Getting errors / crashing when listview reaches at the end of the list

Issue

I am getting an error in my app then it crashes when I reach at the end of the listview. Not sure what is causing this problem and how to solve this issue. I use a cursor to populate my listview. This is my code that I used to populate the listview from:

How to assing an Image to Imageview based on a query results?

Error:

11-15 12:45:22.446: E/AndroidRuntime(276): FATAL EXCEPTION: main
11-15 12:45:22.446: E/AndroidRuntime(276): java.lang.NullPointerException
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.content.res.AssetManager.getResourceIdentifier(Native Method)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.content.res.Resources.getIdentifier(Resources.java:1422)
11-15 12:45:22.446: E/AndroidRuntime(276):  at com.example.yao.zCustomUsersAdapter.getView(zCustomUsersAdapter.java:62)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.widget.AbsListView.obtainView(AbsListView.java:1294)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.widget.ListView.makeAndAddView(ListView.java:1727)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.widget.ListView.fillDown(ListView.java:652)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.widget.ListView.fillGap(ListView.java:623)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.widget.AbsListView.trackMotionScroll(AbsListView.java:2944)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.widget.AbsListView$FlingRunnable.run(AbsListView.java:2485)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.os.Handler.handleCallback(Handler.java:587)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.os.Handler.dispatchMessage(Handler.java:92)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.os.Looper.loop(Looper.java:123)
11-15 12:45:22.446: E/AndroidRuntime(276):  at android.app.ActivityThread.main(ActivityThread.java:4627)
11-15 12:45:22.446: E/AndroidRuntime(276):  at java.lang.reflect.Method.invokeNative(Native Method)
11-15 12:45:22.446: E/AndroidRuntime(276):  at java.lang.reflect.Method.invoke(Method.java:521)
11-15 12:45:22.446: E/AndroidRuntime(276):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
11-15 12:45:22.446: E/AndroidRuntime(276):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
11-15 12:45:22.446: E/AndroidRuntime(276):  at dalvik.system.NativeStart.main(Native Method)

Solution

Put NullPointer check on String.valueOf method

Like:-

package com.example.yao;

  import java.util.ArrayList;
  import java.util.List;

  import android.content.Context;
  import android.graphics.drawable.Drawable;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.ArrayAdapter;
  import android.widget.ImageView;
  import android.widget.TextView;

  public class zCustomUsersAdapter extends ArrayAdapter<YAOYVD> {

      public zCustomUsersAdapter(Context context, List<YAOYVD> users) {
          super(context, 0, users);

       }

       @Override
       public View getView(int position, View convertView, ViewGroup parent) {
          // Get the data item for this position
         // User user = getItem(position);
           YAOYVD user = getItem(position); 
          // Check if an existing view is being reused, otherwise inflate the view
          if (convertView == null) {
             convertView = LayoutInflater.from(getContext()).inflate(R.layout.zitem_user, parent, false);
          }
          // Lookup view for data population
          TextView tvName = (TextView) convertView.findViewById(R.id.tvName);
          TextView tvHome = (TextView) convertView.findViewById(R.id.tvHometown);

          ImageView tvImage = (ImageView) convertView.findViewById(R.id.ivUserIcon);
          // Populate the data into the template view using the data object
          tvName.setText(user.getID_YAO()!=null ? String.valueOf(user.getID_YAO()): null);
                //.name);
          tvHome.setText(user.getID_YAO() != null ? String.valueOf(user.getID_YAO()):         null);
          //.hometown);

          if(user.getSPIC_YAO() != null{
                 tvImage.setBackgroundResource(user.getSPIC_YAO()); 
          }

         return convertView;
     }
}

The problem can be either you string value are getting null or background resource id is wrong. It's better if you put proper check on values.

Answered By - VikasGoyal