凌空NullPointerException

Question

我使用的是volley.jar，在编译时没有错误，但是有运行时异常。

然后添加volley.jar和build path。什么是问题？

CustomAdapter.java

public class CustomAdapter extends BaseAdapter {

Context context;
List<Games> rowItems;

public CustomAdapter(Context context, List<Games> rowItems) {
    this.context = context;
    this.rowItems = rowItems;
}

@Override
public int getCount() {
    return rowItems.size();
}

@Override
public Object getItem(int position) {
    return rowItems.get(position);
}

@Override
public long getItemId(int position) {
    return rowItems.indexOf(getItem(position));
}

/* private view holder class */
private class ViewHolder {
    NetworkImageView profile_pic;
    TextView member_name;
    TextView status;
    TextView contactType;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    ViewHolder holder = null;

    LayoutInflater mInflater = (LayoutInflater) context
            .getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
    if (convertView == null) {
        convertView = mInflater.inflate(R.layout.list_item, null);
        holder = new ViewHolder();

        holder.member_name = (TextView) convertView
                .findViewById(R.id.member_name);
        holder.profile_pic = (NetworkImageView) convertView
                .findViewById(R.id.profile_pic);
        holder.status = (TextView) convertView.findViewById(R.id.status);
        holder.contactType = (TextView) convertView
                .findViewById(R.id.contact_type);

        Games row_pos = rowItems.get(position);

        ImageLoader il = VolleySingleton.getInstance().getImageLoader();

        holder.profile_pic.setImageUrl(IMAGE_URL ,il);


        holder.member_name.setText(row_pos.getChampionId());
        holder.status.setText(row_pos.getGameMode());
        holder.contactType.setText(row_pos.getStats().getItem0());
        Log.d("aaa", "position : " + position );
        Log.d("aaa", "row_pos.getChampionId()" + row_pos.getChampionId());
        Log.d("aaa", "row_pos.getGameMode()" + row_pos.getGameMode());
        Log.d("aaa", "row_pos.getStats().getItem0()" + row_pos.getStats().getItem0());

        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
        Games row_pos = rowItems.get(position);

        ImageLoader il = VolleySingleton.getInstance().getImageLoader();
        holder.profile_pic.setImageUrl(IMAGE_URL,il);

        holder.member_name.setText(row_pos.getChampionId());
        holder.status.setText(row_pos.getGameMode());
        holder.contactType.setText(row_pos.getStats().getItem0());
        Log.d("aaa", "position : " + position );
        Log.d("aaa", "row_pos.getChampionId()" + row_pos.getChampionId());
        Log.d("aaa", "row_pos.getGameMode()" + row_pos.getGameMode());
        Log.d("aaa", "row_pos.getStats().getItem0()" + row_pos.getStats().getItem0());

    }

    return convertView;
}

<com.android.volley.toolbox.NetworkImageView
    android:id="@+id/profile_pic"
    android:layout_width="70dp"
    android:layout_height="70dp"
    android:contentDescription="desc"
    android:paddingLeft="10dp"
    android:paddingRight="10dp" />

<TextView
    android:id="@+id/member_name"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="10dp"
    android:layout_toRightOf="@+id/profile_pic"
    android:paddingBottom="10dp"
    android:text="txt"
    android:textSize="20sp" />

<TextView
    android:id="@+id/status"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/member_name"
    android:layout_below="@+id/member_name"
    android:text="txt"
    android:textSize="16sp" />

<TextView
    android:id="@+id/contact_type"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/member_name"
    android:layout_alignBottom="@+id/member_name"
    android:layout_alignParentRight="true"
    android:text="txt" />

Answer 1

我解决了这些问题。在我的volleysingleton类getImageLoader方法中有一些错误，这段代码运行良好。