树2

6、treeview实现两层节点没问题，扩展到无限层就出问题了？
数据库结构如下：
表名：Table1
ParentID varchar 20:父节点
ID varchar 20:节点
Name varchar 50：名称

这里给你个例程，再给个我的网页上的TreeViwe看看，一万个子节点都没问题。
http://dev1.eraserver.net/czc888/webform1.aspx
至于那三个图象的意义你看我的网页就知道了。分别表示一页纸（没有子节点）、一本
关闭的书（有子节点），一本打开的书（当前节点被展开）

void creat_node(string
name,Microsoft.Web.UI.WebControls.TreeNode t1,string number)
{
//定义一个新的结点

Microsoft.Web.UI.WebControls.TreeNode t2=new
Microsoft.Web.UI.WebControls.TreeNode();
t2.ID=number;
t2.Text=name;

//判断是否为根结点
TreeView1.ExpandedImageUrl="images/Depart03.bmp";
if(t1.ID.Trim()=="###")
{
TreeView1.Nodes.Add(t2);
t2.ImageUrl="images/Depart01.bmp";
}
else
{
t1.Nodes.Add(t2);
t2.ImageUrl="images/Depart01.bmp";
t1.ImageUrl="images/Depart02.bmp";
}

//取得这个结点的所有子结点，利用递归自动生成
string mySelectQuery = "SELECT ParentID, ID,Name FROM table1
where ParentID='" + number +"'";
string MyConnString="provider=Microsoft.Jet.OLEDB.4.0;Data
Source="+Server.MapPath(".")+"/dt/mydata.mdb";
OleDbConnection myConnection = new
OleDbConnection(MyConnString);
OleDbCommand myCommand = new
OleDbCommand(mySelectQuery,myConnection);
myConnection.Open();
OleDbDataReader myReader;
myReader = myCommand.ExecuteReader();
while (myReader.Read())
{
creat_node(myReader.GetString(2),t2,myReader.GetString(1));
}
myReader.Close();
myConnection.Close();
}
private void CreateProviderTreeBtn_Click(object sender,
System.EventArgs e)
{
Microsoft.Web.UI.WebControls.TreeNode t1=new
Microsoft.Web.UI.WebControls.TreeNode();
creat_node("",t1,"###");
7、怎样使用TreeView???

//初始化TreeView数据
private void InitTV(int intVOrderLen)
{
SqlDataReader dr;
SqlCommand myCommand;
string strSel = "select * from bas_enterprise where
len(vieworder)="+intVOrderLen+" order by vieworder";
myCommand = new SqlCommand (strSel, myConnection);
dr=myCommand.ExecuteReader();
while (dr.Read ())
{
TreeNode pNode=new TreeNode ();
pNode.Text =dr["EntpName"].ToString ();
pNode.ID =dr["ViewOrder"].ToString ();
TreeView1.Nodes .Add (pNode);

}
dr.Close ();

}
private void TreeView1_SelectedIndexChange(object sender,
Microsoft.Web.UI.WebControls.TreeViewSelectEventArgs e)
{
TreeNode NewNode=TreeView1.GetNodeFromIndex
(TreeView1.SelectedNodeIndex);
string strNodeId=NewNode.ID .ToString ();
SqlDataReader dr;
SqlCommand myCommand;
int intVOrderLen=strNodeId.Length+2;
string strSel = "select * from bas_enterprise where
len(vieworder)="+intVOrderLen+" and vieworder like '%"+strNodeId+"__%'
order by vieworder";
myCommand = new SqlCommand (strSel, myConnection);
dr=myCommand.ExecuteReader();
NewNode.Nodes .Clear();
while (dr.Read ())
{
TreeNode pNode=new TreeNode ();
pNode.Text =dr["EntpName"].ToString ();
pNode.ID =dr["ViewOrder"].ToString ();
NewNode.Nodes.Add (pNode);
}
dr.Close ();
TreeView1.ExpandLevel=1;
}
8、在treeview中如何查找一个值，并选中它？

问题:
各位，在已经建好的树中如何查找一个文本或者是treenodes的id，找到后选中它？
答案:
for(int i=0;i<TreeView1.Nodes.Count;i++)
if(TreeView1.Nodes[i]==TextBox1.Text)
{
string index1=TreeView1.Nodes[i].GetNodeIndex();//取得index
TreeView1.SelectedNodeIndex=index1;
}

9、如何取得TreeView中各项的值？？

private void TreeView1_SelectedIndexChange(object sender,
Microsoft.Web.UI.WebControls.TreeViewSelectEventArgs e)
{
Microsoft.Web.UI.WebControls.TreeNode
NewNode=TreeView1.GetNodeFromIndex(TreeView1.SelectedNodeIndex);
Label1.Text =NewNo
如果通过代码要在父结点中增加子节点,代码如何实现?
父节点代码如下:
TreeNode pNode = new TreeNode();
pNode.ID = "Root";
pNode.Text = strNodeName;
TreeView1.Nodes.Add(pNode);
如果要在根结点"Root"下面再增加子节点,如何写代码?
TreeView1.Nodes.AddAt(pNode);这种方式好象不行.
TreeView1.Nodes[0].Nodes.Add(pNewNode);