js根据id、pid把数据转为树结构
 //格式化树数据
                function toTreeData(data) {
                    var pos = {};
                    var tree = [];
                    var i = 0;
                    while (data.length != 0) {
                        if (data[i].pId == ‘0‘) {
                            tree.push({
                                id: data[i].id,
                                name: data[i].name,
                                children: []
                            });
                            pos[data[i].id] = [tree.length - 1];
                            data.splice(i, 1);
                            i--;
                        } else {
                            var posArr = pos[data[i].pId];
                            if (posArr != undefined) {
                                var obj = tree[posArr[0]];
                                for (var j = 1; j < posArr.length; j++) {
                                    obj = obj.children[posArr[j]];
                                }
                                obj.children.push({
                                    id: data[i].id,
                                    name: data[i].name,
                                    children: []
                                });
                                pos[data[i].id] = posArr.concat([obj.children.length - 1]);
                                data.splice(i, 1);
                                i--;
                            }
                        }
                        i++;
                        if (i > data.length - 1) {
                            i = 0;
                        }
                    }
                    return tree;
                }