Duilib实现 Windows资源管理器前进后退原理

一、用两个vector保存路径

  vector<wstring> vctBacks;//保存后退路径的集合

  vector<wstring> vctForwards//保存前进路径集合

  CButtonUI*  pBackbtn;//后退按钮

  CButtonUI* pForwardbtn;//前进按钮

1.程序初始化时，两个按钮不可用状态

2.当点击一系列目录后，后退集合把这些路径保存，后退按钮设为可用状态

3.当点击后退按钮，把vctBacks最后一个元素取出来 wstring temp = vctBacks.back()，放进前进集合里 vctForwards.push_back(temp),然后后退集合删除掉最后一个 vctBacks.pop_back()

4.再点击前进按钮，把vctForwards最后一个元素取出来 wstring temp = vctForwards.back(),，放进前进集合里 vctBacks.push_back(temp),然后后退集合删除掉最后一个 vctForwards.pop_back()

5.若前进集合还有一个元素时，取出元素push到后退集合里。然后把前进按钮设为不可用；若后退集合还有一个元素时，取出元素push到前几集合里，然后把后退按钮设为不可用

void OnClickBtnForward()
{
    if (m_vctForwards.size() > 0)
    {
        if (m_vctForwards.size() == 1)
        {
            wstring wstr = m_vctForwards.back();
            CListLabelElementUI* pElement = (CListLabelElementUI*)(m_pLeftTree->FindSubControl(wstr.c_str()));

            if (pElement)
            {
                pElement->Select();
            }
            
            m_vctBacks.push_back(wstr);
            m_vctForwards.pop_back();

            if (m_vctForwards.empty())//在此判断有点多余
            {
                m_pForwardbtn->SetEnabled(false);
            }

            if (!m_vctBacks.empty())
            {
                m_pBackbtn->SetEnabled(true);
            }
            
            m_pPath->SetText(wstr.c_str());
            m_pFileList->RemoveAll();
            InitFileList(wstr.c_str());
            return;
        }
        else
        {
            wstring  temp = m_vctForwards.back();
            m_vctBacks.push_back(temp);
            m_vctForwards.pop_back();
            temp = m_vctBacks.back();

            CListLabelElementUI* pElement = (CListLabelElementUI*)(m_pLeftTree->FindSubControl(temp.c_str()));
            if (pElement != NULL)
            {
                pElement->Select();
            }

            if (!m_vctBacks.empty())
            {
                m_pBackbtn->SetEnabled(true);
            }

            m_pFileList->RemoveAll();
            InitFileList(temp.c_str());
            m_pPath->SetText(temp.c_str());
        }
    }
}

void OnClickBtnBack()
{
    if (m_vctBacks.size() > 0)
    {

        if (m_vctBacks.size() == 1)
        {
            wstring wstr = m_vctBacks.back();
            CListLabelElementUI* pElement = (CListLabelElementUI*)(m_pLeftTree->FindSubControl(wstr.c_str()));

            if (pElement)
            {
                pElement->Select();
            }
            m_vctForwards.push_back(wstr);
            m_vctBacks.pop_back();
            m_pPath->SetText(_T(""));
            m_pBackbtn->SetEnabled(false);
            m_pFileList->RemoveAll();
            return;
        }
        else
        {
            wstring temp = m_vctBacks.back();
            m_vctForwards.push_back(temp);//只要执行这行代码,前进按钮就可用
            if (!m_vctForwards.empty())
            {
                m_pForwardbtn->SetEnabled(true);
            }
            m_vctBacks.pop_back();
            temp = m_vctBacks.back();

            CListLabelElementUI* pElement = (CListLabelElementUI*)(m_pLeftTree->FindSubControl(temp.c_str()));

            if (pElement != NULL)
            {
                pElement->Select();
            }
            m_pFileList->RemoveAll();
            InitFileList(temp.c_str());
            m_pPath->SetText(temp.c_str());
        }    
    }
}