支持文件

src/Wechat/Work/Message/MessageInterface.php

@@ -67,6 +67,7 @@ abstract class MessageInterface
                     $this->type => $this->attr,
                 ]);
                 break;
+            case self::TYPE_FILE:
             case self::TYPE_IMAGE:
                 $params = array_merge($params, [
                     $this->type => [

src/Wechat/Work/Message/TextFileMessage.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Wechat\Work\Message;
+
+use Wechat\Work\Message\MessageInterface;
+
+class TextFileMessage extends MessageInterface
+{
+
+    public function __construct($content)
+    {
+        $this->type = self::TYPE_FILE;
+        $this->attr['media_id'] = $content;
+    }
+
+}