工具方法（二）

url参数序列化

    /**
     * json序列化为URLencode
     * @return {string}
     */
    let json_to_URLencode = json => {
      return Object.keys(json)
        .map(function(key) {
          return encodeURIComponent(key) + '=' + encodeURIComponent(json[key]);
        })
        .join('&');
    };

    console.log('www.baidu.com?' + json_to_URLencode({ name: 'kaka', age: 18 }));
    /**
     * URL 参数序列化
     * @param { String } baseURL ：url地址
     * @param { Object } params  ：参数对象
     * @return string: 参数序列化后的字符串
     */
    const ParamSerialize = function(baseURL, params) {
      return Object.keys(params).reduce((pre, cur) => (pre += (pre === baseURL ? '?' : '&') + `${cur}=${params[cur]}`), baseURL);
    };
    ParamSerialize('www.baidu.com', { name: '', age: 19 }); //www.baidu.com?name=&age=19
    ParamSerialize('www.baidu.com', { name: 'wuming', age: '' }); //www.baidu.com?name=wuming&age=
    ParamSerialize('www.baidu.com', { name: 'wuming', age: 19 }); //www.baidu.com?name=wuming&age=19
    ParamSerialize('www.baidu.com', {}); //www.baidu.com

url参数获取

    /**
     * 获取url参数
     * ie不兼容解决：npm install url-search-params-polyfill
     * 在index.js中引入 import 'url-search-params-polyfill';
     * **/
    let location = new URL('http://www.baidu.com?name=ronle');
    console.log(new URLSearchParams(location.search).get('name'));
    // 如果是哈希路由
    let url = 'http://www.baidu.com/#/?name=ronle';
    let location = new URL(url.split('#')[0] + url.split('#')[1]);
    console.log(new URLSearchParams(location.search).get('name'));
    /**
     * URL 参数获取
     * @param { String } url ：url地址  可选，不传则默认值是window.location.href
     * @return object
     */
    const getUrlParms = function(url) {
      return (url ? url : location.href).includes('?')
        ? (url ? url : location.href)
            .split('?')[1]
            .match(/([^&=]*)=([^&]*)/g)
            .reduce((pre, cur) => {
              pre[cur.split('=')[0]] = cur.split('=')[1];
              return pre;
            }, {})
        : {};
    };
    //测试用例
    getUrlParms('www.baidu.com?name=&age=19'); //{name: "", age: "19"}
    getUrlParms('www.baidu.com?name=wuming&age='); //{name: "ronle", age: ""}
    getUrlParms('www.baidu.com?name=wuming&age=19'); //{name: "ronle", age: "19"}
    getUrlParms('www.baidu.com'); //{}
    getUrlParms(); //当前页面的window.location.href = 'www.baidu.com?name=ronle&age=29'，则返回 {name: "wuming", age: "19"}
    getUrlParms(); //当前页面的window.location.href = 'www.baidu.com'，则返回 {}

url模板格式化

    /**
     * 请求相关:
     *
     *  @param {String}  URL: 模板路径，例：'/uap/msg/announcementRecord/{sysId}/{tenantId}/{userId}' 或 '/uap/msg/announcementRecord'
     *  @param {Object}  params: 传入的参数，包含路径参数 或 不包含
     *  @param {Boolean} flag：是否拼接路径和查询参数
     *
     *  PS：flag为true时，一定是GET请求，GET请求才会拼接参数到URL后面
     */

    function getFormatUrl(URL, params, flag = false) {
      let url = /{(w+)}/g.test(URL)
        ? URL.replace(/{(w+)}/g, (a, b) => {
            let tmp = params[b];
            delete params[b];
            return tmp;
          })
        : URL;
      return flag ? Object.keys(params).reduce((pre, cur) => (pre += (pre === url ? '?' : '&') + `${cur}=${params[cur]}`), url) : url;
    }

