JQuery autocomplete获得焦点触发弹出下拉框

需求：autocomplete控件，当点击获得焦点的时候也要弹出下拉列表（autocomplete默认是输入之后才会跟随出下拉列表），下面直接贴代码。

js代码：

$("#customerName").autocomplete({

            minLength: 0,

            source: function (request, response) {

                var customerName = $("#customerName").val();

                $.ajax({

                    url: "/api/pmstransaction/getcustomerinfo",

                    dataType: "json",

                    data: {

                        customerName: customerName

                    },

                    success: function (data) {

                        response(data.Data);

                    }

                });

            },

            focus: function (event, ui) {

                $("#customerName").val(ui.item.CustomerName);

                return false;

            },

            select: function (event, ui) {

                module.viewModel.customerInfo.CustomerName(ui.item.CustomerName);

                module.viewModel.customerInfo.CustomerTaxCode(ui.item.CustomerTaxCode);

                module.viewModel.customerInfo.CustomerAddressPhone(ui.item.CustomerAddressPhone);

                module.viewModel.customerInfo.CustomerBankAccount(ui.item.CustomerBankAccount);

                return false;

            }

        }).focus(function () {

            $(this).autocomplete("search");

        }).autocomplete("instance")._renderItem = function (ul, item) {

            return $("<li>")

                .append("<div>" + item.CustomerName + "</div>")

                .appendTo(ul);

        }

　　

　　重点代码

focus(function () {
$(this).autocomplete("search");
})