如何使用PHP開發微信小程式的任務分享功能？

{
  "title": "完成任务",
  "content": "完成任务并分享给好友",
  "image": "http://example.com/task.png"
}

$appid = 'your_appid';
$secret = 'your_appsecret';

$accessToken = getAccessToken($appid, $secret); // 获取访问令牌

$apiUrl = 'https://api.weixin.qq.com/wxa/getwxacode?access_token='.$accessToken;

$postData = array(
  'path' => 'pages/index', // 小程序的页面路径，可以根据实际需求修改
  'width' => 128, // 小程序码的宽度，可以根据实际需求修改
);

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $apiUrl);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($postData));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
curl_close($ch);

file_put_contents('/path/to/task.png', $response); // 将小程序码保存为图片文件

$code = $_GET['code']; // 从小程序端获取用户的code
$url = 'https://api.weixin.qq.com/sns/jscode2session?appid='.$appid.'&secret='.$secret.'&js_code='.$code.'&grant_type=authorization_code';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
curl_close($ch);

$result = json_decode($response, true);
$openid = $result['openid']; // 用户的openid

$task = array(
  "title" => "完成任务",
  "content" => "完成任务并分享给好友",
  "image" => "http://example.com/task.png"
);

$shareLink = 'http://example.com/share.php?task='.urlencode(json_encode($task)).'&openid='.$openid;