使用 AsyncTask with Fragments，ArrayAdapter 要求资源 ID 为 TextView

Question

如何实现AsyncTask 我有片段，我应该在行中写什么

listview = (ListView) ?????? findViewById(R.id.listviewget);

如果我把它放在 onCreateView

 listview = (ListView) veiw.findViewById(R.id.listviewget);

我得到错误 below.All 获取代码工作是因为我已经签入 activity 并且它从服务器获取数据但不能在片段中工作

01-22 21:59:32.850: E/ArrayAdapter(32155): You must supply a resource ID for a TextView 01-22 21:59:32.890: E/AndroidRuntime(32155): FATAL EXCEPTION: main 01-22 21:59:32.890: E/AndroidRuntime(32155): java.lang.IllegalStateException: ArrayAdapter requires the resource ID to be a TextView 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:386) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.ArrayAdapter.getView(ArrayAdapter.java:362) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.AbsListView.obtainView(AbsListView.java:2075) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.ListView.makeAndAddView(ListView.java:2004) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.ListView.fillDown(ListView.java:856) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.ListView.fillFromTop(ListView.java:916) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.ListView.layoutChildren(ListView.java:1857) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.AbsListView.onLayout(AbsListView.java:1905) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.View.layout(View.java:11359) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.ViewGroup.layout(ViewGroup.java:4531) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.RelativeLayout.onLayout(RelativeLayout.java:925) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.View.layout(View.java:11359) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.ViewGroup.layout(ViewGroup.java:4531) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.FrameLayout.onLayout(FrameLayout.java:431) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.View.layout(View.java:11359) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.ViewGroup.layout(ViewGroup.java:4531) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:801) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.View.layout(View.java:11359) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.ViewGroup.layout(ViewGroup.java:4531) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.FrameLayout.onLayout(FrameLayout.java:431) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.View.layout(View.java:11359) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.ViewGroup.layout(ViewGroup.java:4531) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1486) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.LinearLayout.onLayout(LinearLayout.java:1399) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.View.layout(View.java:11359) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.ViewGroup.layout(ViewGroup.java:4531) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.FrameLayout.onLayout(FrameLayout.java:431) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.View.layout(View.java:11359) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.ViewGroup.layout(ViewGroup.java:4531) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1665) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2695) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.os.Handler.dispatchMessage(Handler.java:99) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.os.Looper.loop(Looper.java:156) 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.app.ActivityThread.main(ActivityThread.java:4987) 01-22 21:59:32.890: E/AndroidRuntime(32155): at java.lang.reflect.Method.invokeNative(Native Method) 01-22 21:59:32.890: E/AndroidRuntime(32155): at java.lang.reflect.Method.invoke(Method.java:511) 01-22 21:59:32.890: E/AndroidRuntime(32155): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 01-22 21:59:32.890: E/AndroidRuntime(32155): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 01-22 21:59:32.890: E/AndroidRuntime(32155): at dalvik.system.NativeStart.main(Native Method) 01-22 21:59:32.890: E/AndroidRuntime(32155): Caused by: java.lang.ClassCastException: android.widget.RelativeLayout cannot be cast to android.widget.TextView 01-22 21:59:32.890: E/AndroidRuntime(32155): at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:379) 01-22 21:59:32.890: E/AndroidRuntime(32155): ... 39 more

public class MyLibrary  extends Fragment {
ListView listview;
List<ParseObject> data;
ProgressDialog mProgressDialog;
ArrayAdapter<String> adapter;


public MyLibrary()
{

}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    Parse.initialize(getActivity(), "ASD", "ASD");
    ParseUser.enableAutomaticUser();
    ParseACL defaultACL = new ParseACL();
    defaultACL.setPublicReadAccess(true);
    ParseACL.setDefaultACL(defaultACL, true);
    View view=inflater.inflate(R.layout.getnewlay,container, false);
    new GetData().execute();
    return view;
}

private class GetData extends AsyncTask<Void, Void, Void> {
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        mProgressDialog = new ProgressDialog(getActivity());
        mProgressDialog.setTitle("Please wait");
        mProgressDialog.setMessage("Getting data...");
        mProgressDialog.setIndeterminate(false);
        mProgressDialog.show();
    }

    @Override
    protected Void doInBackground(Void... params) {
        ParseQuery query = new ParseQuery("ASD");
        query.orderByDescending("_created_at");
        try {
            data= query.find();


        } catch (ParseException e) {

            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        listview = (ListView) ?????? findViewById(R.id.listviewget);

        adapter = new ArrayAdapter<String>(getActivity(),
                R.layout.getnewlay);
        for (ParseObject name : data) {
            adapter.add((String) name.get("name"));
        }
        listview.setAdapter(adapter);
        mProgressDialog.dismiss();

    }
}

}

Answer 1

ArrayAdapter requires the resource ID to be a TextView

意味着 R.layout.getnewlay 布局包含 TextView 但在 RelativeLayout 内部，因此您可以将任何 id 分配给 TextView 并使用 ArrayAdapter 的另一个构造函数，它需要 TextView id:

adapter = new ArrayAdapter<String>(getActivity(),
                R.layout.getnewlay,R.id.textView_Id);

或从 xml 中删除 RelativeLayout 布局并使 TextView 作为根视图：

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"    
    .....
/>

How to access View from Fragment layout in onPostExecute method:

使用getView方法：

listview = (ListView)getView().findViewById(R.id.listviewget);

Answer 2

检查您的布局getnewlay。它在布局中应该只有 TextView 作为父级（甚至没有任何布局，如线性或相对布局）

否则你可以用 android.R.layout.simple_list_item_1 代替 R.layout.getnewlay

Answer 3

在布局中传递 TextView 的资源 ID 'getnewlay' 喜欢

adapter = new ArrayAdapter<>(getActivity(), R.layout.getnewlay, R.id.textViewResourceId_in_getnewlay)

使用 AsyncTask with Fragments，ArrayAdapter 要求资源 ID 为 TextView

Using AsyncTask with Fragments,ArrayAdapter requires the resource ID to be a TextView

android

android-listview

android-asynctask