handleDownClick(){

      // 模拟数据

      var data = [

        {'时间':'2020-01-12','新注册人数':'12','在线人数':'12','累计用户数':'12'},

        {'时间':'2020-01-12','新注册人数':'12','在线人数':'12','累计用户数':'13'},

        {'时间':'2020-01-12','新注册人数':'12','在线人数':'12','累计用户数':'14'},

        {'时间':'2020-01-12','新注册人数':'12','在线人数':'12','累计用户数':'15'},

      ];

      //表格标题

      var dataTitle = '用户统计2020-01-10-2020-01-12';

      // 配置文件类型

        const wopts = { bookType: 'xlsx', bookSST: true, type: 'binary', cellStyles: true };

        this.downloadExl(data, wopts, dataTitle)

    },

    // 下载功能

     saveAs(obj, fileName) {

          var tmpa = document.createElement("a");

          tmpa.download = fileName || "未命名";

          // 兼容ie

          if ("msSaveOrOpenBlob" in navigator) {

            window.navigator.msSaveOrOpenBlob(obj, "下载的文件名"+ ".xlsx");

          } else {

            tmpa.href = URL.createObjectURL(obj);

          }

          tmpa.click();

          setTimeout(function() {

            URL.revokeObjectURL(obj);

          }, 100);

    },

    downloadExl(json, type, dataTitle) {

        var tmpdata = json[0];

        json.unshift({});

        var keyMap = []; //获取keys

        for (var k in tmpdata) {

            keyMap.push(k);

            json[0][k] = k;

        }

        var tmpdata = [];//用来保存转换好的json

        json.map((v, i) => {

          let data = keyMap.map((k, j) => {

            // console.log(k,this.getCharCol(j));

            return Object.assign({}, {

              v: v[k],

              position: (j > 25 ? this.getCharCol(j) : String.fromCharCode(65 + j)) + (i + 2)

            });

          });

        return data;

        }).reduce((prev, next) => prev.concat(next)).forEach((v, i) => tmpdata[v.position] = {

            v: v.v

        });

        var outputPos = Object.keys(tmpdata); //设置区域,比如表格从A1到D10

        tmpdata["A1"] = {v:dataTitle};

        outputPos = ["A1"].concat(outputPos);

        tmpdata["A1"].s = { font: { sz: 14, bold: true, vertAlign:true }, alignment:{ vertical:"center", horizontal:"center" }, fill: { bgColor: { rgb: "E8E8E8"}, fgColor: { rgb: "E8E8E8" } } };//<====设置xlsx单元格样式

        tmpdata["!merges"] = [{

            s: { c: 0, r: 0 },

            e: { c: 3, r: 0 }

        }];//<====合并单元格 

        tmpdata["!cols"] = [

          {wpx: 300},

          {wpx: 300},

          {wpx: 300},

          {wpx: 300}

        ];//<====设置一列宽度 

        var tmpWB = {

            SheetNames: ['mySheet'], //保存的表标题

            Sheets: {

              'mySheet': Object.assign({},

              tmpdata, //内容

              {

                '!ref': outputPos[0] + ':' + outputPos[outputPos.length - 1] //设置填充区域

              }

              )

            }

        };

        var tmpDown = new Blob([this.s2ab(XLSX.write(tmpWB,

            { bookType: (type == undefined ? 'xlsx' : type.bookType), bookSST: false, type: 'binary' }//这里的数据是用来定义导出的格式类型

        ))], {

                type: ""

            });

        this.saveAs(tmpDown, "下载的文件名" + '.' + (type.bookType == "biff2" ? "xls" : type.bookType));

    },

    // 获取26个英文字母用来表示excel的列

    getCharCol(n) {

        let temCol = '',

            s = '',

            m = 0

        while (n > 0) {

            m = n % 26 + 1

            s = String.fromCharCode(m + 64) + s

            n = (n - m) / 26

        }

        return s

    },

    s2ab(s) {

        if (typeof ArrayBuffer !== 'undefined') {

            var buf = new ArrayBuffer(s.length);

            var view = new Uint8Array(buf);

            for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;

            return buf;

        } else {

            var buf = new Array(s.length);

            for (var i = 0; i != s.length; ++i) buf[i] = s.charCodeAt(i) & 0xFF;

            return buf;

        }

    },