Jquery Deferred objects

来源：互联网发布：super() python 编辑：程序博客网时间：2024/06/14 12:02

以前写的，后来想不起来了。写在这里以便查找

Deferred objects对我来说就是如果页面里面有两个ajax call对数据库进行操作。比如说两个grid 读取，Ajax执行异步操作的时候，页面显示loading...; 当两个操作都完成时，loading 隐藏

以下是代码片断

  $(document).ready(function(e) {                                                var _loadingImageContainer = $('#IA5010_2_loadingImageContainer_outer');                        _loadingImageContainer.removeClass("hidden");                        var _outer_groupcategorysection =$('#outer_groupcategorysection');                        var _outer_attr=$('#outer_attr');                        _outer_groupcategorysection.addClass("hidden");                        _outer_attr.addClass("hidden");                        var get_para=JSON.stringify({ EnvironmentId: <%=Me.EnvironmentId %>, Company: <%=Me.CompanyNumber%>,                             Department: '<%=IA5010_2_Department.Text%>', SizeratioId: <%=CInt(HiddenSizeRatioID.Value)%>});                        var get_groupcategorysection=AjaxWrapper( '<%= ResolveUrl("~/IA_Allocation_Vb/IA5010D.aspx/GetGroupCategorySection")%>',get_para);                        var get_attr=AjaxWrapper( '<%= ResolveUrl("~/IA_Allocation_Vb/IA5010D.aspx/GetProductAttributes")%>',                                                     get_para);                        var loadingdata=$.when (get_groupcategorysection,get_attr);                        //success                        loadingdata.done(function(data_groupcategorysection,data_attr){  //当两个异步操作成功的时候被调用                                                    IA5010_1_populatedata(data_groupcategorysection,data_attr);                                                                           });  //loading data done                        loadingdata.always(function(){   //无论成功与否，这个函数都会被调用。把loading隐藏写在这里                            _loadingImageContainer.addClass("hidden");                            _outer_groupcategorysection.removeClass("hidden");                            _outer_attr.removeClass("hidden");                                                              });                        //deal with fail                        loadingdata.fail(function(){                                            })                                    });  //document ready                function AjaxWrapper(webMethodrul, parameterListInJsonFormat) {                    var promiseObject = $.ajax({                        url: webMethodrul,                        contentType: "application/json; charset=utf-8",                        type: "POST",                        data: parameterListInJsonFormat,                        dataType: "json",                        cache: false,                    });                    return promiseObject;                }

0 0