php http_build_query stream_context_create post请求

 <?php
 function send_post($url, $post_data)
 {
     $postdata = http_build_query($post_data);
     $options = array(
         'http' => array(
             'method' => 'POST',
             'header' => 'Content-type:application/x-www-form-urlencoded',
             'content' => $postdata,
             'timeout' => 15 * 60 // 超时时间（单位:s）
         )
     );
     $context = stream_context_create($options);
     $result = file_get_contents($url, false, $context);

     echo $result;
 }

 //使用方法
 $post_data = array(
     'a' => '11',
     'b' => '22'
 );
 send_post('http://localhost/b.php', $post_data);