CTreeCtrl：如何清除所选项目的焦点答案

【问题标题】：CTreeCtrl: How to clear the focus of selected itemCTreeCtrl：如何清除所选项目的焦点
【发布时间】：2015-07-02 06:06:27
【问题描述】：

我是 MFC 新手，我想复制准确的 Ctrl+Page Down 和 Ctrl+Page Up 行为对常规 Page Down/Page Up 键没有任何支持键 (Ctrl/Shift)。我一直在尝试清除在点击 Page Up 和 Page Down 键时自动选择的项目的焦点。

我已尝试使用此代码，但无法正常工作：

case VK_NEXT:   // pagedown
case VK_PRIOR:  // pageup
    lhItem = GetFocusedItem();
    if (IsSelected(lhItem))
    {
        CTreeCtrl::SetItemState(lhItem, 0, TVIS_SELECTED);
    }
    break;

谁能帮我解决这个问题

【问题讨论】：

今后请尽量减少对格式的草率，并阅读Markdown help。
你把“这段代码”放在哪里了？
我将代码保存在 void CiTreeCtrl::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags) {} 函数中

标签： visual-c++ visual-studio-2013 mfc

【解决方案1】：

代码需要写在 OnSelChanging & OnSelChanged 事件处理函数中

void CTreeCtrl::OnSelchanging(NMHDR *pNMHDR, LRESULT *pResult)
{
    HTREEITEM hNew = pNMTreeView->itemNew.hItem;
    HTREEITEM hOld = pNMTreeView->itemOld.hItem;

    m_bOldItemSelected = hOld && (CTreeCtrl::GetItemState(hOld, UINT(TVIS_SELECTED)) & TVIS_SELECTED);

if (GetSelectedCount() > 1)
{
    if (m_bPgUpState || m_bPgDownState)
    {
        //Check the state of New Item
        if ((pNMTreeView->itemNew.state & TVIS_SELECTED))
        {
            // If the item is selected, so make sure OnSelchanged()
            // will "select" it !
            m_bNewItemSelected = TRUE;
        }
        else if (!(pNMTreeView->itemNew.state & TVIS_SELECTED))
        {
            // The New item is not selected, so make sure OnSelchanged()
            // will not "re-select" it !
            m_bNewItemSelected = FALSE;
            CTreeCtrl::SetItemState(hNew, UINT(~TVIS_SELECTED), UINT(TVIS_SELECTED));
        }
    }
}

void TreeCtrl::OnSelchanged(NMHDR* pNMHDR, LRESULT* pResult)
{
    NM_TREEVIEW* pNMTreeView = (NM_TREEVIEW*)pNMHDR;

    HTREEITEM itemNew = pNMTreeView->itemNew.hItem;
    HTREEITEM itemOld = pNMTreeView->itemOld.hItem;
if ((m_bPgUpState || m_bPgDownState) && (GetSelectedCount() > 1)
    && (pNMTreeView->itemOld.hItem != NULL || pNMTreeView->itemNew.hItem != NULL))
{
    // It had the focus so Keep selection at old item
    if (itemOld && m_bOldItemSelected)
    {
        CTreeCtrl::SetItemState(itemOld, UINT(TVIS_SELECTED), UINT(TVIS_SELECTED));
        m_bOldItemSelected = FALSE;
    }
    else
    {
        // Do-not select the item if it is not selected
        CTreeCtrl::SetItemState(itemOld, UINT(~TVIS_SELECTED), UINT(TVIS_SELECTED));
    }

}

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【讨论】：