无法访问“findViewById"在异步任务中 [英] Can't access "findViewById" in AsyncTask

问题描述

我正在使用 AsyncTask 类从 php 文件下载数据.下载后，我想把这些数据，放到不同的TextView中，但是findViewById这个方法不能用.

I'm using an AsyncTask class to download data from a php file. After downloading, I want to put this data, into different TextViews, but I can't use the method findViewById.

问题在于，我是通过单独的类来执行此操作的，并且所有这些都在一个片段中.

The problem, is that I'm doing this by separate classes, and it all within a fragment.

这是我的代码:

public class RecuperarComentarisFoto extends AsyncTask<String, String, String>{
private Context mContext;
[...]
public RecuperarComentarisFoto(Context context){
    this.mContext=context;
}
@Override
protected void onPreExecute() {
    [...]
}

@Override
protected String doInBackground(String... arg0) { 
    params.add(new BasicNameValuePair("pid", "1"));
    JSONObject json = jsonParser.makeHttpRequest(url_get_comentaris, "GET", params);
    JSONArray productObj;
    //HERE I RETRIEVE DATA FROM JSON. ITS WORKING OK.

    return null;
}

我的问题在哪里:

@Override
protected void onPostExecute(String result) {
    super.onPostExecute(result);
    this.pDialog.dismiss();
    TextView comentariEditText = (TextView) findViewById(R.id.commentsMostrar);
}

我已经试过了:

        TextView comentariEditText = (TextView) mContext.findViewById(R.id.commentsMostrar);

但也不起作用.

请注意，我是从 Fragment 调用此 AsyncTask.如您所见，我必须将 getActivity() 检索到的上下文传递给 AsyncTask:

Note that I'm calling this AsyncTask from a Fragment. As you can see, I had to pass the context retrieved by getActivity() to the AsyncTask:

public class MyFragmentA extends Fragment {
Context cont;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    View myFragmentView = inflater.inflate(R.layout.fragment_a, container, false);

    cont=getActivity();
    new RecuperarComentarisFoto(cont).execute();
    return myFragmentView;
}


}

我该怎么办?

谢谢.

推荐答案

像这样将膨胀的视图传递给 AsyncTask :

Pass your inflated view to the AsyncTask like this :

public class RecuperarComentarisFoto extends AsyncTask<String, String, String>{
private Context mContext;
private View rootView;
[...]
public RecuperarComentarisFoto(Context context, View rootView){
    this.mContext=context;
    this.rootView=rootView;
}
@Override
protected void onPreExecute() {
    [...]
}

@Override
protected String doInBackground(String... arg0) { 
    params.add(new BasicNameValuePair("pid", "1"));
    JSONObject json = jsonParser.makeHttpRequest(url_get_comentaris, "GET", params);
    JSONArray productObj;
    //HERE I RETRIEVE DATA FROM JSON. ITS WORKING OK.

    return null;
}
@Override
protected void onPostExecute(String result) {
    //super.onPostExecute(result);  <--GET RID OF THIS (it will screw up on 2.1 devices)
    this.pDialog.dismiss();
    // use rootview to findViewById
    TextView comentariEditText = (TextView) rootView.findViewById(R.id.commentsMostrar);
}

然后这样调用，

View myFragmentView = inflater.inflate(R.layout.fragment_a, container, false);

cont=getActivity();
new RecuperarComentarisFoto(cont, myFragmentView).execute();

这篇关于无法访问“findViewById"在异步任务中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！