我正在尝试Button
在onPostExecute
. AsyncTask
我在扩展的类中执行此操作Fragment
。我可以使用此代码动态创建一个Button
外部AsyncTask
:
public class Tab2Fragment extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
LinearLayout theLayout = (LinearLayout) inflater.inflate(R.layout.tab2, container, false);
Context mFragmentContext=getActivity().getApplicationContext();
Button btn=new Button(mFragmentContext);
btn.setText("Hello Button");
RelativeLayout.LayoutParams paramsd = new RelativeLayout.LayoutParams(150,30);
paramsd.height = paramsd.WRAP_CONTENT;
paramsd.width = paramsd.WRAP_CONTENT;
btn.setLayoutParams(paramsd);
theLayout.addView(btn);
Button test = (Button)theLayout.findViewById(R.id.test41);
test.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.v("response", "Button Clicked");
new loadSomeStuff().execute();
Intent log = new Intent();
log.setClass(getActivity(), Assignment.class);
startActivity(log);
}
});
return theLayout;
}
// Method to load stuff using async task. Grabs information from URL and
// calls read stream
public class loadSomeStuff extends AsyncTask<String, Integer, String> {
protected String doInBackground(String... arg0) {
try {
int limit = 100;
String accessToken = "";
URL url = new URL( "SomeSite" + accessToken
+ "&status=active" + "&limit=" + limit);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestProperty("Accept", "application/json");
readStream(con.getInputStream());
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute( String result ) {
super.onPostExecute(result);
Context mFragmentContext=getActivity().getApplicationContext();
Button btn=new Button(mFragmentContext);
btn.setText("Hello Button");
RelativeLayout.LayoutParams paramsd = new RelativeLayout.LayoutParams(150,30);
paramsd.height = paramsd.WRAP_CONTENT;
paramsd.width = paramsd.WRAP_CONTENT;
btn.setLayoutParams(paramsd);
//theLayout.addView(btn);
Log.v("response", "on post biatch");
}
}
// Processes information from URL and prints it in format
private void readStream(InputStream in) throws JSONException {
BufferedReader reader = null;
try {
reader = new BufferedReader(new InputStreamReader(in));
String line = reader.readLine();
String total_results = new JSONObject(line).getJSONObject(
"response").getString("total_results");
int assignCount = Integer.parseInt(total_results.toString());
Log.v("response", total_results);
JSONObject data;
for (int i = 0; i < assignCount; i++) {
data = new JSONObject(line).getJSONObject("response");
String id = data.getJSONArray("data").getJSONObject(i).getString("id");
String title = data.getJSONArray("data").getJSONObject(i).getString("title");
Log.v("response", title);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
问题是,当我尝试将此代码放入onPostExecute
of 时AsyncTask
,addview(btn)
行有错误,因为Layout
未定义。我不知道如何通过Layout
. Layout
有没有办法通过某种内置方法来获取活动?