TreeView和数据库绑定

  在网上看了天轰穿老师的TreeView这一节课，他讲的很简单，代码如下：
数据库结构：第一个表是big，第二个表是class

代码如下：
  

private   void  Form2_Load( object  sender, EventArgs e)
        {
            DataView dv  =  drv( " select bid,title from big " );
            TreeNode n  =   new  TreeNode();
            n.Text  =   " 中国地区 " ;
             this .treeView1.Nodes.Add(n);

             foreach  (DataRowView datav  in  dv)
            {
                TreeNode tn  =   new  TreeNode();
                tn.Text  =  datav[ " title " ].ToString();
                tn.Tag  =  datav[ " bid " ];
                n.Nodes.Add(tn);
                AddChildNodes(tn);

            }

             // ExpandNode(this.treeView1.Nodes);
        }

         private  DataView drv( string  sql)
        {
            SqlConnection con  =   new  SqlConnection( " server=.;database=test;uid=sa;pwd=; " );
            SqlDataAdapter sda  =   new  SqlDataAdapter(sql, con);
            DataTable dt  =   new  DataTable();
            sda.Fill(dt);
             return  dt.DefaultView;
        }

         private   void  AddChildNodes(TreeNode t)
        {
             int  bid  =  Convert.ToInt32(t.Tag.ToString());
            DataView d  =  drv( " select * from class where bid= "   +  bid);
             foreach  (DataRowView datav  in  d)
            {
                TreeNode node  =   new  TreeNode();
                node.Text  =  datav[ " title " ].ToString();
                node.Tag  =  datav[ " cid " ];
                t.Nodes.Add(node);
            }
        }
                 /*
        private void ExpandNode(TreeNodeCollection tnc)
        {
            foreach (TreeNode node in tnc)
            {
                node.Expand();
                ExpandNode(node.Nodes);
            }
        }
         */

   可是我在做项目时需要根据一个表中的数据来显示树形目录，数据库结构如下：

构件树形目录的方法如下：
 

#region  构建TreeView

         public   bool  BuildTree(TreeView tv, DataSet ds)
        {
            tv.Nodes.Clear();

             foreach  (DataRow dbRow  in  ds.Tables[ 0 ].Rows)
            {
                 if  (dbRow[ " FatherNumber " ].ToString()  ==   string .Empty)
                {
                    dbRow[ " FatherNumber " ]  =  DBNull.Value;
                }
            }
            ds.Relations.Add( " NodeRelation " , ds.Tables[ 0 ].Columns[ " TypeNumber " ], ds.Tables[ 0 ].Columns[ " FatherNumber " ],  false );

             foreach  (DataRow dbRow  in  ds.Tables[ 0 ].Rows)
            {
                 if  (dbRow.IsNull( " FatherNumber " ))
                {
                    TreeNode newNode  =  CreateNode(dbRow[ " TypeName " ].ToString(), dbRow[ " TypeNumber " ].ToString());

                    tv.Nodes.Add(newNode);
                    PopulateSubTree(dbRow, newNode);
                }
            }

             // 展开所有节点
            tv.ExpandAll();

             return   true ;
        }

         private   void  PopulateSubTree(DataRow dbRow, TreeNode node)
        {
             foreach  (DataRow childRow  in  dbRow.GetChildRows( " NodeRelation " ))
            {
                TreeNode childNode  =  CreateNode(childRow[ " TypeName " ].ToString(), childRow[ " TypeNumber " ].ToString());
                node.Nodes.Add(childNode);
                PopulateSubTree(childRow, childNode);
            }
        }

         private  TreeNode CreateNode( string  text,  string  tag)
        {
            TreeNode node  =   new  TreeNode();
            node.Text  =  text;
            node.Tag  =  tag;
             return  node;
        }

这样调用：
          

SqlConnection con  =   new  SqlConnection( " server=192.168.1.192;database=AUDE_KCGL;uid=sa;pwd=; " );
            SqlDataAdapter sda  =   new  SqlDataAdapter( " select TypeNumber,FatherNumber,TypeName from KC_ObjectType " , con);
            DataSet dsTree  =   new  DataSet();
            sda.Fill(dsTree);
             // 调用方法构件树形目录
            BuildTree( this .treeView1, dsTree);

程序运行效果：