CTreeCtrl：如何清除所选项目的焦点

Posted 2023-02-16

【中文标题】CTreeCtrl：如何清除所选项目的焦点

【英文标题】：CTreeCtrl: How to clear the focus of selected item

【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

【参考方案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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