Question

我的listview的适配器有问题，我不知道在我的代码中我必须添加notifyDataSetChanged（），如果我在logcat中运行此代码会出错：

    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. Make sure your adapter calls notifyDataSetChanged() when its content changes. [in ListView(2131165276, class android.widget.ListView)]

我的asynctask：

    class UpdateData extends AsyncTask<Void, Void, JSONArray> {
    String result = "";
    JSONArray jArray = null;


    @Override
    protected void onPostExecute(JSONArray result) {
        super.onPostExecute(result);
        adapter.addAll(deptList);
        adapter.notifyDataSetChanged();
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }


    @Override
    protected JSONArray doInBackground(Void... arg0) {
            ....

        try {
            JSONArray array = new JSONArray(result);
            for (int i = 0; i < array.length(); i++) {
                JSONObject j = array.getJSONObject(i);
                EventCalendarStrings d = new EventCalendarStrings();
                d.name = j.optString("name", "");
                d.kategorie = j.optString("Art", "");
                deptList.add(d);
            }

        } catch (JSONException e) {
            Log.e("log_tag", "No connection " + e.toString());
        }
        }
        return jArray;
    }

Answer 1

它进入onPostExecute()，因为它是在UI线程上执行的。在doInBackground()中调用它将导致该异常。

Answer 2

试试这个

 @Override
    protected void onPostExecute(JSONArray result) {
        super.onPostExecute(result);
        runOnUiThread(new Runnable(){
                public void run(){
                adapter.addAll(deptList);
                adapter.notifyDataSetChanged();

                }
            });
    }

或

 @Override
    protected void onPostExecute(JSONArray result) {
        super.onPostExecute(result);
        runOnUiThread(new Runnable(){
                public void run(){
                adapter.addAll(deptList);
                listview.setAdapater(adapter);
                }
            });
    }

asynctask之后的Android ListView更新

2 个答案: