1 private DataTable CreateDataTable() 2         { 3             DataTable table = new DataTable(); 4             DataColumn column1 = new DataColumn("Id", typeof(string)); 5             DataColumn column2 = new DataColumn("Text", typeof(String)); 6             DataColumn column3 = new DataColumn("ParentId", typeof(string)); 7             table.Columns.Add(column1); 8             table.Columns.Add(column2); 9             table.Columns.Add(column3);10 11             DataRow row = table.NewRow();12             row[0] = "china";13             row[1] = "中国";14             row[2] = DBNull.Value;15             table.Rows.Add(row);16 17             row = table.NewRow();18             row[0] = "henan";19             row[1] = "河南省";20             row[2] = "china";21             table.Rows.Add(row);22 23             row = table.NewRow();24             row[0] = "zhumadian";25             row[1] = "驻马店市";26             row[2] = "henan";27             table.Rows.Add(row);28 29             row = table.NewRow();30             row[0] = "luohe";31             row[1] = "漯河市";32             row[2] = "henan";33             table.Rows.Add(row);34 35             row = table.NewRow();36             row[0] = "anhui";37             row[1] = "安徽省";38             row[2] = "china";39             table.Rows.Add(row);40 41             row = table.NewRow();42             row[0] = "hefei";43             row[1] = "合肥市";44             row[2] = "anhui";45             table.Rows.Add(row);46 47             row = table.NewRow();48             row[0] = "golden";49             row[1] = "金色池塘小区";50             row[2] = "hefei";51             table.Rows.Add(row);52 53             row = table.NewRow();54             row[0] = "ustc";55             row[1] = "中国科学技术大学";56             row[2] = "hefei";57             table.Rows.Add(row);58 59             return table;60         }

 1 private void LoadData() 2         { 3             // 模拟从数据库返回数据表 4             DataTable table = CreateDataTable(); 5             DataSet ds = new DataSet(); 6             ds.Tables.Add(table); 7             ds.Relations.Add("TreeRelation", ds.Tables[0].Columns["Id"], ds.Tables[0].Columns["ParentId"]); 8  9             foreach (DataRow row in ds.Tables[0].Rows)10             {11                 if (row.IsNull("ParentId"))12                 {13                     TreeNode node = new TreeNode();14                     node.Text = row["Text"].ToString();15                     node.Expanded = true;16                     tree.Nodes.Add(node);17                     ResolveSubTree(row, node);18                 }19             }20         }

 1 private void ResolveSubTree(DataRow dataRow, TreeNode treeNode) 2         { 3             DataRow[] rows = dataRow.GetChildRows("TreeRelation"); 4             if (rows.Length > 0) 5             { 6                 treeNode.Expanded = true; 7                 foreach (DataRow row in rows) 8                 { 9                     TreeNode node = new TreeNode();10                     node.Text = row["Text"].ToString();11                     treeNode.ChildNodes.Add(node);12                     ResolveSubTree(row, node);13                 }14             }15         }