it) 
{
    if (it->hctrl == hwnd)
    {
        m_CtrlsList.erase(it);
        return;
    }
}

    }

    void CDlgResizeHelper::Update(HWND HWND)｛if (m_hParent &&hwnd)｛CtrlList:: iterator, 

        for (it = m_CtrlsList.begin(); it != m_CtrlsList.end(); ++it) 
    {
        if (it->hctrl == hwnd)
        {
            ::GetWindowRect(hwnd, &(it->orig_size));
            ::ScreenToClient(m_hParent, &(it->orig_size.TopLeft()));
            ::ScreenToClient(m_hParent, &(it->orig_size.BottomRight()));
        }
    }

}

}

void CDlgResizeHelper::Add(HWND HWND)｛if (m_hParent &&hwnd)｛CtrlSize cs;cs。

    ::GetWindowRect(hwnd, cs.orig_size);
    ::ScreenToClient(m_hParent, &cs.orig_size.TopLeft());
    ::ScreenToClient(m_hParent, &cs.orig_size.BottomRight());
    m_CtrlsList.push_back(cs);
}

}

空白CDlgResizeHelper: OnSize ()｛如果(::IsWindow (m_hParent))｛绘图用的矩形类currparentsize;:: GetWindowRect (m_hParent currparentsize); 

    double xratio = ((double) currparentsize.Width()) / m_OrigParentSize.Width();
    double yratio = ((double) currparentsize.Height()) / m_OrigParentSize.Height();
    HDWP hdwp; 
    hdwp = BeginDeferWindowPos((int)m_CtrlsList.size()); 
    // resize child windows according to their fix attributes
    CtrlList::const_iterator it;
    for (it = m_CtrlsList.begin(); it != m_CtrlsList.end(); ++it) 
    {
        CRect currctrlsize;
        HorizFix horiz_fix = it->horiz_fix;
        VertFix vert_fix = it->vert_fix;
        if (horiz_fix & LEFT) 
            currctrlsize.left = it->orig_size.left;
        else 
            currctrlsize.left = (LONG)( ((horiz_fix & WIDTH) && (horiz_fix & RIGHT)) ? (it->orig_size.left + currparentsize.Width() - m_OrigParentSize.Width()) : (it->orig_size.left * xratio));
        if (horiz_fix & RIGHT) 
            currctrlsize.right = it->orig_size.right + currparentsize.Width() - m_OrigParentSize.Width();
        else 
            currctrlsize.right = (LONG)((horiz_fix & WIDTH) ? (currctrlsize.left + it->orig_size.Width()) : (it->orig_size.right * xratio));
        if (vert_fix & TOP) 
            currctrlsize.top = it->orig_size.top;
        else 
            currctrlsize.top = (LONG)(((vert_fix & HEIGHT) && (vert_fix & BOTTOM)) ? (it->orig_size.top + currparentsize.Height() - m_OrigParentSize.Height()) : (it->orig_size.top * yratio));
        if (vert_fix & BOTTOM) 
            currctrlsize.bottom = it->orig_size.bottom + currparentsize.Height() - m_OrigParentSize.Height();
        else 
            currctrlsize.bottom = (LONG)((vert_fix & HEIGHT) ? (currctrlsize.top + it->orig_size.Height()) : (it->orig_size.bottom * yratio));
        UINT flags = SWP_NOZORDER;
        if (! it->resize)
            flags |= SWP_NOSIZE;

        hdwp = ::DeferWindowPos(hdwp, it->hctrl, NULL, currctrlsize.left, currctrlsize.top, (it->resize)? currctrlsize.Width() : 0, (it->resize)? currctrlsize.Height() : 0, flags); 
        if (hdwp == NULL)
            return;
    } //end for (it = m_CtrlsList.begin(); it != m_CtrlsList.end(); ++it) 
    EndDeferWindowPos(hdwp);
} //end if (::IsWindow(m_hParent))

}

BOOL CDlgResizeHelper::Fix(HWND a_hCtrl, HorizFix a_hFix, VertFix a_vFix, BOOL resize/= true/)｛CtrlList:: iterator, 

for (it = m_CtrlsList.begin(); it != m_CtrlsList.end(); ++it) 
{
    if (it->hctrl == a_hCtrl) 
    {
        it->horiz_fix = a_hFix;
        it->vert_fix = a_vFix;
        it->resize = resize;
        return TRUE;
    }
}
return FALSE;

}

BOOL CDlgResizeHelper::Fix(int a_itemId, HorizFix a_hFix, VertFix a_vFix, BOOL resize/= true/)｛return Fix(::GetDlgItem(m_hParent, a_itemId)， a_hFix, a_vFix, resize);}

BOOL CDlgResizeHelper::Fix(horizonfix a_hFix, VertFix a_vFix, BOOL resize/= true/)｛CtrlList:: iterator, 

for(it = m_CtrlsList.begin(); it!=m_CtrlsList.end(); ++it) 
{
    it->horiz_fix = a_hFix;
    it->vert_fix = a_vFix;
    it->resize = resize;
}
return TRUE;

}

UINT CDlgResizeHelper::Fix(LPCTSTR a_pszClassName, HorizFix a_hFix, VertFix a_vFix, bool resize/= true/)｛char cn_buf [200],
Memset (cn_buf, 0, 200);

UINT cnt = 0;
CtrlList::iterator it;
for (it = m_CtrlsList.begin(); it!= m_CtrlsList.end(); ++it) 
{
    ::GetClassName(it->hctrl, cn_buf, sizeof(cn_buf));
    if (strcmp(cn_buf, a_pszClassName) == 0) 
    {
        cnt++;
        it->horiz_fix = a_hFix;
        it->vert_fix = a_vFix;
        it->resize = resize;
    }
}
return cnt;

}

这听起来像是在某个地方使用了未初始化的变量。它可以根据构建模式获得不同的值，而且碰巧在调试时它被分配了一些无害的值。

尝试运行CppCheck应用程序对您的代码。反正也没关系。

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