WinForm TreeView的应用以及和ListView的关联

加载树的方法，我换成了另一种，先前那一种用了递归的思想，
每次程序一运行，那么就会加载数据库里面的数据到树视图上，
这样既浪费时间又浪费空间，后来经过Crennah提示以及他给的参考代码，
我换成了另外一种形式的代码，也就是当点击树节点的时候才加载它下面的子节点。
类似于WINDOWS的目录树。

 

首先，用递归方法加载树:

private void Load_TreeView(int ParentID, TreeNode pNode) { DataSet ds = new DataSet(); // 定义数据库连接 SqlConnection CN = new SqlConnection(); try { //初始化连接字符串 CN.ConnectionString = "Data Source=192.168.24.220;Integrated Security=SSPI;" + "Initial Catalog=LightCtrDB"; CN.Open(); //添加命令，从数据库中得到数据 SqlCommand sqlCmd = new SqlCommand(); sqlCmd.Connection = CN; sqlCmd.CommandText = "select * from Table2"; sqlCmd.CommandType = CommandType.Text; SqlDataAdapter adp = new SqlDataAdapter(sqlCmd); adp.Fill(ds); } catch (Exception ex) { throw (ex); } finally { CN.Close(); } //string sql = "select * from Table2"; //ds = G_SqlExecute.GetDs(sql,"Table2"); DataView dvTree = new DataView(ds.Tables[0]); //过滤ParentID,得到当前的所有子节点 dvTree.RowFilter = "[PARENTID] = " + ParentID; ArrayList Document = new ArrayList(); foreach (DataRowView Row in dvTree) { if (pNode == null) { TreeNode Node = treeView1.Nodes.Add(Row["ConText"].ToString()); Load_TreeView(Int32.Parse(Row["ID"].ToString()), Node); //再次递归 } else { //添加当前节点的子节点 TreeNode Node = pNode.Nodes.Add(Row["ConText"].ToString()); Document.Add(new ListViewItem(Row["ConText"].ToString(), 2)); pNode.Tag = Document; Load_TreeView(Int32.Parse(Row["ID"].ToString()), Node); //再次递归 } } treeView1.ImageList = imageList1; }第二种方法,另外一种形式的代码:///Summary //加载树视图代码如下： ///Summary private void Load_TreeView() { string sql = "Select * from Table2 where ParentID='0'";//选取最高一层的父节点 DataSet ds = G_SqlExecute.GetDs(sql, "T"); for (int i = 0; i < ds.Tables["T"].Rows.Count; i++) { //加载父节点 TreeNode Node = new TreeNode(); Node.Text = ds.Tables["T"].Rows[i][1].ToString(); TreeView1.Nodes.Add((TreeNode)Node.Clone());//ConText TreeView1.Nodes[i].Tag = ds.Tables["T"].Rows[i][2].ToString(); //ParentID TreeView1.Nodes[i].Name = ds.Tables["T"].Rows[i][0].ToString(); //ID TreeView1.Nodes[i].Nodes.Add("0"); } TreeView1.ImageList = imageList1; }/////Summary //展开树节点加载该树节点下的子节点： /////Summary private void treeView1_BeforeExpand(object sender, TreeViewCancelEventArgs e)//在树结点展开之前做一些处理 { e.Node.ImageIndex = 1; e.Node.SelectedImageIndex = 1; TreeNode currentNode = new TreeNode(); e.Node.Nodes.Clear(); currentNode = e.Node; parent = currentNode.Name;//获取当前选中的节点的ID string sql = "Select * from Table2 where ParentID='" + parent + "'"; DataSet ds = G_SqlExecute.GetDs(sql, "T"); for (int x = 0; x < ds.Tables[0].Rows.Count; x++) { currentNode.Nodes.Add(ds.Tables[0].Rows[x][1].ToString());//ConText currentNode.Nodes[x].Tag = ds.Tables[0].Rows[x][2].ToString();//ParentID currentNode.Nodes[x].Name = ds.Tables[0].Rows[x][0].ToString();//ID currentNode.Nodes[x].Nodes.Add("0"); } }TreeView与ListView的关联: private void treeView1_BeforeExpand(object sender, TreeViewCancelEventArgs e) { e.Node.ImageIndex = 1; e.Node.SelectedImageIndex = 1; TreeNode currentNode = new TreeNode(); e.Node.Nodes.Clear(); currentNode = e.Node; parent = currentNode.Name; string sql = "Select * from Table2 where ParentID='" + parent + "'"; DataSet ds = G_SqlExecute.GetDs(sql, "T"); ArrayList Document = new ArrayList(); for (int x = 0; x < ds.Tables[0].Rows.Count; x++) { currentNode.Nodes.Add(ds.Tables[0].Rows[x][1].ToString());//ConText Document.Add(new ListViewItem(ds.Tables[0].Rows[x][1].ToString(), 2)); currentNode.Nodes[x].Tag = ds.Tables[0].Rows[x][2].ToString();//ParentID currentNode.Nodes[x].Name = ds.Tables[0].Rows[x][0].ToString();//ID currentNode.Nodes[x].Nodes.Add("0"); } currentNode.Tag = Document; } private void TreeView1_AfterExpand(object sender, TreeViewEventArgs e) { try { listView2.Items.Clear(); ArrayList Document = (ArrayList)e.Node.Tag; if (Document != null) { foreach (ListViewItem lvi in Document) { listView2.Items.Add(lvi); } } else return; } catch (Exception ex) { MessageBox.Show("错误:" + ex.ToString()); } listView2.SmallImageList = imageList2; listView2.View = View.List; }