There's a problem about the method 'isLast';

[maxazan]

There's a problem about the method 'isLast';

[uranusAdam]

The problem has been solved.
isLast: function() {
var current_parent_id = $(this).treegrid('getParentNodeId');
if ($(this).next().length>0) {
if ($(this).next().treegrid('getParentNodeId') === current_parent_id) {
return false;
} else {
return true;
}
} else {
return true;
}
},

[maxazan]

Thanks for you help!
Now you can use

  $('.tree').treegrid('getAllNodes').each(function() {
    if ($(this).treegrid("isLast")) {
      $(this).find('.treegrid-expander').css("background","red");
    }
  });

or

  $('.tree').find('tr').each(function() {
    if ($(this).treegrid("isNode") && $(this).treegrid("isLast")) {
      $(this).find('.treegrid-expander').css("background","red");
    }
  });