2010-04-28 91 views
2

我想创建一个列表视图,其中可以显示HTML内容,WebView和其他基本TextViews.I的TextView我试图扩展SimpleAdapter,但我碰到了问题,我会很高兴如果有人可以指出我正在做的错误。无法理解NullPointerException与自定义适配器

在onCreate方法

ArrayList<HashMap<String, String>> mylist= resultfromXmlparser(); 

adap = new MyAdapter(TourLandingPage.this, mylist, R.layout.row, 
      new String[] {"Name", "desc","Duration","Price","imgurl"}, new int[] 
      {R.id.productname,R.id.des,R.id.duration,R.id.pricefrom,R.id.photo}); 

setListAdapter(adap); 


My custom Adapter looks like this 

private class MyAdapter extends SimpleAdapter { 

      ArrayList<HashMap<String,String>> elements; 
      Context ctx; 
      public MyAdapter(Context context, ArrayList<HashMap<String,String>> mylist,int textViewResourceId,String[] names,int[] resouceid) { 
      super(context, mylist,textViewResourceId, names,resouceid); 
      this.elements=mylist; 
      this.ctx=context; 

      } 
      @Override 
      public int getCount() { 
        return elements.size(); 
       } 
      @Override 
      public Object getItem(int position) { 
        return elements.get(position); 
       } 
      @Override 
      public long getItemId(int position) { 
        return position; 
       } 


        @Override 
      public View getView(int position, View convertView, ViewGroup parent) { 
      RelativeLayout rowLayout; 
        if (convertView == null) { 
        rowLayout = (RelativeLayout) 
         LayoutInflater.from(ctx).inflate(R.layout.rowfor_tourlist, parent, false); 

       } else { 

       rowLayout = (RelativeLayout) convertView; 
        } 


        TextView in = (TextView)rowLayout.findViewById(R.id.introduction); 
        TextView du = (TextView)rowLayout.findViewById(R.id.duration); 
        TextView pf = (TextView)rowLayout.findViewById(R.id.pricefrom); 
        TextView pn = (TextView)rowLayout.findViewById(R.id.productname); 
        WebView wv=(WebView)rowLayout.findViewById(R.id.photo); 
        in.setText(Html.fromHtml(mylist.get(position).get("desc"))); 
        du.setText(mylist.get(position).get("Duration")); 
        pf.setText(mylist.get(position).get("Price")); 
        pn.setText(mylist.get(position).get("Name")); 
        wv.getSettings().setJavaScriptEnabled(true); 
        wv.loadUrl(mylist.get(position).get("imgurl")); 


       return convertView; 
      }   
     }//class 

和我row.xml文件看起来像

RelativeLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 

    TextView 
     android:id="@+id/productname" 
     ...... 

    LinearLayout 
     android:layout_width="wrap_content" 
     android:layout_height="60dip" 
     android:layout_margin="5dip" 
     android:layout_below="@id/productname" 
     android:orientation="horizontal" 
     android:id="@+id/lay1" 

     WebView 
      android:id="@+id/photo" 
      .... 
     TextView 
      android:id="@+id/introduction" 
      ...... 
    LinearLayout 

    TextView 
     android:id="@+id/duration" 
     .... 
    TextView 
    android:id="@+id/pricefrom" 
     ..... 

RelativeLayout 

我渐渐的错误是

04-28 19:46:17.749: ERROR/AndroidRuntime(976): Uncaught handler: thread main exiting due to uncaught exception 
04-28 19:46:17.769: ERROR/AndroidRuntime(976): java.lang.NullPointerException 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.ListView.setupChild(ListView.java:1693) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.ListView.makeAndAddView(ListView.java:1671) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.ListView.fillDown(ListView.java:637) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.ListView.fillFromTop(ListView.java:694) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.ListView.layoutChildren(ListView.java:1521) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.AbsListView.onLayout(AbsListView.java:1113) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.view.View.layout(View.java:6831) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.LinearLayout.layoutHorizontal(LinearLayout.java:1108) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.LinearLayout.onLayout(LinearLayout.java:920) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.view.View.layout(View.java:6831) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:998) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.LinearLayout.onLayout(LinearLayout.java:918) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.view.View.layout(View.java:6831) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.FrameLayout.onLayout(FrameLayout.java:333) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.view.View.layout(View.java:6831) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1119) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.LinearLayout.layoutVertical(LinearLayout.java:998) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.LinearLayout.onLayout(LinearLayout.java:918) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.view.View.layout(View.java:6831) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.widget.FrameLayout.onLayout(FrameLayout.java:333) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.view.View.layout(View.java:6831) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.view.ViewRoot.performTraversals(ViewRoot.java:996) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.view.ViewRoot.handleMessage(ViewRoot.java:1633) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.os.Handler.dispatchMessage(Handler.java:99) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.os.Looper.loop(Looper.java:123) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at android.app.ActivityThread.main(ActivityThread.java:4338) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at java.lang.reflect.Method.invokeNative(Native Method) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at java.lang.reflect.Method.invoke(Method.java:521) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 
04-28 19:46:17.769: ERROR/AndroidRuntime(976):  at dalvik.system.NativeStart.main(Native Method) 
04-28 19:46:17.789: INFO/Process(52): Sending signal. PID: 976 SIG: 3 
04-28 19:46:17.799: INFO/dalvikvm(976): threadid=7: reacting to signal 3 
04-28 19:46:17.829: INFO/dalvikvm(976): Wrote stack trace to '/data/anr/traces.txt' 
+0

如果可以重新格式化,将所有代码放在“代码”块等内,这将更容易筛选。 – 2010-04-28 14:48:17

+0

我只是忘记了在'BaseAdapter'中'返回convertView;'。 – 2014-09-04 20:06:05

回答

1

不知道这是否是原因,但SimpleAdapter构造函数的最后一个参数都应该是TextView。

SimpleAdapter

+0

谢谢你Comrades的'痛苦回答我的查询。我终于找到了解决方案 评论以下 // rowLayout =(RelativeLayout) LayoutInflater.from(ctx).inflate(R.layout.row,parent,假); 并替换此 \t LayoutInflater vi =(LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE); \t v = vi.inflate(R.layout.row,null); – ganesh 2010-04-28 15:41:01

+0

现在我遇到了另一个问题,我无法选择我的listView,即我的listView上的setOnItemClickListener不起作用,有人能帮助我。 – ganesh 2010-04-28 17:16:39

+0

@ganesh,是将'LayoutInflater.from(ctx)'改为'(LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);'或者是使用'inflate(R.layout.row,null)'来修改的解决方案充气(R.layout.row,父母,假);'? – cottonBallPaws 2012-11-26 19:40:08

3

正如我在上面的代码中看到,你的问题是“回归convertView;”线。您刚刚返回了一个输入视图,而不是夸大的视图。