Intersoft Community - Lounge - Node Expand Event

Node Expand Event

shailendra.senger — Tue, 17 May 2016 15:03:09 GMT

Ideally your solution should work but unfortunately it is not. When you searched a node full post-back occurs which again resets the scroll position on top. ScrollIntoView() function only works if it is being called when searched node's parents(or say immediate parent ) expands.Please remember my application requires treeview to bind it at runtime from code behind and also using full postback.

Node Expand Event

yudi — Tue, 17 May 2016 08:03:37 GMT

... This solution fails in a situation where searched node's grand parent is collapsed but its childrens are expanded. ...

Please check out the snippet of JS function below.

function FindNextNode()
{
    var tv = ISGetObject("WebTreeView1");
    var searchText = document.getElementById("txtSearch").value;
    if(searchText != "")
    {
        var node = tv.FindNextNodeByText(searchText);
        if (node != null)
        {                
            //node.Select();
            node.ExpandHierarchyAndSelect();
            node.GetElement().scrollIntoView();                
        }
        else
            alert("The search text can't be found");
    }
    else
        alert("Please fill in the search text");
}

I use this JS function to search WebTreeViewNode by text. ExpandHierarchyAndSelect() is called instead of invoking the Select() method. This method, ExpandHierarchyAndSelect(), will expands and selects nodes in a hierarchy.

After hierarchy is expanded and node get selected, invoke scrollIntoView() to scrolls the selected node element into the visible area of the browser window.

This should helps.

Node Expand Event

shailendra.senger — Mon, 16 May 2016 21:48:11 GMT

I am binding treeview at runtime by processing a List<T> appropriatly as a datasource where T is a class. Since Treeview doesn't have any inbuilt function which can make the searched node visibile to user. If treeview has large number of nodes than searching a bottom node always resides in bottom and scroll bar doesn't set appropriatly to bring that node up. However I got a work around to call ScrollIntoView() function, for searched node, on node expand event. This solution fails in a situation where searched node's grand parent is collapsed but its childrens are expanded. So when a grandparent expanded, its OnNodeExpand event fires for it only, not for its children as they already expanded.

Please let me know how can I trigger OnNodeExpand event for all children nodes as well (no matter if they already expanded).