1玫霎、需求引入

最近遇到的一個(gè)問題鸽斟，特意寫個(gè)筆記記錄一下酗捌，iview的表格數(shù)據(jù)導(dǎo)出excel文件呢诬，然后去官網(wǎng)翻閱API涌哲，發(fā)現(xiàn)導(dǎo)出的csv后綴的文件,然后官網(wǎng)上明確的說(shuō)明了只支持導(dǎo)出CSV類型的文件，但是公司需求給出的是需要XLSX尚镰，后來(lái)通過查閱資料找到了兩種解決這類問題的方案：1.修改源碼阀圾，添加一個(gè)導(dǎo)出XLSX文件后綴的方法，然后把這個(gè)方法類似于CSV的方法一樣暴露出去 2. 利用Blob.js去解決
我今天使用的是通過Blob.js去處理的狗唉，下面寫下詳細(xì)的解決過程：

1.1初烘、CSV后綴結(jié)尾的文件和XLSX后綴結(jié)尾的文件二者的區(qū)別

csv是文本文件,用記事本就能打開，XLS是二進(jìn)制的文件只有用EXCEL才能打開敞曹。
　　1账月、xls文件就是Microsoft excel電子表格的文件格式。
　　2澳迫、csv是最通用的一種文件格式局齿，它可以非常容易地被導(dǎo)入各種PC表格及數(shù)據(jù)庫(kù)中。 此文件橄登，一行即為數(shù)據(jù)表的一行抓歼。生成數(shù)據(jù)表字段用半角逗號(hào)隔開。

2拢锹、npm 安裝

使用這種解決方法需要一定的插件庫(kù)谣妻，因此，要先打開終端安裝插件

npm install file-saver@1.3.3     用來(lái)保存文件的

npm install --save-dev script-loader   由于由于這幾個(gè)文件不支持import引入卒稳，所以我們需要script-loader來(lái)將他們掛載到全局開發(fā)環(huán)境下面去蹋半。

npm install xlsx   指的是 js-xlsx

npm install jszip  壓縮文件

3、在src目錄下創(chuàng)建一個(gè)公共的js文件夾

我是在src目錄下新建了一個(gè)叫vendor的文件夾充坑，這里面將要放幾個(gè)封裝好的插件（詳細(xì)了解的話可以查閱官網(wǎng)文檔）
首先减江，先創(chuàng)建第一個(gè)js文件Blob.js

3.1、Blob.js

blob的存在捻爷，允許我們可以通過js直接操作二進(jìn)制數(shù)據(jù)辈灼。

//Blog.js官網(wǎng)的，用來(lái)轉(zhuǎn)二進(jìn)制的也榄。
(function(view) {
    "use strict";

    view.URL = view.URL || view.webkitURL;

    if (view.Blob && view.URL) {
        try {
            new Blob;
            return;
        } catch (e) {}
    }

    // Internally we use a BlobBuilder implementation to base Blob off of
    // in order to support older browsers that only have BlobBuilder
    var BlobBuilder = view.BlobBuilder || view.WebKitBlobBuilder || view.MozBlobBuilder || (function(view) {
        var
            get_class = function(object) {
                return Object.prototype.toString.call(object).match(/^\[object\s(.*)\]$/)[1];
            },
            FakeBlobBuilder = function BlobBuilder() {
                this.data = [];
            },
            FakeBlob = function Blob(data, type, encoding) {
                this.data = data;
                this.size = data.length;
                this.type = type;
                this.encoding = encoding;
            },
            FBB_proto = FakeBlobBuilder.prototype,
            FB_proto = FakeBlob.prototype,
            FileReaderSync = view.FileReaderSync,
            FileException = function(type) {
                this.code = this[this.name = type];
            },
            file_ex_codes = (
                "NOT_FOUND_ERR SECURITY_ERR ABORT_ERR NOT_READABLE_ERR ENCODING_ERR " +
                "NO_MODIFICATION_ALLOWED_ERR INVALID_STATE_ERR SYNTAX_ERR"
            ).split(" "),
            file_ex_code = file_ex_codes.length,
            real_URL = view.URL || view.webkitURL || view,
            real_create_object_URL = real_URL.createObjectURL,
            real_revoke_object_URL = real_URL.revokeObjectURL,
            URL = real_URL,
            btoa = view.btoa,
            atob = view.atob

