参考：https://www.cnblogs.com/zhaopanpan/p/9927548.html

单文件上传

html

<blockquote class="layui-elem-quote layui-quote-nm" style="margin-top: 10px;">
                        <div id="uploadQRcode" class="layui-upload">
                        <button type="button" class="layui-btn" id="uploadQR">
                            <i class="layui-icon">&#xe67c;</i>上传客服二维码<span style="color: red;font-size: 20px;">*</span>
                        </button>
                        <div class="layui-upload-list">
                            <img id="qrshow" src="" alt="" class="layui-upload-img"
                                 style="height: 100px;width:100px;border:1px solid black;">
                        </div>
                        <div id="startDiv">
                            <button type="button" class="layui-btn" id="startUploadQR">开始上传</button>
                        </div>
                            <div style="color: #c2c2c2;margin:10px 0;">温馨提示: 每次最多上传一张图片, 单张图片的大小不超过2MB</div>
                    </div>
                    <input type="text" name="cli_qrcode" id="qrInput" style="display: none;" lay-verify="required">
</blockquote>

js

layui.use(['form', 'element', 'upload'], function () {
        var form = layui.form;
        var element = layui.element;
        var $ = layui.jquery;
        var upload = layui.upload;

        //单文件示例  选完文件后不自动上传
        var uploadSingle = upload.render({
            elem: '#uploadQR'
            , url: '/web/api/upload/upload?option=4'
            , accept: 'images'  // 允许上传的文件类型
            , size: 2048        // 最大允许上传的文件大小  单位 KB
            , auto: false
            , bindAction: '#startUploadQR'
            , choose: function (obj) {
                //预读本地文件示例，不支持ie8
                obj.preview(function (index, file, result) {
                    $('#qrshow').attr('src', result); //图片链接（base64）
                });
            }
            , done: function (res, index, upload) {
                if (res.code == 0) {
                    //上传成功
                    $("#qrInput").val(res.data[0].fp_relative);
                    var startDiv = $('#startDiv');
                    startDiv.html('<span style="color: #5FB878;">上传成功</span>');
                } else {
                    this.error(index, upload);
                }
            }
            , error: function (index, upload) {
                //演示失败状态，并实现重传
                var startDiv = $('#startDiv');
                startDiv.html('<span style="color: #FF5722;">上传失败</span> <a class="layui-btn layui-btn-xs demo-reload" style="width:50px;height:30px;text-align:center;line-height:30px;">重试</a>');
                startDiv.find('.demo-reload').on('click', function () {
                    uploadSingle.upload();
                });
            }
        });
    });

多文件上传

html

<blockquote class="layui-elem-quote layui-quote-nm" style="margin-top: 10px;">
                        <div id="uploadImg" class="layui-upload">
                        <button type="button" class="layui-btn" id="upload">
                            <i class="layui-icon">&#xe67c;</i>上传商铺图片<span style="color: red;font-size: 20px;">*</span>
                        </button>
                        <div class="layui-upload-list">
                            <table class="layui-table" style="text-align: center;">
                                <thead>
                                <tr>
                                    <th style="text-align: center;">图片预览</th>
                                    <th style="text-align: center;">大小</th>
                                    <th style="text-align: center;">状态</th>
                                    <th style="text-align: center;">操作</th>
                                </tr>
                                </thead>
                                <tbody id="imgList"></tbody>
                            </table>
                        </div>
                        <button type="button" class="layui-btn" id="startUpload">开始上传</button>
                            <div style="color: #c2c2c2;margin:10px 0;">温馨提示: 每次最多上传六张图片, 单张图片的大小不超过5MB, 长宽比例推荐1.5:1,
                                推荐上传图片长675px,宽450px
                            </div>
                    </div>
                    <input type="text" name="face_img" id="imgInput" style="display: none;" lay-verify="required">
</blockquote>

js

layui.use(['table', 'form', 'element', 'upload'], function () {
        var table = layui.table;
        var form = layui.form;
        var element = layui.element;
        var $ = layui.jquery;
        var upload = layui.upload;
        
        //多文件列表示例
        var demoListView = $('#imgList');
        var totalArray = new Array();
        var uploadInst = upload.render({
            elem: '#upload' //绑定元素
            , url: '/web/api/upload/upload?option=3' //上传接口
            , accept: 'images'  // 允许上传的文件类型
            // , acceptMime: 'image/jpg,image/png'   // (只支持jpg和png格式，多个用逗号隔开),
            , size: 5120        // 最大允许上传的文件大小  单位 KB
            , auto: false //选择文件后不自动上传
            , bindAction: '#startUpload' //指向一个按钮触发上传
            , multiple: true   // 开启多文件上传
            , number: 6    //  同时上传文件的最大个数
            , choose: function (obj) {
                var files = this.files = obj.pushFile(); //将每次选择的文件追加到文件队列
                var arr = Object.keys(files);
                totalArray = totalArray.concat(arr);
                // 检查上传文件的个数
                if (totalArray.length <= 6) {
                    //读取本地文件
                    obj.preview(function (index, file, result) {
                        var tr = $(['<tr id="upload-' + index + '">'
                            , '<td><img src="' + result + '" alt="' + file.name + '" class="layui-upload-img" style="height: 66px;width:100px;"></td>'
                            , '<td>' + (file.size / 1014).toFixed(1) + 'kb</td>'
                            , '<td>等待上传</td>'
                            , '<td>'
                            , '<button class="layui-btn demo-reload layui-hide">重传</button>'
                            , '<button class="layui-btn layui-btn-danger demo-delete">删除</button>'
                            , '</td>'
                            , '</tr>'].join(''));

                        //单个重传
                        tr.find('.demo-reload').on('click', function () {
                            obj.upload(index, file);
                        });

                        //删除
                        tr.find('.demo-delete').on('click', function () {
                            delete files[index]; //删除对应的文件
                            tr.remove();
                            uploadListIns.config.elem.next()[0].value = ''; //清空 input file 值，以免删除后出现同名文件不可选
                        });

                        demoListView.append(tr);
                    });
                } else {
                    // 超出上传最大文件
                    layer.msg("上传文件最大不超过6个")
                }

            }
            , done: function (res, index, upload) {
                console.log("res", res);
                if (res.code == 0) { //上传成功
                    // 上传成功后将图片路径拼接到input中，多个路径用","分割
                    var inputVal = document.getElementById("imgInput").value;
                    var valData = "";
                    if (inputVal) {
                        valData = inputVal + "," + res.data[0].fp_relative;
                    } else {
                        valData = res.data[0].fp_relative;
                    }
                    document.getElementById("imgInput").value = valData;
                    var tr = demoListView.find('tr#upload-' + index)
                        , tds = tr.children();
                    tds.eq(2).html('<span style="color: #5FB878;">上传成功</span>');
                    tds.eq(3).html(''); //清空操作
                    return delete this.files[index]; //删除文件队列已经上传成功的文件

                }
                this.error(index, upload);
            }
            , error: function (index, upload) {
                var tr = demoListView.find('tr#upload-' + index)
                    , tds = tr.children();
                tds.eq(2).html('<span style="color: #FF5722;">上传失败</span>');
                tds.eq(3).find('.demo-reload').removeClass('layui-hide'); //显示重传
            }
        });
    });