RadControls for ASP.NET AJAX When using Templates for the Nodes of a RadTreeView, editing of the Text of these Nodes becomes a complicated task.
The approach demonstrated in the example below is an elegant way to edit Node Text, save it in a database and then populate the TreeView with the new data.
Example:
This example shows a TreeView that is bound to a database. It uses Templates for its Nodes. The Template displays the Text of Nodes using the DataBinder.Eval expression.
CopyASPX
<telerik:RadTreeView ID="RadTreeView1" runat="server" AllowNodeEditing="true" OnNodeEdit="RadTreeView1_NodeEdit">
<NodeTemplate>
node text:
<%# DataBinder.Eval(Container.DataItem"Text") %>
</NodeTemplate>
</telerik:RadTreeView>CopyC#
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
GenerateTreeView();
}
}
protected void RadTreeView1_NodeEdit(object sender, Telerik.Web.UI.RadTreeNodeEditEventArgs e)
{
RadTreeNode nodeEdited = e.Node;
string newText = e.Text;
OleDbConnection dbCon = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("~/App_Data/Tree.mdb"));
OleDbParameter pNewText = new OleDbParameter("@newText", newText);
OleDbParameter pOldText = new OleDbParameter("@oldText", nodeEdited.Text);
string cmdString = "Update Links Set [Text] = @NewText WHERE [Text] = @oldText";
OleDbCommand dbCommand = new OleDbCommand(cmdString, dbCon);
dbCommand.CommandType = CommandType.Text;
dbCommand.Parameters.Add(pNewText);
dbCommand.Parameters.Add(pOldText);
try
{
dbCon.Open();
dbCommand.ExecuteNonQuery();
}
finally
{
dbCon.Close();
}
GenerateTreeView();
}
private void GenerateTreeView()
{
OleDbConnection dbCon = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("~/App_Data/Tree.mdb"));
dbCon.Open();
OleDbDataAdapter adapter = new OleDbDataAdapter("SELECT * FROM Links", dbCon);
DataSet ds = new DataSet();
adapter.Fill(ds);
RadTreeView1.DataFieldID = "id";
RadTreeView1.DataFieldParentID = "parentId";
RadTreeView1.DataTextField = "Text";
RadTreeView1.DataSource = ds;
RadTreeView1.DataBind();
RadTreeView1.ExpandAllNodes();
}CopyVB.NET
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
GenerateTreeView()
End If
End Sub
Protected Sub RadTreeView1_NodeEdit(ByVal sender As Object, ByVal e As Telerik.Web.UI.RadTreeNodeEditEventArgs)
Dim nodeEdited As RadTreeNode = e.Node
Dim newText As String = e.Text
Dim dbCon As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("~/App_Data/Tree.mdb"))
Dim pNewText As New OleDbParameter("@newText", newText)
Dim pOldText As New OleDbParameter("@oldText", nodeEdited.Text)
Dim cmdString As String = "Update Links Set [Text] = @NewText WHERE [Text] = @oldText"
Dim dbCommand As New OleDbCommand(cmdString, dbCon)
dbCommand.CommandType = CommandType.Text
dbCommand.Parameters.Add(pNewText)
dbCommand.Parameters.Add(pOldText)
Try
dbCon.Open()
dbCommand.ExecuteNonQuery()
Finally
dbCon.Close()
End Try
GenerateTreeView()
End Sub
Private Sub GenerateTreeView()
Dim dbCon As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("~/App_Data/Tree.mdb"))
dbCon.Open()
Dim adapter As New OleDbDataAdapter("SELECT * FROM Links", dbCon)
Dim ds As New DataSet()
adapter.Fill(ds)
RadTreeView1.DataFieldID = "id"
RadTreeView1.DataFieldParentID = "parentId"
RadTreeView1.DataTextField = "Text"
RadTreeView1.DataSource = ds
RadTreeView1.DataBind()
RadTreeView1.ExpandAllNodes()
End Sub