php curl post 多维数组

function SendDataByCurl($url,$data=array()){
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL, "$url");
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
  curl_setopt($ch, CURLOPT_HEADER, 0);
  curl_setopt($ch,CURLOPT_TIMEOUT,3); 
   // POST数据
  curl_setopt($ch, CURLOPT_POST, 1);
  // 把post的变量加上
  curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));  //！！！！！！！！！！！！！！
  //执行并获取url地址的内容
  $output = curl_exec($ch);
  $errorCode = curl_errno($ch);
  //释放curl句柄
  curl_close($ch);
  if(0 !== $errorCode) {
    return false;
  }
  return $output;
}

http_build_query($data)！！！！！！！！！