android - 内容适配器和异步回调

Question

我正在使用第三方云服务 (Kinvey) 为我的应用获取数据。所有服务的 Kinvey 方法都包装在异步类中。我目前在下面收到错误日志，我明白我为什么会收到它。我只是不知道如何解决这个问题。

错误:

03-12 13:41:03.449: E/AndroidRuntime(18375): FATAL EXCEPTION: main

03-12 13:41:03.449: E/AndroidRuntime(18375): java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. [in ListView(2130968661, class android.widget.ListView) with Adapter(class com.example.chartviewer.LazyAdapter)]

这是我在异步方法中删除内容后通知我的适配器的代码段:

mKinveyClient.appData("artistdata", ArtistData.class).delete(artistID, new KinveyDeleteCallback() {

       @Override
        public void onSuccess(KinveyDeleteResponse result) {

              Log.e("DELEET", "Data Deleted sucessfully");
              Toast.makeText(getBaseContext(),
                      "Artist Deleted", Toast.LENGTH_SHORT).show();

                //refreshes list 
            adapter.notifyDataSetChanged(); 

           //displays dialog box if no artists left 
           displayNoArtist();

        }
        @Override
        public void onFailure(Throwable error) {
             Log.e("DELETE", "AppData.delete Failure", error);
        }
    });

更新适配器:

mKinveyClient.appData("artistdata", ArtistData.class).get(myQuery, new 
KinveyListCallback<ArtistData>() {
         @Override
         public void onSuccess(ArtistData[] result) {

              Log.e("FETCHING", "Data fetched sucessfully");
             for (ArtistData data : result) {


                 String name= data.getArtistname();
                 String imageurl = data.getArtisturl();

                 String id = data.getArtistid();

                 artistIds.add(id);

                  HashMap<String, String> hashMap = new HashMap<String, String>();

                  hashMap.put(TAG_NAME, name);
                  hashMap.put(TAG_IMAGEURL, imageurl);

                  addMyArtists(hashMap);


             }

             displayData();

         }

         @Override
         public void onFailure(Throwable error) {

             Log.e("FETCHING", "AppData.get by Query Failure", error);

         }
     });

适配器创建者代码:

      list = (ListView)findViewById(R.id.artistlist);
      adapter = new LazyAdapter(MyArtistsActivity.this,"artists", artistItemList);
      list.setAdapter(adapter);
      registerForContextMenu(list);

Answer 1

免责声明:我是 Kinvey 工程团队的成员。

问题是您在从 Kinvey 后端删除之前从 artistItemList 中删除，然后在回调之前不调用 adapter.notifyDatasetChanged。这会导致您在等待后端 Kinvey 删除调用的回调时注意到基础数据集发生更改的延迟。您需要将这两个调用组合在一起，并通过以下两种方式之一进行:

1. 将传递给 delete 方法的 artistID 设为最终值，并在 onSuccess 中从 artistItemList 中删除该项目，然后再调用 adapter.notifyDatasetChanged。
2. 在从 artistItemList 中删除项目后立即调用 kinveyClient.appData().delete() 方法之前调用 adapter.notifyDatasetChanged。如果在 Kinvey 后端删除失败，此选项可能会导致问题。