    //测试用例
    getFormatUrl('/uap/msg/announcementRecord/{sysId}/{tenantId}/{userId}', {
      sysId: '001',
      tenantId: '002',
      userId: '003',
      username: 'wuming',
      age: 39
    });
    //输出：/uap/msg/announcementRecord/001/002/003
    getFormatUrl(
      '/uap/msg/announcementRecord/{sysId}/{tenantId}/{userId}',
      {
        sysId: '001',
        tenantId: '002',
        userId: '003',
        username: 'wuming',
        age: 39
      },
      true
    );
    //输出：/uap/msg/announcementRecord/001/002/003?username=wuming&age=39
    getFormatUrl('/uap/msg/announcementRecord', {}); // 输出：/uap/msg/announcementRecord
    getFormatUrl('/api/getUerInfo/{userId}/{roleId}', { userId: 12, roleId: 33 }); //输出：api/getUerInfo/12/33
    getFormatUrl('/api/getUerInfo/{userId}/{roleId}', { userId: 12, roleId: 33, extraParam: '555' }); //输出：api/getUerInfo/12/33
    getFormatUrl('/api/getUerInfo/{userId}/{roleId}', { userId: 12, roleId: 33, extraParam: '555' }, true); //输出：/api/getUerInfo/12/33?extraParam=555
    console.log(getFormatUrl('/api/getUerInfo/{userId}/{roleId}', { userId: 12, roleId: 33, extraParam: '555' }, true));

随机字符串

    /**
     * 生成随机字符串
     * @param {Number} len 随机字符串的长度 随机不重复字符串长度最大为62
     * @param {Boolean} isRepeat 是否重复 默认true
     * @return 长度为len的随机字符串
     */
    const randomStr = function(count, isRepeat = true) {
      var strArr = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'.split(''),
        res = '';
      var _count = isRepeat === true ? count : count > 62 ? 62 : count;
      while (res.length < _count) {
        var random = Math.floor(Math.random() * 62);
        if (isRepeat) {
          res += strArr[random];
        } else {
          if (!res.includes(strArr[random])) {
            res += strArr[random];
          }
        }
      }
      return res;
    };
    //测试用例
    randomStr(10);
    randomStr(10, false);
    randomStr(5);
    randomStr(63, false);
    randomStr(100);

随机数

    /**
     * 生成随机数
     * @param {Number | Object} start 范围起始数字
     * @param {Number} end 范围终止数字
     * @param {Number} count 随机数个数
     * @param {Boolean} isRepeat 是否重复
     * @return 随机数数组
     */
    const randomNum = function(start, end, count, isRepeat = true) {
      let _isRepeat = true;
      if (arguments.length === 1 && arguments[0] !== null && typeof arguments[0] === 'object') {
        let { start, end, count, ...reset } = arguments[0];
        _isRepeat = reset.isRepeat === undefined ? true : reset.isRepeat === false ? false : reset.isRepeat;
      } else {
        _isRepeat = isRepeat;
      }
      let _arr = [];
      let _max_count = isRepeat ? count : end - start + 1;
      let _count = count > _max_count ? _max_count : count;

      while (_arr.length < _count) {
        let random = Math.ceil(Math.random() * end);
        let _condition = random >= start && random <= end;
        if (_condition) {
          if (_isRepeat) {
            _arr.push(random);
          } else {
            !_arr.includes(random) && _arr.push(random);
          }
        }
      }
      return _arr;
    };
    //测试用例
    randomNum(10, 20, 10);
    randomNum(0, 9, 1);
    randomNum(0, 9, 0);
    randomNum(90, 100, 5, false);