        , ArrayBuffer = view.ArrayBuffer, Uint8Array = view.Uint8Array;
        FakeBlob.fake = FB_proto.fake = true;
        while (file_ex_code--) {
            FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
        }
        if (!real_URL.createObjectURL) {
            URL = view.URL = {};
        }
        URL.createObjectURL = function(blob) {
            var
                type = blob.type,
                data_URI_header;
            if (type === null) {
                type = "application/octet-stream";
            }
            if (blob instanceof FakeBlob) {
                data_URI_header = "data:" + type;
                if (blob.encoding === "base64") {
                    return data_URI_header + ";base64," + blob.data;
                } else if (blob.encoding === "URI") {
                    return data_URI_header + "," + decodeURIComponent(blob.data);
                }
                if (btoa) {
                    return data_URI_header + ";base64," + btoa(blob.data);
                } else {
                    return data_URI_header + "," + encodeURIComponent(blob.data);
                }
            } else if (real_create_object_URL) {
                return real_create_object_URL.call(real_URL, blob);
            }
        };
        URL.revokeObjectURL = function(object_URL) {
            if (object_URL.substring(0, 5) !== "data:" && real_revoke_object_URL) {
                real_revoke_object_URL.call(real_URL, object_URL);
            }
        };
        FBB_proto.append = function(data /*, endings*/ ) {
            var bb = this.data;
            // decode data to a binary string
            if (Uint8Array && (data instanceof ArrayBuffer || data instanceof Uint8Array)) {
                var
                    str = "",
                    buf = new Uint8Array(data),
                    i = 0,
                    buf_len = buf.length;
                for (; i < buf_len; i++) {
                    str += String.fromCharCode(buf[i]);
                }
                bb.push(str);
            } else if (get_class(data) === "Blob" || get_class(data) === "File") {
                if (FileReaderSync) {
                    var fr = new FileReaderSync;
                    bb.push(fr.readAsBinaryString(data));
                } else {
                    // async FileReader won't work as BlobBuilder is sync
                    throw new FileException("NOT_READABLE_ERR");
                }
            } else if (data instanceof FakeBlob) {
                if (data.encoding === "base64" && atob) {
                    bb.push(atob(data.data));
                } else if (data.encoding === "URI") {
                    bb.push(decodeURIComponent(data.data));
                } else if (data.encoding === "raw") {
                    bb.push(data.data);
                }
            } else {
                if (typeof data !== "string") {
                    data += ""; // convert unsupported types to strings
                }
                // decode UTF-16 to binary string
                bb.push(unescape(encodeURIComponent(data)));
            }
        };
        FBB_proto.getBlob = function(type) {
            if (!arguments.length) {
                type = null;
            }
            return new FakeBlob(this.data.join(""), type, "raw");
        };
        FBB_proto.toString = function() {
            return "[object BlobBuilder]";
        };
        FB_proto.slice = function(start, end, type) {
            var args = arguments.length;
            if (args < 3) {
                type = null;
            }
            return new FakeBlob(
                this.data.slice(start, args > 1 ? end : this.data.length), type, this.encoding
            );
        };
        FB_proto.toString = function() {
            return "[object Blob]";
        };
        FB_proto.close = function() {
            this.size = this.data.length = 0;
        };
        return FakeBlobBuilder;
    }(view));

    view.Blob = function Blob(blobParts, options) {
        var type = options ? (options.type || "") : "";
        var builder = new BlobBuilder();
        if (blobParts) {
            for (var i = 0, len = blobParts.length; i < len; i++) {
                builder.append(blobParts[i]);
            }
        }
        return builder.getBlob(type);
    };
}(typeof self !== "undefined" && self || typeof window !== "undefined" && window || this.content || this));

3.2巡莹、Export2Excel.js

主要是處理好數(shù)據(jù)并且暴露了兩個(gè)接口export_table_to_excel和export_json_to_excel,我們常用export_json_to_excel因?yàn)楦拥目煽匾稽c(diǎn)，我們可以自由的處理數(shù)據(jù)甜紫。

/* eslint-disable */
require('script-loader!file-saver');
require('script-loader!@/vendor/Blob');
import XLSX from 'xlsx'

function generateArray(table) {
    var out = [];
    var rows = table.querySelectorAll('tr');
    var ranges = [];
    for (var R = 0; R < rows.length; ++R) {
        var outRow = [];
        var row = rows[R];
        var columns = row.querySelectorAll('td');
        for (var C = 0; C < columns.length; ++C) {
            var cell = columns[C];
            var colspan = cell.getAttribute('colspan');
            var rowspan = cell.getAttribute('rowspan');
            var cellValue = cell.innerText;
            if (cellValue !== "" && cellValue == +cellValue) cellValue = +cellValue;

            //Skip ranges
            ranges.forEach(function(range) {
                if (R >= range.s.r && R <= range.e.r && outRow.length >= range.s.c && outRow.length <= range.e.c) {
                    for (var i = 0; i <= range.e.c - range.s.c; ++i) outRow.push(null);
                }
            });

            //Handle Row Span
            if (rowspan || colspan) {
                rowspan = rowspan || 1;
                colspan = colspan || 1;
                ranges.push({ s: { r: R, c: outRow.length }, e: { r: R + rowspan - 1, c: outRow.length + colspan - 1 } });
            };

            //Handle Value
            outRow.push(cellValue !== "" ? cellValue : null);

            //Handle Colspan
            if (colspan)
                for (var k = 0; k < colspan - 1; ++k) outRow.push(null);
        }
        out.push(outRow);
    }
    return [out, ranges];
};

function datenum(v, date1904) {
    if (date1904) v += 1462;
    var epoch = Date.parse(v);
    return (epoch - new Date(Date.UTC(1899, 11, 30))) / (24 * 60 * 60 * 1000);
}

function sheet_from_array_of_arrays(data, opts) {
    var ws = {};
    var range = { s: { c: 10000000, r: 10000000 }, e: { c: 0, r: 0 } };
    for (var R = 0; R != data.length; ++R) {
        for (var C = 0; C != data[R].length; ++C) {
            if (range.s.r > R) range.s.r = R;
            if (range.s.c > C) range.s.c = C;
            if (range.e.r < R) range.e.r = R;
            if (range.e.c < C) range.e.c = C;
            var cell = { v: data[R][C] };
            if (cell.v == null) continue;
            var cell_ref = XLSX.utils.encode_cell({ c: C, r: R });

            if (typeof cell.v === 'number') cell.t = 'n';
            else if (typeof cell.v === 'boolean') cell.t = 'b';
            else if (cell.v instanceof Date) {
                cell.t = 'n';
                cell.z = XLSX.SSF._table[14];
                cell.v = datenum(cell.v);
            } else cell.t = 's';

            ws[cell_ref] = cell;
        }
    }
    if (range.s.c < 10000000) ws['!ref'] = XLSX.utils.encode_range(range);
    return ws;
}

function Workbook() {
    if (!(this instanceof Workbook)) return new Workbook();
    this.SheetNames = [];
    this.Sheets = {};
}

function s2ab(s) {
    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;
}

export function export_table_to_excel(id) {
    var theTable = document.getElementById(id);
    var oo = generateArray(theTable);
    var ranges = oo[1];

    /* original data */
    var data = oo[0];
    var ws_name = "SheetJS";

    var wb = new Workbook(),
        ws = sheet_from_array_of_arrays(data);

    /* add ranges to worksheet */
    // ws['!cols'] = ['apple', 'banan'];
    ws['!merges'] = ranges;

    /* add worksheet to workbook */
    wb.SheetNames.push(ws_name);
    wb.Sheets[ws_name] = ws;

    var wbout = XLSX.write(wb, { bookType: 'xlsx', bookSST: false, type: 'binary' });

    saveAs(new Blob([s2ab(wbout)], { type: "application/octet-stream" }), "test.xlsx")
}

export function export_json_to_excel({ header, data, filename = 'excel-list', autoWidth = true } = {}) {
    /* original data */
    data = [...data]
    data.unshift(header);
    var ws_name = "SheetJS";
    var wb = new Workbook(),
        ws = sheet_from_array_of_arrays(data);

