vc海量数据树控件使用总结

vc海量数据树控件使用总结当有海量数据时，不能一次性初始化树控件，否则速度极慢，这里采用：用户每点击一个节点，就初始化这个节点包含的子节点的方法。

1.初始化第一层节点：先添加一个总的父节点

HTREEITEM root0=m_Tree.InsertItem(_T("tianyu"),0,1,TVI_ROOT,TVI_LAST);

2.再添加没有父节点的节点，即第一层节点：

{ CADODatabase *lpDB=new CADODatabase; lpDB->Open(_T("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C://Documents and Settings//fangxing//桌面//KEY.mdb"),_T("Admin"),_T("")); if (!lpDB->IsOpen()) { delete lpDB; AfxMessageBox("无法连接数据库"); return FALSE; } CADORecordset* rd=new CADORecordset(lpDB); CString csTemp; csTemp="select * from K_DEPT_DEPARTMENT"; HTREEITEM sub_son0; int iSuperID=-2; int iDeptID =-1; rd->Open(csTemp,1); do{ if(!rd->IsEOF()) { rd->GetFieldValue("DEPTNAME",csTemp); rd->GetFieldValue("superior_deptid",iSuperID); rd->GetFieldValue("DEPTID",iDeptID); if (iSuperID == -1 )//说明没有上级部门 { sub_son0=m_Tree.InsertItem(csTemp,0,1,root0,TVI_LAST); //m_Tree.SetItemState() CADORecordset* rd_son=new CADORecordset(lpDB); CString csSonTemp; csSonTemp.Format("select * from K_DEPT_DEPARTMENT where superior_deptid = %d",iDeptID); rd_son->Open(csSonTemp,1); if (!rd_son->IsEOF())//这里只是查找第一层节点是否含子节点，含的话就手动添加一个“+”号。 { CTreeCtrl *tree=(CTreeCtrl*)GetDlgItem(IDC_TREE1); TVITEM item; memset(&item,0,sizeof(TVITEM)); item.hItem=sub_son0; tree->GetItem(&item); item.mask= TVIF_CHILDREN; item.cChildren=1; tree->SetItem(&item); } rd_son->Close(); delete rd_son; } rd->MoveNext(); } } while (!rd->IsEOF()); //HTREEITEM sub_sub_son0=m_Tree.InsertItem("son_son",0,1,sub_son0,TVI_LAST); rd->Close(); delete rd; lpDB->Close(); delete lpDB; } 

 

3.当用户展开"+"号时

//点击加号 void CProcessSetDlg::OnTvnItemexpandingTree1(NMHDR *pNMHDR, LRESULT *pResult) { LPNMTREEVIEW pNMTreeView = reinterpret_cast(pNMHDR); // TODO: 在此添加控件通知处理程序代码 HTREEITEM item = pNMTreeView->itemNew.hItem; HTREEITEM hTest = m_Tree.GetChildItem(item); CString csTemp = m_Tree.GetItemText(item); UINT u =m_Tree.GetItemState(item,TVIS_EXPANDEDONCE); //if (hTest == NULL) if(u ==0 )//说明一次也没被展开过 { m_Tree.SelectItem(item);//触发树控件的项选择事件 } *pResult = 0; }  

4.当用户选择一个旁边有“+”号的项时，此时初始化这个项的子节点

void CProcessSetDlg::OnTvnSelchangedTree1(NMHDR *pNMHDR, LRESULT *pResult) { LPNMTREEVIEW pNMTreeView = reinterpret_cast(pNMHDR); // TODO: 在此添加控件通知处理程序代码 HTREEITEM hItem = m_Tree.GetSelectedItem(); HTREEITEM hTest; { CADODatabase *lpDB=new CADODatabase; lpDB->Open(_T("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C://Documents and Settings//fangxing//桌面//KEY.mdb"),_T("Admin"),_T("")); if (!lpDB->IsOpen()) { delete lpDB; AfxMessageBox("无法连接数据库"); // return FALSE; } CString csCurSel =m_Tree.GetItemText(hItem); CADORecordset* rd_son=new CADORecordset(lpDB); CString csSonTemp; csSonTemp.Format("select * from K_DEPT_DEPARTMENT where DEPTNAME = '%s'",csCurSel); rd_son->Open(csSonTemp,1); int iDeptID = -1; if (!rd_son->IsEOF()) { rd_son->GetFieldValue("DEPTID",iDeptID); } rd_son->Close(); delete rd_son; if (iDeptID ==-1) { goto init; } hTest = m_Tree.GetChildItem(hItem); // if (!m_Tree.ItemHasChildren(hItem)) if(hTest == NULL) { CADORecordset* rd_son1=new CADORecordset(lpDB); csSonTemp.Format("select * from K_DEPT_DEPARTMENT where superior_deptid = %d",iDeptID); rd_son1->Open(csSonTemp,1); do { if (!rd_son1->IsEOF()) { CString csSonName ; rd_son1->GetFieldValue("DEPTNAME",csSonName); m_Tree.InsertItem(csSonName,0,1,hItem,TVI_LAST); rd_son1->MoveNext(); } } while (!rd_son1->IsEOF()); rd_son1->Close(); delete rd_son1; } } init: // if (!m_Tree.ItemHasChildren(hItem)) //if(hTest == NULL) { m_List.DeleteAllItems(); /*根据所选部门的名称，查数据库，找出这个部门的部门策略名，之后插到listctl中*/ CString csCurSel =m_Tree.GetItemText(hItem); CADODatabase *lpDB=new CADODatabase; lpDB->Open(_T("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C://Documents and Settings//fangxing//桌面//KEY.mdb"),_T("Admin"),_T("")); if (!lpDB->IsOpen()) { delete lpDB; AfxMessageBox("无法连接数据库"); // return FALSE; } CADORecordset* rd=new CADORecordset(lpDB); CString csTemp; csTemp="select NETPOLICYNAME from K_NET_CONTROLPOLICY , K_DEPT_DEPARTMENT where DEPT = DEPTID and DEPTNAME = '"+csCurSel+"'"; rd->Open(csTemp,1); do { if (!rd->IsEOF()) { rd->GetFieldValue("NETPOLICYNAME",csTemp); m_List.InsertItem(0,csTemp); rd->MoveNext(); } } while (!rd->IsEOF()); rd->Close(); delete rd; lpDB->Close(); delete lpDB; //m_List.InsertItem(0,m_Tree.GetItemText(hItem)); } *pResult = 0; }