After looking into the source, "treedata" is the raw xml data, while "record" may be modified by user interaction.

But we need to click the "span" in that column not the whole row.  It's my mistake.

{

      var grid = $("#" + gridId);
      var treedata = grid.getRowData(rowid);

      if(treedata.isLeaf == "false")

     {

        if (treedata.expanded == "false")
          {
            var record = grid.getInd(rowid, true);
            grid.expandRow(record);
            grid.expandNode(record);
          }
          else
          {
            var record = grid.getInd(rowid, true);
            grid.collapseRow(record);
            grid.collapseNode(record);
          }

        }

}

It doesn't work for collapse action.

I think the expandNode doesn't correctly set the expended to "true" cause the problem.

It seems like the ExpandColClick broken again in 3.6.1, currently we need to use onRowSelect to do it ourselves.

This is my options:

      url: XXX,
      treedatatype: "xml",
      height: "auto",
      loadui: "enable",
      colNames: XXX,
      colModel: XXX,
      treeGrid: true,
      treeGridModel: "adjacency",
      tree_root_level: 0,
      caption: XXX,
      ExpandColumn: "XXX",
      rownumbers: false,
      autowidth: true,
      ExpandColClick: true,
      pager: jQuery('#' + pagerId),
      rowNum: -1,

Thanks!