Check/Uncheck on TreeView Node Click in ASP.NET CORE

21 Aug 202614 minutes to read

You can check and uncheck the checkboxes of TreeView by clicking the tree node using the nodeClicked event of TreeView.

CSHTML

<ejs-treeview id="treedata"  showCheckBox="true" nodeClicked="nodeCheck" keyPress="nodeCheck">
        <e-treeview-fields dataSource="ViewBag.dataSource" id="id" parentId="pid" text="name" hasChildren="hasChild" expanded="expanded" selected="is_selected"></e-treeview-fields>
 </ejs-treeview>

<script>
    function nodeCheck(args){
        var checkedNode = [args.node];
        var treeObj = document.getElementById('treedata').ej2_instances[0];
        if (args.event.target.classList.contains('e-fullrow') || args.event.key == "Enter") {
            var getNodeDetails = treeObj.getNode(args.node);
            if (getNodeDetails.isChecked == 'true') {
                treeObj.uncheckAll(checkedNode);
            } else {
                treeObj.checkAll(checkedNode);
            }
        }
    }
</script>

Nodecheck.cs

public IActionResult CheckBox()
        {
            List<object> treedata = new List<object>();
            treedata.Add(new
            {
                id = 1,
                name = "Australia",
                hasChild = true,
                expanded = true
            });
            treedata.Add(new
            {
                id = 2,
                pid = 1,
                name = "New South Wales",

            });
            treedata.Add(new
            {
                id = 3,
                pid = 1,
                name = "Victoria"
            });

            treedata.Add(new
            {
                id = 4,
                pid = 1,
                name = "South Australia"
            });
            treedata.Add(new
            {
                id = 6,
                pid = 1,
                name = "Western Australia",

            });
            treedata.Add(new
            {
                id = 7,
                name = "Brazil",
                hasChild = true
            });
            treedata.Add(new
            {
                id = 8,
                pid = 7,
                name = "Paraná"
            });
            treedata.Add(new
            {
                id = 9,
                pid = 7,
                name = "Ceará"
            });
            treedata.Add(new
            {
                id = 10,
                pid = 7,
                name = "Acre"
            });
            treedata.Add(new
            {
                id = 11,
                name = "China",
                hasChild = true
            });
            treedata.Add(new
            {
                id = 12,
                pid = 11,
                name = "Guangzhou"
            });
            treedata.Add(new
            {
                id = 13,
                pid = 11,
                name = "Shanghai"
            });
            treedata.Add(new
            {
                id = 14,
                pid = 11,
                name = "Beijing"
            });
            treedata.Add(new
            {
                id = 15,
                pid = 11,
                name = "Shantou"

            });
            treedata.Add(new
            {
                id = 16,
                name = "France",
                hasChild = true

            });
            treedata.Add(new
            {
                id = 17,
                pid = 16,
                name = "Pays de la Loire"

            });
            treedata.Add(new
            {
                id = 18,
                pid = 16,
                name = "Aquitaine"

            });
            treedata.Add(new
            {
                id = 19,
                pid = 16,
                name = "Brittany"

            });
            treedata.Add(new
            {
                id = 20,
                pid = 16,
                name = "Lorraine"
            });
            treedata.Add(new
            {
                id = 21,
                name = "India",
                hasChild = true

            });
            treedata.Add(new
            {
                id = 22,
                pid = 21,
                name = "Assam"

            });
            treedata.Add(new
            {
                id = 23,
                pid = 21,
                name = "Bihar"
            });
            treedata.Add(new
            {
                id = 24,
                pid = 21,
                name = "Tamil Nadu"

            });
            ViewBag.dataSource = treedata;
            return View();
        }

The output will look like the image below: