在fastadmin的文档中，数据库和组件–》文件上传部分介绍了文件和图片的上传，但是实际操作之后发现字段后缀改成file，文件大小限制修改之后，依然不能进行视频上传，始终报错文件格式受限制的问题，这里记录一下解决方法

1.首先找到你的html文件，在生成的源代码上添加2个属性data-mimetype和data-maxsize，这2个属性文档中有介绍

<div class="form-group">
        <label class="control-label col-xs-12 col-sm-2">{:__('Vediofile')}:</label>
        <div class="col-xs-12 col-sm-8">
            <div class="input-group">
                <input id="c-vediofile" class="form-control" size="50" name="row[vediofile]" type="text">
                <div class="input-group-addon no-border no-padding">
                    <span><button type="button" id="plupload-vediofile" class="btn btn-danger plupload" data-input-id="c-vediofile" data-mimetype="mp4,mp3,avi,flv,wmv" data-multiple="false" data-maxsize="1024M"><i class="fa fa-upload"></i> {:__('Upload')}</button></span>
                    <span><button type="button" id="fachoose-vediofile" class="btn btn-primary fachoose" data-input-id="c-vediofile" data-mimetype="mp4,mp3,avi,flv,wmv" data-multiple="false"><i class="fa fa-list"></i> {:__('Choose')}</button></span>
                </div>
                <span class="msg-box n-right" for="c-vediofile"></span>
            </div>

        </div>
    </div>

2.找到文件上传的php，在application/admin/controller/Ajax.php，修改里面的upload方法，在此基础上添加视频上传的代码即可

/**
     * 上传文件
     */
    public function upload()
    {
        //dump(123);die;
        Config::set('default_return_type', 'json');
        $file = $this->request->file('file');
        if (empty($file)) {
            $this->error(__('No file upload or server upload limit exceeded'));
        }
        //判断是否已经存在附件
        $sha1 = $file->hash();
        $upload = Config::get('upload');
        preg_match('/(\d+)(\w+)/', $upload['maxsize'], $matches);
        $type = strtolower($matches[2]);
        $typeDict = ['b' => 0, 'k' => 1, 'kb' => 1, 'm' => 2, 'mb' => 2, 'gb' => 3, 'g' => 3];
        $size = (int)$upload['maxsize'] * pow(1024, isset($typeDict[$type]) ? $typeDict[$type] : 0);
        $fileInfo = $file->getInfo();
        $suffix = strtolower(pathinfo($fileInfo['name'], PATHINFO_EXTENSION));
        $suffix = $suffix ? $suffix : 'file';
        $mimetypeArr = explode(',', strtolower($upload['mimetype']));
        $mimetypeArr=array_merge($mimetypeArr,['mp4','mp3','avi','flv','wmv']);
        $typeArr = explode('/', $fileInfo['type']);
        //验证文件后缀
        if ($upload['mimetype'] !== '*' &&
            (
                !in_array($suffix, $mimetypeArr)
                || (stripos($typeArr[0] . '/', $upload['mimetype']) !== false && (!in_array($fileInfo['type'], $mimetypeArr) && !in_array($typeArr[0] . '/*', $mimetypeArr)))
            )
        ) {
            //dump(123456);die;
            $this->error(__('Uploaded file format is limited'));
        }
        $replaceArr = [
            '{year}'     => date("Y"),
            '{mon}'      => date("m"),
            '{day}'      => date("d"),
            '{hour}'     => date("H"),
            '{min}'      => date("i"),
            '{sec}'      => date("s"),
            '{random}'   => Random::alnum(16),
            '{random32}' => Random::alnum(32),
            '{filename}' => $suffix ? substr($fileInfo['name'], 0, strripos($fileInfo['name'], '.')) : $fileInfo['name'],
            '{suffix}'   => $suffix,
            '{.suffix}'  => $suffix ? '.' . $suffix : '',
            '{filemd5}'  => md5_file($fileInfo['tmp_name']),
        ];
        $savekey = $upload['savekey'];
        $savekey = str_replace(array_keys($replaceArr), array_values($replaceArr), $savekey);

        $uploadDir = substr($savekey, 0, strripos($savekey, '/') + 1);
        $fileName = substr($savekey, strripos($savekey, '/') + 1);
        $splInfo = $file->validate(['size' => $size])->move(ROOT_PATH . '/public' . $uploadDir, $fileName);
        if ($splInfo) {
            $imagewidth = $imageheight = 0;
            if (in_array($suffix, ['gif', 'jpg', 'jpeg', 'bmp', 'png', 'swf', 'mp4', 'mp3'])) {
                $imgInfo = getimagesize($splInfo->getPathname());
                $imagewidth = isset($imgInfo[0]) ? $imgInfo[0] : $imagewidth;
                $imageheight = isset($imgInfo[1]) ? $imgInfo[1] : $imageheight;
            }
            $params = array(
                'admin_id'    => (int)$this->auth->id,
                'user_id'     => 0,
                'filesize'    => $fileInfo['size'],
                'imagewidth'  => $imagewidth,
                'imageheight' => $imageheight,
                'imagetype'   => $suffix,
                'imageframes' => 0,
                'mimetype'    => $fileInfo['type'],
                'url'         => $uploadDir . $splInfo->getSaveName(),
                'uploadtime'  => time(),
                'storage'     => 'local',
                'sha1'        => $sha1,
            );
            $attachment = model("attachment");
            $attachment->data(array_filter($params));
            $attachment->save();
            \think\Hook::listen("upload_after", $attachment);
            $this->success(__('Upload successful'), null, [
                'url' => $uploadDir . $splInfo->getSaveName()
            ]);
        } else {
            // 上传失败获取错误信息
            $this->error($file->getError());
        }
    }

3.这些修改好之后，如果出现上传文件或者图片上传4-5个之后就会报错，可以查看自己的数据库，在创建数据库字段的时候，文件和图片的字段类型是varchar，fastadmin才能生成对应的上传文件和图片，但是多图和多文件上传的时候，你会发现这字段类型完全不够用，这时需要我们手动修改对应字段类型为text，不需要重新生成一遍后台，问题解决。