JS controls the node selection of TreeView

There are many checkbox selections for controlling TreeView on the Internet, but when I try it myself, I either get an error or it is not feasible. The following writing method is proven and effective. It is for reference only. The thinking is more clever!

Tree:

<asp:TreeView ID="treeViewDapartment" runat="server" SelectedNodeStyle-BackColor="GrayText" onclick="javascript:NodeCheck();"
     Font-Size="13px" ShowCheckBoxes="All" ShowLines="true" AutoGenerateDataBindings="false" ShowExpandCollapse="true" >
</asp:TreeView>

Script:

<script language="javascript" type="text/javascript">
   //节点父节点选中子节点全选
   function NodeCheck() { 
      var o = window.event.srcElement;
      if (o.tagName == "INPUT" && o.type == "checkbox") //点击treeview的checkbox是触发
      {
        var d = o.id; //获得当前checkbox的id;
        var e = d.replace("CheckBox", "Nodes"); //通过查看脚本信息,获得包含所有子节点div的id
        var div = window.document.getElementById(e); //获得div对象
        if (div != null) //如果不为空则表示,存在自节点
        {
          var check = div.getElementsByTagName("INPUT"); //获得div中所有的已input开始的标记
          for (i = 0; i < check.length; i++) {
            if (check[i].type == "checkbox") //如果是checkbox
            {
              check[i].checked = o.checked; //字节点的状态和父节点的状态相同,即达到全选
            }
          }
        }
        else //点子节点的时候,使父节点的状态改变,即不为全选
        {
          var divid = o.parentElement.parentElement.parentElement.parentElement.parentElement; //子节点所在的div  
          var id = divid.id.replace("Nodes", "CheckBox"); //获得根节点的id
 
          var checkbox = divid.getElementsByTagName("INPUT"); //获取所有子节点数
          var s = 0;
          for (i = 0; i < checkbox.length; i++) {
            if (checkbox[i].checked) //判断有多少子节点被选中
            {
              s++;
            }
          }
          if (s == checkbox.length) //如果全部选中 或者 选择的是另外一个根节点的子节点 ，
          {                //  则开始的根节点的状态仍然为选中状态
            window.document.getElementById(id).checked = true;
          }
          else {                //否则为没选中状态
            window.document.getElementById(id).checked = false;
          }
        }
 
      }
  }
</script>

The writing method of this script cleverly uses the relationship between the checkbox and the sub-node div in the generated page source file!

Then, just register the trigger event:

protected void Page_Load(object sender, EventArgs e)
{ 
    this.treeViewDapartment.Attributes.Add("onclick", "NodeCheck();");
 
}