我有一个自定义ListAdapter的获取数据从互联网中的AsyncTask。

中的数据完全添加到列表中，但是当我尝试做业务应用程序崩溃...

我敢肯定，这是因为我打电话notifyDataSetChanged（）;在错误的时间（即AsyncTask的结束之前）。

我有什么现在的：

 公共类MyListAdapter扩展了BaseAdapter {
    私人的ArrayList＆LT;字符串＆GT; mStrings =新的ArrayList＆LT;字符串＆GT;（）;

    公共MyListAdapter（）{
        新RetreiveStringsTask（）执行（internet_url）;
        //这里我所说的通知功能****************
        this.notifyDataSetChanged（）;
    }

    类RetreiveStringsTask扩展的AsyncTask＆LT;字符串，无效的ArrayList＆LT;字符串＆GT;＆GT; {
        私人例外的例外;

        @覆盖
        受保护的ArrayList＆LT;字符串＆GT; doInBackground（字符串...网址）{
            尝试 {
                网址URL =新的URL（网址[0]）;
                //返回数组列表
                返回getStringsFromInternet（URL）;;
            }赶上（例外五）{
                this.exception = E;
                Log.e（AsyncTask的，exception.toString（））;
                返回null;
            }
        }

        @覆盖
        保护无效onPostExecute（ArrayList中＆LT;字符串＆GT; stringsArray）{
            //从互联网上添加旅行团到数组
            如果（stringsArray！= NULL）{
                mStrings.addAll（toursArray）;
            }
        }
    }
}
 

我的问题是：我可以打电话notifyDataSetChanged（）从AsyncTask的，或在其他任何时间的onPostExecute功能，当AsyncTask的已取出的数据

我可以调用notifyDataSetChanged（）从onPostExecute功能   在AsyncTask的

是的，你可以叫 notifyDataSetChanged（）从 onPostExecute 来更新适配器数据时 doInBackground 执行完毕。做到这一点的：

  @覆盖
保护无效onPostExecute（ArrayList中＆LT;字符串＆GT; stringsArray）{
    //从互联网上添加旅行团到数组
    如果（stringsArray！= NULL）{
        mStrings.addAll（toursArray）;
        //调用notifyDataSetChanged（）在这里...
         MyListAdapter.this.notifyDataSetChanged（）;
    }
}
 

I've a custom ListAdapter that fetches data from internet in an AsyncTask.

The data is added perfectly to the list, but when I try to do operations the application crashes...

I'm sure this is because I'm calling notifyDataSetChanged(); at the wrong time (i.e. before the AsyncTask ends).

What I've got now:

public class MyListAdapter extends BaseAdapter {
    private ArrayList<String> mStrings = new ArrayList<String>();

    public MyListAdapter() {
        new RetreiveStringsTask().execute(internet_url);
        //here I call the notify function ****************
        this.notifyDataSetChanged();
    }

    class RetreiveStringsTask extends AsyncTask<String, Void, ArrayList<String>> {
        private Exception exception;

        @Override
        protected ArrayList<String> doInBackground(String... urls) {
            try {
                URL url= new URL(urls[0]);
                //return arraylist
                return getStringsFromInternet(url);;
            } catch (Exception e) {
                this.exception = e;
                Log.e("AsyncTask", exception.toString());
                return null;
            }
        }

        @Override
        protected void onPostExecute(ArrayList<String> stringsArray) {
            //add the tours from internet to the array
            if(stringsArray != null) {
                mStrings.addAll(toursArray);
            }
        }
    }
}

My question is: can I call notifyDataSetChanged() from the onPostExecute function in the AsyncTask or at any other time when the AsyncTask has fetched the data?

can I call notifyDataSetChanged() from the onPostExecute function in the AsyncTask

Yes, you can call notifyDataSetChanged() from onPostExecute to Update Adapter data when doInBackground execution complete. do it as:

@Override
protected void onPostExecute(ArrayList<String> stringsArray) {
    //add the tours from internet to the array
    if(stringsArray != null) {
        mStrings.addAll(toursArray);
        // call notifyDataSetChanged() here...
         MyListAdapter.this.notifyDataSetChanged();
    }
}