基于当前 / 指定时间的 过去 n 天时间（包含当天日期）

    /**
     * 生成 基于当前 / 指定时间的 过去 n 天时间（包含当天日期）
     * @param {Number} days 基于当前 / 指定时间的 过去 n 天时间（包含当天日期）
     * @param {Boolean} s 指定时间
     * @return string[] 日期数组
     */
    const passDaysDate = function(days, s) {
      if (!arguments.length) return [];
      return [...Array(days + 1).keys()]
        .map(days => new Date((s ? new Date(s) : Date.now()) - 86400000 * days).toLocaleDateString())
        .map(item =>
          item
            .split(//|-/)
            .map(i => i.padStart(2, '0'))
            .join('-')
        )
        .splice(1);
    };
    //测试用例
    passDaysDate(); //[]
    passDaysDate(3, '2020/3/13'); //["2020-03-12", "2020-03-11", "2020-03-10"]
    passDaysDate(3); //["2020-03-14", "2020-03-13", "2020-03-12"]
    passDaysDate(3, 1530975600000); // 13位时间戳日期是：2018/07/07 23:00:00 返回：["2018-07-06", "2018-07-05", "2018-07-04"]

生成 范围内所有日期 包含起止日期

/**
 * 生成 范围内所有日期 包含起止日期
 * @param {String | Number} startDate 开始时间
 * @param {String | Number} endDate 结束时间 选填，不填则默认值是当前日期
 * @return 数组
 */
const betweenDate = function(startDate,endDate){
    var arr=[];
    var now=new Date();
    var endDate=endDate?endDate:(now.getFullYear()+'/'+(now.getMonth()+1)+'/'+now.getDate());
    var days=parseInt(Math.abs(new Date(startDate.split(' ')[0]+' 00:00:00') - new Date(endDate.split(' ')[0]+' 00:00:00'))/1000/24/60/60)+1;
    for(let i=0;i<days;i++){
        let stamp=new Date(new Date(startDate).getTime()+i*86400000);
        arr.push(stamp.getFullYear()+'-'+String(stamp.getMonth()+1).padStart(2,0)+'-'+String(stamp.getDate()).padStart(2,0))
    }
    return arr
}
//测试用例
betweenDate('2017-01-01','2017-01-03') //["2017-01-01", "2017-01-02", "2017-01-03"]
betweenDate('2020-03-13') //当前日期：2020/3/15 ，返回 ：["2020-03-13", "2020-03-14", "2020-03-15"] 

快速生成不确定长度值不确定的数组

//方法1
function GenerateArray(len,value){
    return ','.repeat(len-1).split(',').fill(value)
}
//方法2
function GenerateArray(len,value){
    return new Array(len).toString().split(',').fill(value)
}
//方法3
function GenerateArray(len,value){
    return ','.repeat(len-1).split(',').map(i=>value)
}
//方法4
function GenerateArray(len,value){
    return new Array(len).toString().split(',').map(i=>value)
}
//方法5
function GenerateArray(len,value){
    return new Array(len).fill(value)
}
//方法6
function GenerateArray(len,value){
    return Array(len).fill(value)
}

//测试用例

//生成长度为2 值为空对象的数组
GenerateArray(2,{}) //[{},{}]
//生成长度为5 值为0的数组
GenerateArray(5,0) //[0,0,0,0,0]
//生成长度为5 值为[]的数组
GenerateArray(5,[]) //[[],[],[],[],[]]

快速生成 值为索引递增 长度为len 的数组

function GenerateArray(len){
    return [...Array(len).keys()]
}
//测试用例
GenerateArray(10) //[0,1,2,3,4,5,6,7,8,9]

不按索引，从1开始递增

function GenerateArray(len){
    let arr = [...Array(len+1).keys()]
    arr.splice(0,1)
    return arr
}
//测试用例
GenerateArray(10) // [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

月份回显

export const previewMonth = function(i){
    return i>0&&i<13? ['一','二','三','四','五','六','七','八','九','十','十一','十二'][i-1]+'月':'Invalid month'
}
//测试用例
previewMonth(0) //Invalid month
previewMonth(1) //一月
previewMonth(2) //二月
previewMonth(3) //三月
previewMonth(4) //四月
previewMonth(5) //五月
previewMonth(6) //六月
previewMonth(7) //七月
previewMonth(8) //八月
previewMonth(9) //九月
previewMonth(10) //十月
previewMonth(11) //十一月
previewMonth(12) //十二月
previewMonth(13)//Invalid month

