java - 带有ListAdapter的奇怪NullPointerException

好的，所以我创建了一个ListView和自己的ListAdapter，但是每当我将结果添加到ListAdapter时，它都会崩溃并显示NullPointerException

Adaptor打开时，我确实启动了filldata()

我的代码：

     public void filldata() throws IOException{
        MyAdapter adapter = new MyAdapter ();

        for (int i = 1; i <= 10; i++) {

            AdapterItem test = new AdapterItem(1+i, 2+i, 3+i);

            adapter.addAdapterItem(test);
        }

        setListAdapter(adapter);

    }
}

public class MyAdapter extends BaseAdapter {
    private List<AdapterItem> items;

    public void addAdapterItem(AdapterItem item) {
        items.add(item);
    }

    public int getCount() {
      return items.size();
    }

    public Object getItem(int position) {
      return items.get(position);
    }

    @Override
    public long getItemId(int position) {
            return position;
    }

    public View getView(int position, View convertView, ViewGroup parent){
      View rowView = getLayoutInflater().inflate(R.layout.searchitemview, parent);
      TextView firstTextView = (TextView) rowView.findViewById(R.id.txtTitle);
      firstTextView.setText(items.get(position).first);
      // do the same with second and third
      return rowView;
    }
}

class AdapterItem {
    public String first;
    public String second;
    public String third;

    public AdapterItem(String first, String second, String third) {
        this.first = first;
        this.second = second;
        this.third = third;
    }
}

到达MyAdapter adapter = new MyAdapter ();时崩溃

最佳答案

在这里换。

public class MyAdapter extends BaseAdapter
{
    private List<AdapterItem> items=new ArrayList<AdapterItem>();
}

您没有在item类中实例化MyAdapter。

关于java - 带有ListAdapter的奇怪NullPointerException，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/8636743/