片段与ListView控件:上setAdapter NullPointerException异常 [英] Fragment with ListView: NullPointerException on setAdapter
问题描述
我的问题,我得到一个NullPointExeption时,我想设置一个适配器上的ListView我。
之前,我有扩展,ListFragment和一个简单的适配器的片段,其作品但问题是,我有这个活动的3个片段所有列表视图,我得到了显示错误(显示在一个片段中的错误列表)。所以我决定为在列表视图每个片段的IDS设置,但现在它不工作。
错误listview.setAdapter(适配器):
显示java.lang.NullPointerException在
de.resper.e2cast.MainFragmentLive.onCreateView(MainFragmentLive.java:46)
块引用>片段:
进口android.os.Bundle;
进口android.util.Log;
进口android.view.LayoutInflater;
进口android.view.View;
进口android.view.ViewGroup;
进口android.widget.ArrayAdapter;
进口android.widget.ImageButton;
进口android.widget.ListView;进口的java.util.ArrayList;
进口的java.util.List;进口de.resper.e2cast.classes.globalBox;
进口de.resper.e2cast.helper.getXml;
进口de.resper.e2cast.helper.parseXml;公共类MainFragmentLive扩展android.support.v4.app.Fragment { 私人列表<串GT; bouquetListString;
私人ArrayAdapter<串GT;适配器;
私人globalBox activeBox;
私人的ListView列表视图; @覆盖
公共查看onCreateView(LayoutInflater充气器,容器的ViewGroup,捆绑savedInstanceState){
查看查看= inflater.inflate(R.layout.fragment_main_live,集装箱,FALSE);
activeBox =((globalBox)getActivity()getApplicationContext());
bouquetListString =新的ArrayList<串GT;();
bouquetListString.add(载入中...);
如果(activeBox.isInit()){
如果(activeBox.getBouquets()大小()方式> 0&放大器;&放大器; activeBox.getBouquets()获得(2).size()大于0){
bouquetListString = activeBox.getBouquets()获取(2)。
}其他{
Log.d(加载花束,XML);
getBouquetBox();
}
}
列表视图=(ListView控件)getActivity()findViewById(R.id.listLive)。
适配器=新ArrayAdapter<串GT;(getActivity(),android.R.layout.simple_list_item_1,bouquetListString);
listview.setAdapter(适配器); 的ImageButton reloadBouquet =(的ImageButton)view.findViewById(R.id.reloadBouquet);
reloadBouquet.setOnClickListener(新View.OnClickListener(){
@覆盖
公共无效的onClick(查看为arg0){
getBouquetBox();
}
}); setHasOptionsMenu(真);
返回视图。
}
公共无效getBouquetBox(){
getXml.DownloadCompleteListener DCL =新getXml.DownloadCompleteListener(){
@覆盖
公共无效onDownloadComplete(字符串结果){
bouquetListString.clear();
的String [] =标签{e2servicereference,e2servicename};
清单<名单,LT;弦乐>> bouquetsList = parseXml.parseXmlByTag(结果,标签);
activeBox.addBouquets(bouquetsList);
bouquetListString.addAll(activeBox.getBouquets()获取(2));
adapter.notifyDataSetChanged();
}
};
Log.d(MyLogger,XML请求GET花束);
下载的getXML =新的getXML(DCL);
downloader.execute(HTTP://+ activeBox.getIpPort()+/网络/ getservices);
}
}XML片段:
<?XML版本=1.0编码=UTF-8&GT?;
< LinearLayout中的xmlns:机器人=http://schemas.android.com/apk/res/android
机器人:方向=垂直
机器人:layout_width =match_parent
机器人:layout_height =match_parent>
<的LinearLayout
机器人:layout_width =match_parent
机器人:layout_height =WRAP_CONTENT
机器人:方向=横向
机器人:layout_margin =8DP>
<的TextView
机器人:layout_width =0dip
机器人:layout_height =WRAP_CONTENT
机器人:layout_weight =0.8
机器人:文字=@字符串/ selectBouquet
风格=@风格/头1/>
<的ImageButton
机器人:layout_width =0dip
机器人:layout_height =WRAP_CONTENT
机器人:ID =@ + ID / reloadBouquet
机器人:SRC =@绘制/ ic_action_refresh
机器人:contentDescription =@字符串/搜索
机器人:layout_weight =20
机器人:layout_gravity =底/>
< / LinearLayout中>
<查看
机器人:layout_width =FILL_PARENT
机器人:layout_height =1DP
机器人:背景=@机器人:彩色/ darker_gray/>
< ListView控件
机器人:layout_width =match_parent
机器人:layout_height =WRAP_CONTENT
机器人:ID =@ + ID / listLive/>
< / LinearLayout中>
解决方案使用
视图
而不是getActivity()
在初始化的ListView因为ListView的是片段的布局,而不是里面的活动:=列表视图(ListView控件)view.findViewById(R.id.listLive);
I have the Problem, that I get a NullPointExeption when I want to set a adapter on my ListView. Before I had the Fragment extended with ListFragment and a simple Adapter, that works but the problem was, that I have 3 Fragments in this activity all with ListViews and I got display errors (shows the wrong list in a fragment). So I decided to set for every Fragment own ids on the Listview but now it doesnt work.