    if (autoWidth) {
        /*設(shè)置worksheet每列的最大寬度*/
        const colWidth = data.map(row => row.map(val => {
                /*先判斷是否為null/undefined*/
                if (val == null) {
                    return { 'wch': 10 };
                }
                /*再判斷是否為中文*/
                else if (val.toString().charCodeAt(0) > 255) {
                    return { 'wch': val.toString().length * 2 };
                } else {
                    return { 'wch': val.toString().length };
                }
            }))
            /*以第一行為初始值*/
        let result = colWidth[0];
        for (let i = 1; i < colWidth.length; i++) {
            for (let j = 0; j < colWidth[i].length; j++) {
                if (result[j]['wch'] < colWidth[i][j]['wch']) {
                    result[j]['wch'] = colWidth[i][j]['wch'];
                }
            }
        }
        ws['!cols'] = result;
    }

    /* add worksheet to workbook */
    wb.SheetNames.push(ws_name);
    wb.Sheets[ws_name] = ws;

    var wbout = XLSX.write(wb, { bookType: 'xlsx', bookSST: false, type: 'binary' });
    saveAs(new Blob([s2ab(wbout)], { type: "application/octet-stream" }), filename + ".xlsx");
}

3.3降宅、Export2Zip.js

暴漏出export_txt_to_zip這個(gè)接口，用來(lái)導(dǎo)出壓縮文件的

/* eslint-disable */
require('script-loader!file-saver');
import JSZip from 'jszip'

export function export_txt_to_zip(th, jsonData, txtName, zipName) {
  const zip = new JSZip()
  const txt_name = txtName || 'file'
  const zip_name = zipName || 'file'
  const data = jsonData
  let txtData = `${th}\r\n`
  data.forEach((row) => {
    let tempStr = ''
    tempStr = row.toString()
    txtData += `${tempStr}\r\n`
  })
  zip.file(`${txt_name}.txt`, txtData)
  zip.generateAsync({type:"blob"}).then((blob) => {
    saveAs(blob, `${zip_name}.zip`)
  }, (err) => {
    alert('導(dǎo)出失敗')
  })
}

4囚霸、開始導(dǎo)出

4.1腰根、首先我們要?jiǎng)?chuàng)建一個(gè)導(dǎo)出的按鈕

我這里使用的是iview組件的

<Button type="primary" @click="exportData()">
      <Icon type="ios-download-outline"></Icon> 
            導(dǎo)出excel
</Button>

4.2、調(diào)取后臺(tái)接口拿到后臺(tái)的數(shù)據(jù)

我這里的后臺(tái)數(shù)據(jù)datalist這個(gè)數(shù)組數(shù)據(jù)邮辽，這個(gè)根據(jù)自身需求情況來(lái)

getData(pn) {
      getLoglist(pn, this.ps, this.time_begin, this.time_end).then((res) => {
        this.datalist = res.data.records;
        this.totla = res.data.total;
      });
    }

4.3唠雕、在data選項(xiàng)中定義變量

listLoading: true,
downloadLoading: false,
filename: "系統(tǒng)日志",  //這個(gè)是我的文件導(dǎo)出的名稱
datalist: [],

4.4贸营、在方法中開始處理導(dǎo)出

//導(dǎo)出.xlsx文件
    exportData() {
      import("@/vendor/Export2Excel").then((excel) => {
        //表格的表頭列表
        const tHeader = [
          "creator",
          "roleName",
          "createTime",
          "ipAddr",
          "description",
        ];
        //相對(duì)應(yīng)的數(shù)據(jù)中的字段
        const filterVal = [
          "creator",
          "roleName",
          "createTime",
          "ipAddr",
          "description",
        ];
        const list = this.datalist;
        const data = this.formatJson(filterVal, list);
        excel.export_json_to_excel({
          header: tHeader,
          data,
          filename: this.filename,
        });
        this.downloadLoading = false;
      });
    },
    formatJson(filterVal, jsonData) {
      return jsonData.map((v) =>
        filterVal.map((j) => {
          return v[j];
        })
      );
    },

4.5、注意事項(xiàng)

切記要在formatJson傳參的時(shí)候?qū)⒑笈_(tái)數(shù)據(jù)(需要處理的數(shù)據(jù))傳入岩睁，否則是無(wú)法導(dǎo)出的钞脂，或者會(huì)出現(xiàn)報(bào)錯(cuò)。

5捕儒、效果展示

image.png