Asp.net treeview examples how to#

Sub PopulateProducts(ByVal node As TreeNode) ' Add the new node to the ChildNodes collection of the parent node. NewNode.SelectAction = TreeNodeSelectAction.Expand ' Set additional properties for the node. ' Set the PopulateOnDemand property to true so that the child nodes can be Newnode.Value = row('CategoryID').ToString() Newnode.Text = row('CategoryName').ToString() This will make querying for items in a specific category easier when Notice that the CategoryId is stored in the Value property ' Notice that the query results are stored in the table of the DataSet. ' Iterate through and create a new node for each row in the query results. These are the valuesĭim ResultSet As DataSet = RunQuery('Select CategoryID, CategoryName From Categories') Sub PopulateCategories(ByVal node As TreeNode) ' Call the appropriate method to populate a node at a particular level. Sub PopulateNode(ByVal sender As Object, ByVal e As TreeNodeEventArgs) Message.Text = 'Unable to connect to the database.' If(DBConnection.State = ConnectionState.Open) Close the database connection if it is still open. SqlConnection DBConnection = new SqlConnection(ConnectionString) ĭBAdapter = new SqlDataAdapter(QueryString, DBConnection) String ConnectionString = 'server=localhost database=NorthWind Integrated Security=SSPI' and connects to the Northwind sample database. NewNode.SelectAction = TreeNodeSelectAction.None Set the PopulateOnDemand property to false, because these are leaf nodes and

TreeNode NewNode = new TreeNode(row.ToString()) These are the valuesĭataSet ResultSet = RunQuery('Select ProductName From Products Where CategoryID=' + node.Value) Query for the products of the current category. Add the new node to the ChildNodes collection of the parent node. Set additional properties for the node. Set the PopulateOnDemand property to true so that the child nodes can be Notice that the query results are stored in the table of the DataSet.įoreach (DataRow row in ) Iterate through and create a new node for each row in the query results. These are the valuesĭataSet ResultSet = RunQuery('Select CategoryID, CategoryName From Categories') Call the appropriate method to populate a node at a particular level. Void PopulateNode(Object sender, TreeNodeEventArgs e) When client-side node population is enabled, nodes are populated dynamically on the client, without the need to post back to the server.

Asp.net treeview examples how to#

The following code example demonstrates how to populate the nodes in the TreeView control from the client. The following code example provides sample site map data for the preceding code example. For this example to work correctly, you must copy the sample site map data, provided after this code example, to a file named Web.sitemap. The following code example demonstrates how to use the TreeView control for site navigation by binding it to a SiteMapDataSource control. The following code example provides sample XML data for the preceding example. For this example to work correctly, you must copy the sample XML data, provided after this code example, to a file named Book.xml. The following code example demonstrates how to bind the TreeView control to an XML data source. This example is used within the frame set of the preceding example to display a table of contents. The following code example demonstrates how to use declarative syntax to display static data in the TreeView control. The following code example demonstrates how to set up the frames for the following code example. The seventh code example demonstrates how to populate the nodes in the TreeView control from the client. The sixth code example provides sample site map data for the fifth code example. The fifth code example demonstrates how to use the TreeView control for site navigation by binding it to a SiteMapDataSource control. The fourth code example provides sample XML data for the third code example.

The third code example demonstrates how to bind the TreeView control to an XML data source. The second code example demonstrates how to use declarative syntax to display static data in the TreeView control. The first code example demonstrates how to set up the frames for the second code example. This section contains seven code examples: ICallbackEventHandler IPostBackDataHandler IPostBackEventHandler Examples