自定義BaseAdapter空指針

我得到一個空ponter在lv1.setAdapter(myAdapter)，我不明白爲什麼。有人可以看到最新的錯誤？自定義BaseAdapter空指針

我想實現兩線列表

MyActivity.class

final ListView lv1 = (ListView) findViewById(R.id.ListView01); 
      Log.d("",topicTitle.toString() + "----------" + topicAuthor.toString()); //not null 
      MyCustomBaseAdapter myAdapter = new MyCustomBaseAdapter(DiscussionTopics.this, topicTitle , topicAuthor); 
      lv1.setAdapter(myAdapter);

MyCustomBaseAdapter.class

public class MyCustomBaseAdapter extends BaseAdapter { 
    private static ArrayList<String> topics; 
    private static ArrayList<String> author; 
    private LayoutInflater mInflater; 
    public MyCustomBaseAdapter(Context context, ArrayList<String> topics, ArrayList<String> author) { 
     this.topics = topics; 
     this.author = author; 
     mInflater = LayoutInflater.from(context); 
    } 
    public long getItemId(int position) { 
     return position; 
    } 
    public View getView(int position, View convertView, ViewGroup parent) { 
     ViewHolder holder; 
     if (convertView == null) { 
      convertView = mInflater.inflate(R.layout.custom_row_view, null); 
      holder = new ViewHolder(); 
      holder.title = (TextView) convertView.findViewById(R.id.title); 
      holder.author = (TextView) convertView.findViewById(R.id.author); 

      convertView.setTag(holder); 
     } else { 
      holder = (ViewHolder) convertView.getTag(); 
     } 
     holder.title.setText(topics.get(position)); 
     holder.author.setText(author.get(position)); 
     return convertView; 
    } 
    static class ViewHolder { 
     TextView title; 
     TextView author; 
    } 
    public int getCount() { 
     // TODO Auto-generated method stub 
     return topics.size(); 
    } 
    public Object getItem(int position) { 
     // TODO Auto-generated method stub 
     return topics.get(position); 
    } 
}

來源

2012-06-07 code511788465541441

你能幫助我們多一點，給行號，給予了NPE的佈局？ –

@FrankSposaro它出現在行'lv1.setAdapter（myAdapter）;' – code511788465541441

我猜'lv1'是'null'，因爲你沒有在活動上設置任何內容......我們已經看到了十幾篇文章，就像這在過去的日子裏 –

所以你從來沒有在R.id.ListView01得到一個處理程序

final ListView lv1 = (ListView) findViewById(R.id.ListView01);

確保這條線之前，你的電話的setContentView（），並給予它包含R.id.ListView01

來源

2012-06-07 20:01:20

自定義BaseAdapter空指針

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