星期回显

const previewWeek = function(i){
    return i>0&&i<8?'周'+['一','二','三','四','五','六','日'][i-1]:'Invalid week'
}
//测试用例
previewWeek(0) //Invalid week
previewWeek(1) //周一
previewWeek(2) //周二
previewWeek(3) //周三
previewWeek(4) //周四
previewWeek(5) //周五
previewWeek(6) //周六
previewWeek(7) //周日
previewWeek(8) //Invalid week

时刻回显

const previewDate = function(target = Date.now()){
    /** 
     * 回显 规则：
     * {
     * <60s:'刚刚',
     * '>60s && 3600s':'x分钟之前',
     *  '>3600s && <86400s':'x小时之前',
     * '昨天':'昨天',
     * '前天':'前天',
     * '具体日期':'月日',
     * '不是当年':'显示年月日'
     * }
     * */
    // 时间格式参数 2018/07/08 06:05:59 | 2018-07-08 06:05:59 | 时间戳
    let targetStamp = parseInt(new Date(target).getTime()/1000)//参数转时间戳
    let diff = parseInt((Date.now()/1000 - targetStamp))// 计算 与当前时间相差秒数
    let dt =new Date();
    let today = dt.toLocaleDateString() //今天日期 年月日
    let yestoday = new Date(dt.setDate(dt.getDate() - 1)).toLocaleDateString()//昨天日期 年月日
    let beforeYestoday = new Date(dt.setDate(dt.getDate() - 1)).toLocaleDateString()//前天日期 年月日
    let todayDawnStamp = new Date(today +' 00:00:00').getTime()/1000 //2020/2/8
    let yestodayDawnStamp =new Date(yestoday +' 00:00:00').getTime()/1000 //昨天凌晨 时间戳 （秒）2020/2/7
    let beforeYestodayDawnStamp = new Date(beforeYestoday +' 00:00:00').getTime()/1000 //前天凌晨 时间戳（秒） 2020/2/6
    if(diff < 60) {
        return '刚刚'
    }else if(diff > 60 && diff <3600) {
        return parseInt(diff/60)+'分钟前'
    }else if(diff >= 3600 && diff < 86400){
        return parseInt(diff/3600)+'小时前'
    }else if( targetStamp < todayDawnStamp && targetStamp >= yestodayDawnStamp){
        return '昨天'
    }else if(targetStamp <= yestodayDawnStamp && targetStamp >= beforeYestodayDawnStamp){
        return '前天'
    }else if(targetStamp > beforeYestodayDawnStamp){
        let d = new Date(target);
        return (d.getMonth() +1) +'-'+ d.getDate()
    }else {
        let t = new Date(targetStamp*1000).toLocaleDateString();
        let c = new Date().getFullYear();
        return t.substr(0,4) == c?t.slice(5):t
    }
}
//测试用例
previewDate() //刚刚
previewDate('2020/3/14')   //昨天   测试日期：2020-3-15
previewDate('2020/3/13')   //前天 测试日期：2020-3-15
previewDate('2020/1/14')   // 1/14
previewDate('2019/12/14')  //2019/12/14

JSON 转 fromData

/**
 *  JSON 转 fromData
 *  @param {Object} o 需要转成formData 的对象
 */
 const jsonToFromData = function jsonToFromData(o){
    return Object.keys(o).reduce((p, c) => !p.append(c, o[c]) && p, new FormData())
 }
 
 //测试用例
 let FromData = jsonToFromData({
    sysId:"001",
    tenantId:"002",
    userId:"003",
    username:'wuming',
    age:39,
})
FromData // FormData{}
FromData.forEach((v,k)=>{
    console.log(k,v)
})
/**输出：
 * sysId 001
 * tenantId 002
 * userId 003
 * username wuming
 * age 39
 */

