PHP curl 模拟表单数据流multipart/form-data上传文件

在调用公众号接口https://api.weixin.qq.com/cgi-bin/material/add_material?access_token=".$token."&type=".$type;

上传永久素材文件总是返回"{\"errcode\":41005,\"errmsg\":\"media data missing\"}"

经过多次测试使用下面的方式，可以正常上传

//调用测试

protected static $url;

protected static $delimiter;

protected static $instance;

public function index()

{

        static::$delimiter = uniqid();

$basename = Request::instance()->root();

if (pathinfo($basename, PATHINFO_EXTENSION) == 'php') {

    $basename = dirname($basename);

}

        $result=$this->wxAddMaterial($token,$basename.'/upload/images/gnlog.jpg','image');

    }

// 新增其他类型永久素材

public function wxAddMaterial($token,$filename='',$type='') {

    // 设置请求参数

    static::$url = "https://api.weixin.qq.com/cgi-bin/material/add_material?access_token=".$token."&type=".$type;

    $filePath = str_replace('\\', '/', $filename);

    // 发送请求

    $imginfo=pathinfo($filePath);

    $fields = array(

        'media'=>file_get_contents(".".$filePath),

        'filename'=>$imginfo["basename"],

);

    $res = $this->putPart( $fields);

    // 发送请求

    return $res;

}

//推送文件流

public function putPart($param) {

    $post_data = static::buildData($param);

    $curl = curl_init(static::$url);

    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

    curl_setopt($curl, CURLOPT_POST, true);

    curl_setopt($curl, CURLOPT_POSTFIELDS, $post_data);

    curl_setopt($curl, CURLOPT_HTTPHEADER, [

        "Content-Type: multipart/form-data; boundary=" . static::$delimiter,

        "Content-Length: " . strlen($post_data)

]);

    $response = curl_exec($curl);

    curl_close($curl);

    return $response;

}

//编译请求头格式和数据流

private static function buildData($param){

    $data = '';

    $eol = "\r\n";

    $upload = $param['media'];

    unset($param['media']);

    foreach ($param as $name => $content) {

        $data .= "--" . static::$delimiter . "\r\n"

            . 'Content-Disposition: form-data; name="' . $name . "\"\r\n\r\n"

            . $content . "\r\n";

}

    $data .= "--" . static::$delimiter . $eol

        . 'Content-Disposition: form-data; name="media"; filename="' . $param['filename'] . '"' . "\r\n"

        . 'Content-Type:application/octet-stream'."\r\n\r\n";

    $data .= $upload . "\r\n";

    $data .= "--" . static::$delimiter . "--\r\n";

    return $data;

}

根据自己的实际情况稍作修改