updatepanel 刷新 gridview太慢的解决方法,当包含dropdownlist控件时

 <script language="javascript" type="text/javascript">

        function disposeTree(sender, args) {
            var elements = args.get_panelsUpdating();
            for (var i = elements.length - 1; i >= 0; i--) {
                var element = elements[i];
                var allnodes = element.getElementsByTagName('*'),
                length = allnodes.length;
                var nodes = new Array(length)
                for (var k = 0; k < length; k++) {
                    nodes[k] = allnodes[k];
                }
                for (var j = 0, l = nodes.length; j < l; j++) {
                    var node = nodes[j];
                    if (node.nodeType === 1) {
                        if (node.dispose && typeof (node.dispose) === "function") {
                            node.dispose();
                        }
                        else if (node.control && typeof (node.control.dispose)=== "function") {
                            node.control.dispose();
                        }

                        var behaviors = node._behaviors;
                        if (behaviors) {
                            behaviors = Array.apply(null, behaviors);
                            for (var k = behaviors.length - 1; k >= 0; k--) {
                                behaviors[k].dispose();
                            }
                        }
                    }
                }
                element.innerHTML = "";
            }

        }
        Sys.WebForms.PageRequestManager.getInstance().add_pageLoading(disposeTree);

</script>