How to Populate treeview Control in Visual Basic (VB.NET)
from db (access)
That really depends on your data. In general, you need to create a TreeView first and then populate it with nodes. I did that in C# once which is similar to VB. The documentation of Microsoft is quite helpful. In C# you would start with something like this:
var myTreeView = new TreeView();
myTreeView.Nodes.Add("root");
This would create a TreeView with one node. The Nodes property is a list of child nodes. Every TreeNode also has this property, so you can use it combined with indexing to select the node you want. f.e. myTreeView.Nodes[0].Nodes.Add("child") would add a child node to the root node.
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Please, let me know in what way we can programmatically know if node in kendo treeview structure has childrens ?
Need to apply corresponding class for nodes which has children...
Thank you !
Look at this demo. They use ngClass in the node template to set the icon displayed on the node.
You can also check if a node has children by using the hasChildren(item) method of the TreeView.
I have a treeview bound to a remote service. The service returns JSON and builds the tree; no problem with any of that.
I have a toolbar associated with the tree that allows a user to perform operations on the tree. The actions each toolbar option takes is dependent on data carried in the JSON that provides the datasource for the tree. I grab this data like so:
selectedNode = $("#treeview").data("kendoTreeView").select();
item = $("#treeview").data("kendoTreeView").dataItem(selectedNode);
This, however, fails on IE8, with the message "This object does not support this action."
I've tried a few variants on this, but so far no go. What am I doing wrong here?
I have hierarchical data for the tree and I want to show only part of the leaves and later to add more leaves to the tree when a button is clicked for example.
One solution I thought of is to remove all unnecessary items from the data and to add items to the data when I want to add them to the tree view.
I wonder whether there is another solution without adding/removing items from/to the data?
You can filter the data source or hide some of the .k-item elements with jQuery.
I have an handler shared between several TreeViews.
In the handler I have access to a TreeItem instance, is there a (simple) way to determine the TreeView it belongs to?
Currently I'm relying on external variables to record the "currently active" TreeView, but that makes the code messy and, probably also rather brittle. Is there an alternative?
I think it is currently not possible, at least on JavaFX 2.2. Looking at TreeView source code (available here), the TreeView.setRoot(TreeItem<T> root) method just sets the TreeView's root property, without setting some reference back to the TreeView on the root item. In this case, from the root element, there is no reference to the TreeView which it was inserted in.
Thus, even if it is possible to reach the root item from a deeper one using TreeItem.getParent(), it is not possible to reach the TreeView that has the item.
The base problem is I have a TreeGrid that I has a significant number of nodes (over 6k) and I want to be able to load a branch when the user expands a node rather than loading all at once.
I know this is possible in jqGrid (the documentation indicates so just very poorly worded http://www.trirand.com/jqgridwiki/doku.php?id=wiki:adjacency_model ) but what I can't figure out is the precise set of jqGrid settings I need to make it do that.
I do have a functional TreeGrid that will load all records from the 'url' parameter, so the only trick I need is for it to only load the top node alone, and then load it's children when I click the ExpandRow.
Figured it out myself:
The first key is setting loaded=false in the child nodes I don't want loaded. Then I need to respond the request jqGrid sends on unloaded nodes with the right nodes.