我的片段需要创建一个微调器来控制webview中显示的内容。还有一个进度条，显示微调器选择的加载。一切都在标准活动中运作良好，但将其移动到片段是有问题的。我将发布片段和错误。
谢谢！
错误发生在这一行：
spLoadFrom.setAdapter(spinnerArrayAdapter);
以下是代码：
package com.example.fragmenttest.app;
import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.ProgressBar;
import android.widget.Spinner;
public class BlankFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
public static final int DIALOG_DOWNLOAD_PROGRESS = 0;
ProgressBar pd = null;
public static final String PREFS_NAME2 = "SearchFile";
Spinner spLoadFrom;
WebView wv;
private LinearLayout container;
private Button nextButton, closeButton;
private EditText findBox;
private ArrayAdapter<CharSequence> spinnerArrayAdapter;
String name[] = { "mystuff" };
String displayName[] = {
"mystuff" };
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment BlankFragment.
*/
// TODO: Rename and change types and number of parameters
public static BlankFragment newInstance(String param1, String param2) {
BlankFragment fragment = new BlankFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public BlankFragment() {
// Required empty public constructor
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
wv = (WebView) container.findViewById(R.id.webview);
pd = (ProgressBar) container.findViewById(R.id.pBar);
spLoadFrom = (Spinner) container.findViewById(R.id.Spinner02);
ArrayAdapter<String> spinnerArrayAdapter = new ArrayAdapter<String>(this.getActivity(), android.R.layout.simple_spinner_item, displayName);
spinnerArrayAdapter.setDropDownViewResource(android.R.layout.simple_dropdown_item_1line);
spLoadFrom.setAdapter(spinnerArrayAdapter);
SpinnerListener spListener = new SpinnerListener();
spLoadFrom.setOnItemSelectedListener(spListener);
// Inflate the layout for this fragment
return inflater.inflate(R.layout.atcsectionweb2, container, false);
}
public class SpinnerListener implements AdapterView.OnItemSelectedListener {
public SpinnerListener() {
}
public void onItemSelected(AdapterView<?> arg0, View arg1,
final int position, long arg2) {
WebView wv = (WebView) getView().findViewById(R.id.webview);
wv.setWebChromeClient(new WebChromeClient() {
public void onProgressChanged(WebView view, int progress) {
if (progress < 100
&& pd.getVisibility() == ProgressBar.GONE) {
pd.setVisibility(ProgressBar.VISIBLE);
}
pd.setProgress(progress);
if (progress == 100) {
pd.setVisibility(ProgressBar.GONE);
}
}
});
wv.getSettings().setLoadWithOverviewMode(true);
wv.getSettings().setUseWideViewPort(true);
wv.getSettings().setBuiltInZoomControls(true);
wv.getSettings().setSupportZoom(true);
wv.setWebViewClient(new WebViewClient() {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
});
wv.loadUrl("file:///android_asset/" + name[position]);
}
public void onNothingSelected(AdapterView<?> arg0) {
}
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(Uri uri);
}
}
错误：
04-23 19:17:10.621 9679-9679/com.example.fragmenttest.app E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.fragmenttest.app, PID: 9679
java.lang.NullPointerException
at com.example.fragmenttest.app.BlankFragment.onCreateView(BlankFragment.java:243)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1500)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:938)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1115)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1478)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:446)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:798)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:614)
at miui.dexspy.DexspyInstaller.main(DexspyInstaller.java:171)
at dalvik.system.NativeStart.main(Native Method)
这是XML：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<ProgressBar
android:id="@+id/pBar"
style="?android:attr/progressBarStyleHorizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<Spinner
android:id="@+id/Spinner02"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/pBar" />
<WebView
android:id="@+id/webview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="@+id/Spinner02" />
<LinearLayout
android:id="@+id/layoutId"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignTop="@+id/webview"
android:orientation="horizontal" >
</LinearLayout>
</RelativeLayout>
答案 0 :(得分：1)
您必须使用膨胀的片段布局：
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.atcsectionweb2, container, false);
wv = (WebView) v.findViewById(R.id.webview);
pd = (ProgressBar) v.findViewById(R.id.pBar);
spLoadFrom = (Spinner) v.findViewById(R.id.Spinner02);
(...)
return v;
}
答案 1 :(得分：0)
我在设置适配器到片段中的微调器时遇到了同样的问题....并通过....解决了它。
if（getActivity（）！= null）{ spLoadFrom.setAdapter（spinnerArrayAdapter）; }