Treeview in web form checks child nodes on parent flank node check

Question

Im using the Treeview control of the System.Web.UI class to display the category and subcategory of the item.

I tried the following code but did not hope

        protected void tvwOrganisation_TreeNodeCheckChanged(object sender, TreeNodeEventArgs e)
        {
            if (tvwOrganisation.CheckedNodes.Count > 0)
            {
                // the selected nodes.
                foreach (TreeNode node in tvwOrganisation.CheckedNodes)
                {

                    if (node.ChildNodes.Count > 0)
                    {
                        foreach (TreeNode childNode in node.ChildNodes)
                        {
                            childNode.Checked = true;
                        }
                    }

                }

            }
}

Is there a way I can do this, I tried javascript too.

Also replaces AfterCheck - windows formd event in web forms.

Answer 1

The tree tag was as follows

 <asp:TreeView ID="tvwRegionCountry" runat="server" ShowCheckBoxes="All" ExpandDepth="0"   AfterClientCheck="CheckChildNodes();" PopulateNodesFromClient="true" ShowLines="true" ShowExpandCollapse="true" OnTreeNodeCheckChanged="tvwRegionCountry_TreeNodeCheckChanged"
                                                    onclick="OnTreeClick(event)">
                                                </asp:TreeView>

Added the following JS as indicated in asp.net treeview, select checkbox

<script language="javascript" type="text/javascript">
    function OnTreeClick(evt) {
        var src = window.event != window.undefined ? window.event.srcElement : evt.target;
        var isChkBoxClick = (src.tagName.toLowerCase() == "input" && src.type == "checkbox");
        if (isChkBoxClick) {
            var parentTable = GetParentByTagName("table", src);
            var nxtSibling = parentTable.nextSibling;
            if (nxtSibling && nxtSibling.nodeType == 1)//check if nxt sibling is not null & is an element node
            {
                if (nxtSibling.tagName.toLowerCase() == "div") //if node has children
                {
                    //check or uncheck children at all levels
                    CheckUncheckChildren(parentTable.nextSibling, src.checked);
                }
            }
            //check or uncheck parents at all levels
            CheckUncheckParents(src, src.checked);
        }
    }

    function CheckUncheckChildren(childContainer, check) {
        var childChkBoxes = childContainer.getElementsByTagName("input");
        var childChkBoxCount = childChkBoxes.length;
        for (var i = 0; i < childChkBoxCount; i++) {
            childChkBoxes[i].checked = check;
        }
    }

    function CheckUncheckParents(srcChild, check) {
        var parentDiv = GetParentByTagName("div", srcChild);
        var parentNodeTable = parentDiv.previousSibling;

        if (parentNodeTable) {
            var checkUncheckSwitch;

            if (check) //checkbox checked
            {
                var isAllSiblingsChecked = AreAllSiblingsChecked(srcChild);
                if (isAllSiblingsChecked)
                    checkUncheckSwitch = true;
                else
                    return; //do not need to check parent if any(one or more) child not checked
            }
            else //checkbox unchecked
            {
                checkUncheckSwitch = false;
            }

            var inpElemsInParentTable = parentNodeTable.getElementsByTagName("input");
            if (inpElemsInParentTable.length > 0) {
                var parentNodeChkBox = inpElemsInParentTable[0];
                parentNodeChkBox.checked = checkUncheckSwitch;
                //do the same recursively
                CheckUncheckParents(parentNodeChkBox, checkUncheckSwitch);
            }
        }
    }

    function AreAllSiblingsChecked(chkBox) {
        var parentDiv = GetParentByTagName("div", chkBox);
        var childCount = parentDiv.childNodes.length;
        for (var i = 0; i < childCount; i++) {
            if (parentDiv.childNodes[i].nodeType == 1) //check if the child node is an element node
            {
                if (parentDiv.childNodes[i].tagName.toLowerCase() == "table") {
                    var prevChkBox = parentDiv.childNodes[i].getElementsByTagName("input")[0];
                    //if any of sibling nodes are not checked, return false
                    if (!prevChkBox.checked) {
                        return false;
                    }
                }
            }
        }
        return true;
    }

    //utility function to get the container of an element by tagname
    function GetParentByTagName(parentTagName, childElementObj) {
        var parent = childElementObj.parentNode;
        while (parent.tagName.toLowerCase() != parentTagName.toLowerCase()) {
            parent = parent.parentNode;
        }
        return parent;
    }

</script>

and he worked ...