获取字符串模板内容

/**
 * 获取模板字符串里模板里的值
 * @param {String} str 模板字符串
 * @param {String} f 指定模板的左部分
 * @param {String} l 指定模板的右部分
 * @param {Number} pattern 指定模板的右部分 获取匹配内容的类型 默认1
 * @param {Number} index 结果数组的索引
 * @return any
 */
function betweenContent(str, f, l, pattern = 1, index = -1) {
    let meta = '([{}])^$|)?*+.',
        F = meta.includes(f) ? `\${f}` : f,
        L = meta.includes(l) ? `\${l}` : l,
        p1 = '*?',
        p2 = '?',
        p3 = '',
        regStr = `[${F}]${pattern == 2 ? '?' : ''}([^${F + L}]+)[${L}]${pattern == 1 ? p1 : pattern == 2 ? p2 : p3}`,
        reg = new RegExp(regStr, 'gi'),
        result = pattern == 1 ? str.match(reg).map(i => i.substr(1)) : str.match(reg);
    return index == -1 ? result : result[index]
}

//测试用例

betweenContent('1[2①3]4[35②35]35[43③45]345', '[', ']')// ["2①3", "35②35", "43③45"]
betweenContent('1[2①3]4[35②35]35[43③45]345', '[', ']', 1) //["2①3", "35②35", "43③45"]
betweenContent('1[2①3]4[35②35]35[43③45]345', '[', ']', 1,1) //35②35
 
betweenContent('1{2①3}4{35②35}35{43③45}345', '{', '}') //["2①3", "35②35", "43③45"]
betweenContent('1{2①3}4{35②35}35{43③45}345', '{', '}', 1)//["2①3", "35②35", "43③45"]
betweenContent('1{2①3}4{35②35}35{43③45}345', '{', '}', 2)//["1", "{2①3}", "4", "{35②35}", "35", "{43③45}", "345"]
betweenContent('1{2①3}4{35②35}35{43③45}345', '{', '}', 3)//["{2①3}", "{35②35}", "{43③45}"]
betweenContent('1{2①3}4{35②35}35{43③45}345', '{', '}', 1,0)//2①3


betweenContent('1-2①3-4-35②35-35-43③45-345', '-', '-')//["2①3", "4", "35②35", "35", "43③45", "345"]
betweenContent('1-2①3-4-35②35-35-43③45-345', '-', '-', 1)//["2①3", "4", "35②35", "35", "43③45", "345"]
betweenContent('1-2①3-4-35②35-35-43③45-345', '-', '-', 2)//["1-", "2①3-", "4-", "35②35-", "35-", "43③45-", "345"]
betweenContent('1-2①3-4-35②35-35-43③45-345', '-', '-', 3)//["-2①3-", "-35②35-", "-43③45-"]
betweenContent('1-2①3-4-35②35-35-43③45-345', '-', '-', 3,1) //-35②35-

获取字html字符串中的img的地址

function getImgSrc(s) {
    var r=[];
    s.replace(/<img [^>]*src=['"]([^'"]+)[^>]*>/gi, function (m,c) { r.push(c);});
    return r;
}
function getImgSrc(s) {
    let container = document.createElement('div')
    container.innerHTML = s
    return [...container.querySelectorAll('img')].map(i=>i.getAttribute('src'))   
}

//测试用例
let s=
`<p style="white-space: normal;">
<img title="" alt="1.jpg" src="https://lb.yimiyijia.cn/attached/attachment/201812/f7/71/f7f33bd36bfc80118956aaf3817d2d71.jpg_600x2000.jpg"/>
<img title="" alt="2.jpg" src="https://lb.yimiyijia.cn/attached/attachment/201812/d3/da/d3fb189830bb4654a44661ea25d374da.jpg_600x2000.jpg"/>
</p >`;

getImgSrc(s)
//输出：["https://lb.yimiyijia.cn/attached/attachment/201812…f7f33bd36bfc80118956aaf3817d2d71.jpg_600x2000.jpg", "https://lb.yimiyijia.cn/attached/attachment/201812…d3fb189830bb4654a44661ea25d374da.jpg_600x2000.jpg"]

