//导入
       fileUpload() {
            let object = this;
            let file = $('#file')[0].files[0];
            var formData = new FormData();
            formData.append("file", file);//将文件塞入FormDat
            //替换掉页面标签，重新绑定事件
            $('#file').replaceWith('<input type="file" id="file">');
            $('#file').on('change', function () {
                object.fileUpload();
            });
            $.ajax({
                url: "www",
                type: "POST",
                data: formData,
                async: false,
                processData: false,  // 告诉jQuery不要去处理发送的数据
                contentType: false,   // 告诉jQuery不要去设置Content-Type请求头
                success: (data) => {
                   
                },
                error: () => {
                    
                }
            });
        },

<span>导入</span>
<input type="file" id="file" @change="fileUpload()">