window.onload与$(function(){});的区别

在window.onload的方法体中加入对AutoDropdownlist的索引改变事件，而在$(function(){
});写入不需要依赖任何动态控件生成顺序的 脚本，如不是动态生成的控件的前台js事件代码如下：

 window.onload = function () {
            //料号下拉框回车事件
            $("#MainContent_MainContent_ddlImgNo").next().keydown(function () {
                var currentVal = $(this).val();
                if (event.keyCode == 13) {
                    //debugger;
                    //只有当项号为空的时候才加载
                    var contrItemVal = $("#MainContent_MainContent_ddlContrItem").next().val();
                    LoadGoodsInfo(true, false, contrItemVal == "");
                    $("input[id$='txtPoSoNo']").focus();

                    processOptions($("#MainContent_MainContent_ddlImgNo option"), currentVal, "MainContent_MainContent_ddlImgNo");
                    $("#MainContent_MainContent_ddlImgNo").val(currentVal);
                    $("#MainContent_MainContent_ddlImgNo").next().val(currentVal);

                }
            });
            //项号下拉框回车事件
            $("#MainContent_MainContent_ddlContrItem").next().keydown(function () {
                var currentValItem = $(this).val();
                if (event.keyCode == 13) {
                    //只有当料号为空的时候才加载
                    var imgNoVal = $("#MainContent_MainContent_ddlImgNo").next().val();
                    LoadGoodsInfo(false, imgNoVal == "", false);

                    $("#MainContent_MainContent_ddlImgNo").next().focus();

                    processOptions($("#MainContent_MainContent_ddlContrItem option"), currentValItem, "MainContent_MainContent_ddlContrItem");

                    $("#MainContent_MainContent_ddlContrItem").val(currentValItem);
                    $("#MainContent_MainContent_ddlContrItem").next().val(currentValItem); //项号
                }
            });

            this.add();
        };

给GridView添加click事件
$(function () {
            $("#MainContent_MainContent_ddlImgNo").focus();
            $('.grid tr:gt(0)').click(function () {
                //默认表头不加事件
                var oid = $(this).find(':checkbox').val();
                if (oid != null && oid != "") {
                    loadBillListData(oid);
                }
            });
        });