通过Buzz \ Browser发送文件

Question

我正在使用Symfony和Buzz \ Browser供应商，我需要通过POST将文件发送到我的Slack频道。这是我应该调用的Slack方法：Slack file upload

这是我的代码：

public function uploadFile(array $channels, File $file, $initial_comment = '', $title = '') {
    $channels = implode(',', $channels);
    $headers['Content-Type'] = 'multipart/form-data';
    $content = json_encode(array(
        'channels' => $channels,
        'file' => new FormUpload($file->getPathname()),
        'filename' => $file->getFilename(),
        'filetype' => $file->getExtension(),
        'initial_comment' => $initial_comment,
        'title' => $title
    ));
    return $this->post('/files.upload', $headers, $content);
}

发布方法：

public function post($endpoint, $headers = array(), $content = '') {
    $headers['Authorization'] = sprintf('Bearer %s', $this->getToken());

    return $this->browser->post($this->url . $endpoint, $headers, $content);
}

我收到响应错误消息：invalid_form_data

修改

我找到了这个解决方案：How to send file data as post parameter in BuzzBrowser post call

并且工作正常，但有没有办法通过Buzz的post方法发送文件？