数组 findAllIndexJson 扩展

Array.prototype.findIndexAllJson = function(callback){
    let arr = [];
    for(let i=0;i<this.length;i++){
        if(callback(this[i])) {
            arr.push(i)
        }
    }
    return arr
}
let jsonArr = [{name:'list',age:27},{name:'wangbo',age:28},{name:'zhangsan',age:27}]
jsonArr.findIndexAllJson(item=>item.age==27) // [0, 2]

数组切片 substr 扩展（类似字符串的 substr）

Array.prototype.substr= function(startIndex,len){
    let res = []
    for(let i=0;i<this.length;i++){
        if(i>=startIndex && res.length<len){
            res.push(this[i]) 
        }
    }
    return res
}
let arr = [1,2,3,4,5] 
arr.substr(0,1) // [1]
arr.substr(0,2) // [1,2]
arr.substr(0,3) // [1,2,3]
arr.substr(1,3) // [2,3,4]

数据类型检测

string

function isString(s){
    return typeof(s) === 'string'
}
function isString(s){
    return ({}).toString.call(s).slice(8,-1) === 'String'
}

Boolean

function isBoolean(s){
    return ({}).toString.call(s).slice(8,-1) === 'Boolean'
}
function isBoolean(s){
    return s=== false || s=== true
}

Null

function isNull(s){
    return ({}).toString.call(s).slice(8,-1) === 'Null'
}
function isNull(s){
    return s === null
}

Undefined

function isUndefined(s){
    return ({}).toString.call(s).slice(8,-1) === 'Undefined'
}
function isUndefined(s){
    return s === undefined
}

Number

function isNumber(p){
    try{
        return p.constructor === Number
    }catch(e){
        return false
    }
}
function isNumber(p){
    return typeof p === 'number'
} 

function isNumber(o){//准确  包含NaN
    return Object.prototype.toString.call(o).slice(8,-1) === 'Number'
}
// 测试
[
    {},
    [],
    undefined,
    null,
    123,
    '123',
    Symbol('111'),
    function(){},
    new Date(),
    false,
    /d+/gi,
    NaN
].map(item=>{
    console.log(isNumber(item))
})
//4false true 6false true

Symbol

function isSymbol(s){
    return ({}).toString.call(s).slice(8,-1) === 'Symbol'
}
function isSymbol(s){
    return typeof s === 'symbol'
}

Function

function isFunction(s){
    return ({}).toString.call(s).slice(8,-1) === 'Function'
}
function isFunction(s){
    return typeof s === 'function'
}

Array

/** 
  *第一种  通过try catch 避免 ：
  * Cannot read property 'constructor' of undefined
  * Cannot read property 'constructor' of null
 */ 
function isArray(o){//准确
    try{
        return o.constructor === Array
    }catch(e){
        return false
    }
}

//第二种  isArray 判断
function isArray(o){//准确
    return Array.isArray(o)
}

//第三种  isArray 判断
function isArray(o){//准确
    return o instanceof Array
}

//第四种
function isArray(o){//准确
    return Object.prototype.toString.call(o).slice(8,-1) === 'Array'
}


[
    {},
    [],
    undefined,
    null,
    123,
    '123',
    Symbol('111'),
    function(){},
    new Date(),
    false,
    /d+/gi
].map(item=>{
    console.log(isArray(item))
})
// false true 9false

Date

function isDate(s){
    return ({}).toString.call(s).slice(8,-1) === 'Date'
}

判断对象类型

/** 
  *第一种  通过try catch 避免 ：
  * Cannot read property 'constructor' of undefined
  * Cannot read property 'constructor' of null
 */ 
function isObject(o){ //准确
    try{
        return o.constructor === Object
    }catch(e){
        return false
    }
}

//第二种
function isObject(o){//准确
    return Object.prototype.toString.call(o).slice(8,-1) === 'Object'
}

判断一个值是否为 有效的 数字（不包含NaN），可以是数字字符串，例如 “123"

function idValidNumber(n){
    try{
        return !isNaN(parseFloat(n)) && isFinite(n);
    }catch(e){
        return false
    }
}

