child nodes in treeview control automatically checked when parent node checked - asp.net

Question

I'm using TreeView control. Binding values from database with check box.
Nearly three children are there for parent node like
Parent1
child1
child2
child3
Parent2
child1
child2
child3
I can able to bind data which is from 3 tables all are working well. I want a facility when a parent node checks all its corresponding child automatically get checked.If I click on parent 1 ,child 123 get checked. If I check child1, child2 and child3 get checked. If I check child 2 all child 3 items get checked. How to do that?
Thanks in Advance
Amrutha

Answer 1

The javascript function below can be used to check all child nodes if the parent is checked and check parent node if at least one child node is checked otherwise it is unchecked:
function OnTreeClick(evt) {
var src = window.event != window.undefined ? window.event.srcElement : evt.target;
var isChkBoxClick = (src.tagName.toLowerCase() == "input" && src.type == "checkbox");
var t = GetParentByTagName("table", src);
if (isChkBoxClick) {
var parentTable = GetParentByTagName("table", src);
var nxtSibling = parentTable.nextSibling;
if (nxtSibling && nxtSibling.nodeType == 1) {
if (nxtSibling.tagName.toLowerCase() == "div") {
CheckUncheckChildren(parentTable.nextSibling, src.checked);
}
}
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;
var isAllSiblingsChecked = AreAllSiblingsChecked(srcChild);
if (isAllSiblingsChecked) {
checkUncheckSwitch = true;
}
else {
checkUncheckSwitch = false;
}
var inpElemsInParentTable = parentNodeTable.getElementsByTagName("input");
if (inpElemsInParentTable.length > 0) {
var parentNodeChkBox = inpElemsInParentTable[0];
parentNodeChkBox.checked = checkUncheckSwitch;
CheckUncheckParents(parentNodeChkBox, checkUncheckSwitch);
}
}
}
function AreAllSiblingsChecked(chkBox) {
var parentDiv = GetParentByTagName("div", chkBox);
var childCount = parentDiv.childNodes.length;
var k = 0;
for (var i = 0; i < childCount; i++) {
if (parentDiv.childNodes[i].nodeType == 1) {
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) {
//add each selected node one value
k = k + 1;
}
}
}
}
//Finally check any one of child node is select if selected yes then return ture parent node check
if (k > 0) {
return true;
}
else {
return false;
}
}
function GetParentByTagName(parentTagName, childElementObj) {
var parent = childElementObj.parentNode;
while (parent.tagName.toLowerCase() != parentTagName.toLowerCase()) {
parent = parent.parentNode;
}
return parent;
}
I used this javascript to solve my problem.

Answer 2

A simple recursive function could do that.
private bool checkTreeNodes(TreeNodeCollection nodes, bool parentChecked)
{
var isChecked = parentChecked;
foreach (TreeNode node in nodes)
{
if (node.Checked || parentChecked)
{
checkTreeNodes(node.Nodes, true);
node.Checked = true;
isChecked = true;
}
else
{
node.Checked = checkTreeNodes(node.Nodes, false);
isChecked = isChecked || node.Checked;
}
}
return isChecked;
}
use it like:
checkTreeNodes(myTree.Nodes, false);