所以我的应用程序启动并适用于viewpager的第一个片段，但在加载viewpager的第二个片段时崩溃。任何帮助将非常感激。 这是源代码：
public class PreviousWord extends Fragment {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle saveInstanceState) {
View v = (inflater.inflate(R.layout.activity_previous_word, container, false));
new GetWord().execute();
return v;
}
private class GetWord extends AsyncTask<Void,Void, Void>{
private Element data=null;
private Element data2=null;
private Element date=null;
private String wordName;
private String dates;
private TextView date1;
private TextView date2;
private TextView date3;
private TextView date4;
private TextView date5;
private TextView date6;
private ArrayList<String> wordList = new ArrayList<String>();
private ArrayList<String> dateList = new ArrayList<String>();
@Override
protected Void doInBackground(Void... arg0) {
Document doc = null;
try {
doc = Jsoup.connect("http://www.urbandictionary.com/").get();
for(int i = 1; i<7; i=i+1){
data = doc.getElementsByClass("word").get(i);
data2 = data.select("a[href]").first();
wordName = data2.text();
wordList.add(wordName);
date = doc.getElementsByClass("smallcaps").get(i);
dates = date.text();
dateList.add(dates);
date1 = (TextView) DailyWord.v.findViewById(R.id.text1);
date2 = (TextView) DailyWord.v.findViewById(R.id.text3);
date3 = (TextView) DailyWord.v.findViewById(R.id.text5);
date4 = (TextView) DailyWord.v.findViewById(R.id.text7);
date5 = (TextView) DailyWord.v.findViewById(R.id.text9);
date6 = (TextView) DailyWord.v.findViewById(R.id.text11);
}
}
catch (Exception e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
date1.setText(dateList.get(0));
date2.setText(dateList.get(1));
date3.setText(dateList.get(2));
date4.setText(dateList.get(3));
date5.setText(dateList.get(4));
date6.setText(dateList.get(5));
}
}
}
这是我的LogCat：
12-10 22:25:50.055: W/dalvikvm(19935): threadid=1: thread exiting with uncaught exception (group=0x40fbb2a0)
12-10 22:25:50.065: E/AndroidRuntime(19935): FATAL EXCEPTION: main
12-10 22:25:50.065: E/AndroidRuntime(19935): java.lang.NullPointerException
12-10 22:25:50.065: E/AndroidRuntime(19935): at com.dictionary.urbanword.PreviousWord$GetWord.onPostExecute(PreviousWord.java:75)
12-10 22:25:50.065: E/AndroidRuntime(19935): at com.dictionary.urbanword.PreviousWord$GetWord.onPostExecute(PreviousWord.java:1)
12-10 22:25:50.065: E/AndroidRuntime(19935): at android.os.AsyncTask.finish(AsyncTask.java:631)
12-10 22:25:50.065: E/AndroidRuntime(19935): at android.os.AsyncTask.access$600(AsyncTask.java:177)
12-10 22:25:50.065: E/AndroidRuntime(19935): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
12-10 22:25:50.065: E/AndroidRuntime(19935): at android.os.Handler.dispatchMessage(Handler.java:99)
12-10 22:25:50.065: E/AndroidRuntime(19935): at android.os.Looper.loop(Looper.java:137)
12-10 22:25:50.065: E/AndroidRuntime(19935): at android.app.ActivityThread.main(ActivityThread.java:4898)
12-10 22:25:50.065: E/AndroidRuntime(19935): at java.lang.reflect.Method.invokeNative(Native Method)
12-10 22:25:50.065: E/AndroidRuntime(19935): at java.lang.reflect.Method.invoke(Method.java:511)
12-10 22:25:50.065: E/AndroidRuntime(19935): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
12-10 22:25:50.065: E/AndroidRuntime(19935): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
12-10 22:25:50.065: E/AndroidRuntime(19935): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
假设activity_previous_word.xml中包含所有文字视图，请将您的代码更改为
public class PreviousWord extends Fragment {
private Element data=null;
private Element data2=null;
private Element date=null;
private String wordName,dates;
private TextView date1,date2,date3,date4,date5,date6;
private ArrayList<String> wordList = new ArrayList<String>();
private ArrayList<String> dateList = new ArrayList<String>();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle saveInstanceState) {
View v = (inflater.inflate(R.layout.activity_previous_word, container, false));
date1 = (TextView) v.findViewById(R.id.text1);
date2 = (TextView) v.findViewById(R.id.text3);
date3 = (TextView) v.findViewById(R.id.text5);
date4 = (TextView) v.findViewById(R.id.text7);
date5 = (TextView) v.findViewById(R.id.text9);
date6 = (TextView) v.findViewById(R.id.text11);
new GetWord().execute();
return v;
}
private class GetWord extends AsyncTask<Void,Void, Void>{
@Override
protected Void doInBackground(Void... arg0) {
Document doc = null;
try {
doc = Jsoup.connect("http://www.urbandictionary.com/").get();
for(int i = 1; i<7; i=i+1){
data = doc.getElementsByClass("word").get(i);
data2 = data.select("a[href]").first();
wordName = data2.text();
wordList.add(wordName);
date = doc.getElementsByClass("smallcaps").get(i);
dates = date.text();
dateList.add(dates);
}
}
catch (Exception e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
date1.setText(dateList.get(0));
date2.setText(dateList.get(1));
date3.setText(dateList.get(2));
date4.setText(dateList.get(3));
date5.setText(dateList.get(4));
date6.setText(dateList.get(5));
}
}
}
findViewById查找当前膨胀布局中提到的id的视图。因此，您需要使用膨胀的视图对象来初始化视图。