判断空对象

function isEmptyObject(o){
    return ({}).toString.call(o).slice(8,-1) === "Object" &&  !Object.keys(o).length
}

判断空数组

function isEmptyArray(o){
      return Array.isArray(o) && !o.length      
}

判断奇数偶数

3 & 1

取整

-3.52 | 0

优雅的 switch

let value = 'a'
      switch (value) {
        case 'a':
          console.log(1)
          break;
        case 'b':
          console.log(2)
          break;
        case 'c':
          console.log(3)
          break;
        case 'd':
          console.log(4)
          break;
      }
      // 修改后
      let obj = {
        'a': () => {
          console.log(1)
        },
        'b': () => {
          console.log(2)
        },
        'c': () => {
          console.log(3)
        },
        'd': () => {
          console.log(4)
        },
      }
      obj['a']()

优雅的 if  switch替代方式

    const actions = new Map([
        [1, ['成功', 'IndexPage']],
        [2, ['失败', 'failPage']],
        [3, ['失败', 'failPage']],
        [4, ['超时', 'timeoutPage']],
        [5, ['系统内部错区', 'errorPage']],
        ['default', ['其他', 'otherPage']]
    ])

    function fun(status) {
        let action = actions.get(status) || actions.get('default')
        console.log(action[0])
        console.log(action[1])
        // go(action[1])//跳页面方法
    }

    fun(3)

    const actions2 = new Map([
        ['guest', () => {
            console.log('guest')
        }],
        ['master', () => {
            console.log('master')
        }],
        ['default', () => {
            console.log('default')
        }],
    ])

    function fun2(identity) {
        let action = actions2.get(`${identity}`) || actions2.get('default')
        action.call(this)
    }

    fun2('master')

获取浏览器放大倍数

    //获取当前页面的缩放值
    function detectZoom() {
      let ratio = 0,
        screen = window.screen,
        ua = navigator.userAgent.toLowerCase();

      if (window.devicePixelRatio !== undefined) {
        ratio = window.devicePixelRatio;
      } else if (~ua.indexOf("msie")) {
        if (screen.deviceXDPI && screen.logicalXDPI) {
          ratio = screen.deviceXDPI / screen.logicalXDPI;
        }
      } else if (
        window.outerWidth !== undefined &&
        window.innerWidth !== undefined
      ) {
        ratio = window.outerWidth / window.innerWidth;
      }

      if (ratio) {
        ratio = Math.round(ratio * 100);
      }
      return ratio;
    }
    $(window).resize(function() {
      console.log(detectZoom());
    });
    // window.addEventListener("resize", () => {
    //   console.log(detectZoom());
    // });

截取视频帧

<button onclick="getCurTime()" type="button">获得当前时间的位置</button>
<button onclick="setCurTime()" type="button">把时间位置设置为 5 秒</button>
<video id="video1" controls="controls">
  <source src="/example/html5/mov_bbb.mp4" type="video/mp4">
  <source src="/example/html5/mov_bbb.ogg" type="video/ogg">
  Your browser does not support HTML5 video.
</video>
<img id='img' style='200px;height:100px'/>
<script>
  myVid = document.getElementById("video1");
  function getCurTime() {
    alert(myVid.currentTime);
  }
  function setCurTime() {
    myVid.currentTime = 5;
  }
  var canvas = document.createElement('canvas');
  var img = document.getElementById('img');
  const video = document.getElementById('video1');
  video.setAttribute('crossOrigin', 'anonymous');
  canvas.width = video.clientWidth;
  canvas.height = video.clientHeight;
  video.currentTime = 0.5
  video.onloadeddata = (() => {
    canvas.getContext('2d').drawImage(video, 0, 0, canvas.width, canvas.height);
    var dataURL = canvas.toDataURL('image/png');
    img.setAttribute('src', dataURL);
  })
</script>

 有些视频第一帧黑屏，可以借用video currentTime将视频指定到一个位置再来进行截图 如第一帧黑屏时可以将视频调到第1秒的位置再进行截图 video.currentTime = 1