Error listview.setAdapter(adapter):
java.lang.NullPointerException at de.resper.e2cast.MainFragmentLive.onCreateView(MainFragmentLive.java:46)
Fragment:
import android.os.Bundle; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.ImageButton; import android.widget.ListView; import java.util.ArrayList; import java.util.List; import de.resper.e2cast.classes.globalBox; import de.resper.e2cast.helper.getXml; import de.resper.e2cast.helper.parseXml; public class MainFragmentLive extends android.support.v4.app.Fragment { private List<String> bouquetListString; private ArrayAdapter<String> adapter; private globalBox activeBox; private ListView listview; @Override public View onCreateView(LayoutInflater inflater,ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_main_live, container, false); activeBox = ((globalBox) getActivity().getApplicationContext()); bouquetListString = new ArrayList<String>(); bouquetListString.add("loading..."); if(activeBox.isInit()){ if(activeBox.getBouquets().size() > 0 && activeBox.getBouquets().get(2).size() > 0){ bouquetListString = activeBox.getBouquets().get(2); }else{ Log.d("Load Bouquet", "XML"); getBouquetBox(); } } listview = (ListView) getActivity().findViewById(R.id.listLive); adapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_list_item_1, bouquetListString); listview.setAdapter(adapter); ImageButton reloadBouquet = (ImageButton) view.findViewById(R.id.reloadBouquet); reloadBouquet.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View arg0) { getBouquetBox(); } }); setHasOptionsMenu(true); return view; } public void getBouquetBox(){ getXml.DownloadCompleteListener dcl = new getXml.DownloadCompleteListener() { @Override public void onDownloadComplete(String result) { bouquetListString.clear(); String [] tags = {"e2servicereference", "e2servicename"}; List<List<String>> bouquetsList = parseXml.parseXmlByTag(result, tags); activeBox.addBouquets(bouquetsList); bouquetListString.addAll(activeBox.getBouquets().get(2)); adapter.notifyDataSetChanged(); } }; Log.d("MyLogger", "XML Request GET BOUQUET"); getXml downloader = new getXml(dcl); downloader.execute("http://" + activeBox.getIpPort() + "/web/getservices"); } }
Fragment XML:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:layout_margin="8dp"> <TextView android:layout_width="0dip" android:layout_height="wrap_content" android:layout_weight="0.8" android:text="@string/selectBouquet" style="@style/header1"/> <ImageButton android:layout_width="0dip" android:layout_height="wrap_content" android:id="@+id/reloadBouquet" android:src="@drawable/ic_action_refresh" android:contentDescription="@string/search" android:layout_weight=".20" android:layout_gravity="bottom"/> </LinearLayout> <View android:layout_width="fill_parent" android:layout_height="1dp" android:background="@android:color/darker_gray"/> <ListView android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/listLive" /> </LinearLayout>
解决方案Use
view
instead ofgetActivity()
to initializing ListView because ListView is inside Fragment layout instead of Activity :listview = (ListView) view.findViewById(R.id.listLive);
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