Core PHP集成FCM推送通知图片无法显示问题求助

问题背景 #

使用Core PHP开发FCM推送通知功能，标题和正文可在Android设备正常显示，但图片无法加载；通过Firebase GUI发送时图片显示正常，Flutter端尝试通过${widget.message?.notification?.android?.imageUrl}获取图片URL。

问题原因 #

你当前在notification字段下直接嵌套android.imageUrl的写法不符合FCM的规范，标准的通知图片字段需要放在notification根节点（跨平台）或android.notification子节点（Android专属）中，也可通过data字段自定义传递。

解决方法 #

以下三种方案任选其一：

• 方案1：使用跨平台image字段
  在notification根节点直接添加image字段，FCM会自动适配Android和iOS的图片展示逻辑：

  $notification = [
      'title' => 'Title of the notification new',
      'body' => 'This is the body of the notification.',
      'image' => 'https://blog.pushwoosh.com/blog/content/images/2021/09/Android-12-Updates-for-Push-Notification-Senders---Pushwoosh.png'
  ];
  

• 方案2：使用Android专属嵌套结构
  若需针对Android单独配置，需将图片字段放在android.notification子节点下：

  $notification = [
      'title' => 'Title of the notification new',
      'body' => 'This is the body of the notification.',
      'android' => [
          'notification' => [
              'imageUrl' => 'https://blog.pushwoosh.com/blog/content/images/2021/09/Android-12-Updates-for-Push-Notification-Senders---Pushwoosh.png'
          ]
      ]
  ];
  

• 方案3：通过data字段自定义传递
  若需要Flutter端手动处理图片展示，可将图片URL放在data字段中，客户端从message.data中读取：

  $payload = [
      'to' => $token,
      'notification' => [
          'title' => 'Title of the notification new',
          'body' => 'This is the body of the notification.'
      ],
      'data' => [
          'imageUrl' => 'https://blog.pushwoosh.com/blog/content/images/2021/09/Android-12-Updates-for-Push-Notification-Senders---Pushwoosh.png'
      ]
  ];
  

修正后的完整代码示例（方案1） #

foreach ($allTokens as $token) {
    echo $token . "<br>";

    // 发送FCM通知的代码开始
    $notification = [
        'title' => 'Title of the notification new',
        'body' => 'This is the body of the notification.',
        'image' => 'https://blog.pushwoosh.com/blog/content/images/2021/09/Android-12-Updates-for-Push-Notification-Senders---Pushwoosh.png'
    ];

    $headers = [
        'Authorization: key=' . $serverKey,
        'Content-Type: application/json'
    ];

    $payload = [
        'to' => $token,
        'notification' => $notification
    ];

    $jsonPayload = json_encode($payload);

    try {
        $ch = curl_init('https://fcm.googleapis.com/fcm/send');
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $jsonPayload);

        $response = curl_exec($ch);

        if ($response === false) {
            throw new Exception('cURL error: ' . curl_error($ch));
        }

        echo 'Response: ' . $response . PHP_EOL;

        curl_close($ch);

        if ($response === false) {
            throw new Exception('Failed to send notification.');
        } else {
            echo 'Notification sent successfully.' . "<br><br>";
        }
    } catch (Exception $e) {
        echo 'Error: ' . $e->getMessage();
    }
    // 发送FCM通知的代码结束
}

内容的提问来源于stack exchange，提问作者sumit ace360