ajax二级联动代码实例

//二级联动
$(function () {
    var _in_progress = false;
    function check_in_progress() {
        if (_in_progress == true)
            return false;
        return true;
    }
    function finish_in_progress() {
        _in_progress = false;
    }

    if (check_in_progress()) {
        //获取一级下拉数据，加载页面时加载数据
        $.ajax({
            type: "post",
            url: "/Resources/askCat.ashx",
            success: function (data) {
                var listarr = eval(data);
                if (listarr != null)
                    selectinit(listarr, "selectCatId");
            },
            dataType: "json"
        });
        finish_in_progress();
    }

    //第一个下拉的onchange事件绑定
    $("#selectCatId").change(function () {

        if ($(this).val() == 0) {
            $("#selectCatId2").hide();
        } else {
            $("#selectCatId2").show();
            select2datasouse($(this).val());
        }
    });
});

//获取二级下拉的数据(ajax)
function select2datasouse(catid) {
    $.ajax({
        type: "post",
        data: { "catid": catid },
        url: "/Resources/askCat.ashx",
        success: function (data) {
            var da = eval(data);
            if (da != null)
                selectinit(da, "selectCatId2");
        },
        dataType: "json"
    });
}

//加载数据
function selectinit(data, selectid) {
    if (data != null) {
        var $select1 = $("#" + selectid);
        $select1.empty();
        $("<option/>").attr("value", "0").html("--请选择--").appendTo($select1);
        $.each(data, function (i, v) {
            $("<option/>").attr("value", v.AskCatId).html(v.Title).appendTo($select1);
        });
    }
}