<div class="filebox">

    <el-upload class="upload-demo" :action="url" :on-preview="handlePreview" :on-remove="handleRemove" 
　　　　　　multiple :limit="limitnum" :on-exceed="handleExceed" :file-list="fileList" :beforeUpload="beforeAvatarUpload">

    <el-button size="mini" type="primary">点击上传</el-button>

    <div slot="tip" class="el-upload__tip">只能上传jpg/png文件，且不超过500kb</div>

    </el-upload>

</div>

　　　　　　beforeAvatarUpload(file) {

                var testmsg=file.name.substring(file.name.lastIndexOf('.')+1)

                const extension = testmsg === 'xls'

                const extension2 = testmsg === 'xlsx'

                const isLt2M = file.size / 1024 / 1024 < 10

                if(!extension && !extension2) {

                    this.$message({

                        message: '上传文件只能是 xls、xlsx格式!',

                        type: 'warning'

                    });

                }

                if(!isLt2M) {

                    this.$message({

                        message: '上传文件大小不能超过 10MB!',

                        type: 'warning'

                    });

                }

                return extension || extension2 && isLt2M

            }