点滴积累【C#】---TreeView读取数据库
效果：
数据库：
思路：
利用for遍历，然后创建父节点，再根据父节点创建出子节点。
代码：
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using System.Web.UI; 6 using System.Web.UI.WebControls; 7 using System.Data; 8 using System.Collections; 9 using System.Configuration; 10 using System.Data.SqlClient; 11 12 13 14 namespace TreeView 15 { 16 public partial class TreeView : System.Web.UI.Page 17 { 18 string connection = ConfigurationManager.ConnectionStrings["SQLconnection"].ToString(); 19 protected void Page_Load(object sender, EventArgs e) 20 { 21 select(); 22 CreateTree(); 23 } 24 DataSet ds = new DataSet(); 25 public DataSet DataS(string sql, string tablename) 26 { 27 SqlConnection con = new SqlConnection(connection); 28 SqlDataAdapter sqlda = new SqlDataAdapter(sql, con); 29 sqlda.Fill(ds, tablename); 30 return ds; 31 } 32 33 //ParentMenu:父节点, 34 //Grade:标识这是第几级节点, 35 //Flag:标识是不是尾结点，1是 0 不是, 36 //href:指向的链接 37 public void select() 38 { 39 string sql = "select * from treeview"; 40 ds = DataS(sql, "test"); 41 } 42 43 public void CreateTree() 44 { 45 try 46 { 47 DataTable dt = ds.Tables["test"]; 48 SortedList sl = new SortedList(); 49 TreeNode tn = new TreeNode(); 50 if (dt.Rows.Count <= 0) 51 { 52 tn.Text = "空"; 53 tn.Value = ""; 54 tn.NavigateUrl = ""; 55 tn.Target = ""; 56 tn.Expanded = false; 57 tn.SelectAction = TreeNodeSelectAction.SelectExpand; 58 59 } 60 else 61 { 62 for (int i = 0; i < dt.Rows.Count; i++) 63 { 64 //创建父节点 65 if (dt.Rows[i]["Grade"].ToString() == "1") 66 { 67 TreeNode node = new TreeNode(); 68 node.Text = dt.Rows[i]["MenuName"].ToString(); 69 node.Value = dt.Rows[i]["MenuID"].ToString(); 70 if (dt.Rows[i]["Flag"].ToString() == "1") 71 { 72 node.NavigateUrl = dt.Rows[i]["href"].ToString(); 73 tn.Target = "_bank"; 74 } 75 node.Expanded = false; 76 node.SelectAction = TreeNodeSelectAction.Expand; 77 sl.Add(node.Value, node); 78 tv_Method.Nodes.Add(node); 79 } 80 else 81 { 82 //查找父节点 83 TreeNode ParentNod = (TreeNode)sl.GetByIndex(sl.IndexOfKey(dt.Rows[i]["ParentMenu"].ToString())); 84 //创建子节点 85 TreeNode tnChild = new TreeNode(); 86 tnChild.Text = dt.Rows[i]["MenuName"].ToString(); 87 tnChild.Value = dt.Rows[i]["MenuID"].ToString(); 88 if (dt.Rows[i]["Flag"].ToString() == "1") 89 { 90 tnChild.NavigateUrl = dt.Rows[i]["href"].ToString(); 91 tnChild.Target = "_bank"; 92 } 93 tnChild.Expanded = false; 94 tnChild.SelectAction = TreeNodeSelectAction.Expand; 95 sl.Add(tnChild.Value, tnChild); 96 ParentNod.ChildNodes.Add(tnChild); 97 } 98 } 99 } 100 } 101 catch (Exception ex) 102 { 103 throw ex; 104 } 105 } 106 } 107 }
