前端小记

“简单地记一下这段时间所遇到的前端知识点”
1.用于重新计算iframe高度

function getHeight() {
    var iframe = parent.document.getElementById('iframe0');
    var _navLeft = parent.document.getElementById('nav-left');
    if ($(iframe).length > 0) {
        $(iframe).height(getHeightFromIframe(iframe));
        $(_navLeft).height(getHeightFromIframe(iframe) + 102);
        // IE8 下该事件只触发了一次
        if (iframe.attachEvent) {
            iframe.attachEvent("onload", function () {
                $(iframe).height(getHeightFromIframe(iframe));
                $(_navLeft).height(getHeightFromIframe(iframe) + 102);
            });
        } else {
            iframe.onload = function () {
                $(iframe).css("min-height", "530px");
                $(iframe).height(getHeightFromIframe(iframe));
                $(_navLeft).height(getHeightFromIframe(iframe) + 102);
            };
        }
    }
}
function getHeightFromIframe(selector) {
    return $(selector).contents().find('body').height() + 200;
}

2.PC端窗口缩放，页面布局不发生改变，只要在该页面上加上min-width:？px就行了。
3.请求数据(很多种请求数据的方式，这里我只是为自己做个笔记)

function getdata(url, parm, fn, errfn) {
    $.ajax({
        url: urlPrefix + url,
        data: parm,
        type: "POST",
        dataType: "json",
        cache: false,//不取浏览器缓存
        async: true,//异步
        success: function (data) {
            fn(data);
        }, error: function (err) {
            if (err.status == "409") {//系统定义409为session超时，转换提示信息
                alert('用户信息丢失，请重新登录!');
                //window.location.href = "/Login";
            }
            hideloading();
            //alert("出错了" + JSON.stringify(err));
            errfn && errfn(err)
        }, complete: function () {
        }
    });
}

4.获取浏览器地址栏？后面的参数

function getQueryString(name) {
    var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
    var r = window.location.search.substr(1).match(reg);
    if (r != null) return unescape(r[2]);
    return null;
}

5.iframe的回到顶部

function backtotop() {
    window.parent.scrollTo(0, 0);
}

6.请求页面

function getHTML(url, parm, fun) {
    $.ajax({
        url: urlPrefix + url,    //请求的url地址
        dataType: "html",   //返回格式为json
        async: true, //请求是否异步，默认为异步，这也是ajax重要特性
        data: parm,    //参数值
        type: "GET",   //请求方式
        beforeSend: function () {
            //请求前的处理
        },
        success: function (req) {
            fun(req);
        },
        complete: function () {
        },
        error: function () {
            popWindow(0, '获取页面失败!', 1400);
            $("#about").modal();

        }
    });
}

7.格式化日期

dateForm(new Date()) 获取当前系统时间

//只有一位数时前面补0
function appendzero(obj) {
    if (obj < 10) return "0" + "" + obj;
    else return obj;
}
function dateForm(time) {
    var data = new Date(time);
    var year = data.getFullYear();  //获取年
    var month = data.getMonth() + 1;    //获取月
    var day = data.getDate(); //获取日
    time = year + "-" + appendzero(month) + "-" + appendzero(day);
    return time;
}

8.计算6个月前的时间

function lessSixMonth(time) {
    var startDate = new Date(time);
    var firstdate = new Date(startDate.setMonth(startDate.getMonth()-6));
    return firstdate;
}

var firstdate = new Date(year, month, 1); //取指定月的第一天
var endDate = (new Date(firstdate.getTime() - 1000 * 60 * 60 * 24));//获取指定月最后一天

9.悬浮

//有iframe用window.parent.document，没有用document
 $(window.parent.document).scroll(function () {
        var scrollheight = parseInt($(window.parent.document).scrollTop());
        if (scrollheight >= 660) {
            $("#chartTab").css({
                "position": "fixed",
                "top": parseInt($(window.parent.document).scrollTop()) - 145 + "px"
            });
        } else if (scrollheight < 660) {
            $("#chartTab").css({
                "position": "relative",
                "top": "0px"
            });
        }
    });

10.在IE8不支持background-size，解决办法用过滤

.f-content{
    margin-top:40px;
    height: 480px;
    font-size: 16px;
    text-align: center;
    background-image: url('D:/BF/Desktop/DFI COC/images/funnel.png');
    background-size: cover;
    -ms-filter:"progid:DXImageTransform.Microsoft.AlphaImageLoader(src='D:/BF/Desktop/DFI COC/images/funnel.png',sizingMethod='scale')";
    filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(
    src='D:/BF/Desktop/DFI COC/images/funnel.png',
    sizingMethod='scale');
}
 <!--[if IE 8]>
    <style type="text/css">
    .f-content{
    margin-top:40px;
    height: 480px;
    font-size: 16px;
    text-align: center;
    background-image: none;
    background-size: cover;
    -ms-filter:"progid:DXImageTransform.Microsoft.AlphaImageLoader(src='D:/BF/Desktop/DFI COC/images/funnel.png',sizingMethod='scale')";
    filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(
    src='D:/BF/Desktop/DFI COC/images/funnel.png',
    sizingMethod='scale');
}
</style>
<![endif]-->

网上说图片最好用绝对路径，貌似用相对路径也行呵！

暂时记下这几点。。。。