title: How to save a List<Object> and retrieve using Hive?
body: <p>I have a Wallpaper App and it uses Firestore to store the wallpapers.</p>
  
  <p>I want to use Hive to store a list of wallpapers from cloud firestore but how to save the List of Wallpapers and retrieve it later?</p>
  
  <p>When I try to save the list I get this error:</p>
  
  <blockquote>
    <p>E/flutter ( 9995): [ERROR:flutter/shell/common/shell.cc(199)] Dart Error: Unhandled exception:
       E/flutter ( 9995): HiveError: Cannot write, unknown type: Wallpaper. Did you forget to register an adapter?</p>
  </blockquote>
  
  <p>Code:</p>
  
  <pre><code>class Wallpaper extends HiveObject {
  
  
    String date;
    String url;
  
    Wallpaper();
  
  }
  
  static Future&lt;void&gt; addWallpapers({@required String boxName, @required List&lt;Wallpaper&gt; wallpapers}) async {
  
      var box = await Hive.openBox(boxName);
      box.put(boxName, wallpapers);
  
      print("WALLPAPER ADICIONADO NO HIVE!");
  
    }
  
    static Future&lt;List&lt;Wallpaper&gt;&gt; getWallpapers({@required String boxName}) async {
  
      var box = await Hive.openBox(boxName);
  
      List&lt;Wallpaper&gt; wallpapers = box.get("latest");
  
      return wallpapers;
  
    }
  </code></pre>