notifyDataSetChanged Android ListView [英] notifyDataSetChanged Android ListView

问题描述

我的应用程序类中有一个项目列表:

I have a list of items in my Application class:

public class MyApp extends Application {
   private static ArrayList<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();
   //GET AND SET
}

我想在 ListView 中使用它.我有一个按钮可以在 MyApp 列表中添加一个元素:

I would to use it in ListView. I have a button to add one element in MyApp list:

public void addBase(View view){
   MyApp.add2List(....); //add to MyApp.list
   adapter.notifyDataSetChanged();
}

在同一个活动中，我设置了 ListView:

And in the same activity I set ListView:

list=(ListView)findViewById(R.id.list_view);         
adapter=new MyListAdapter(this, R.layout.list_item, Session.getList());
list.setAdapter(adapter);

这是我的适配器:

public class MyListAdapter extends ArrayAdapter<HashMap<String, String>> {

  private Context _context;
  private Activity activity;
  private ArrayList<HashMap<String, String>> data;
  private static LayoutInflater inflater=null;

  public MyListAdapter(Context context, int resourceId, ArrayList<HashMap<String, String>> items) {
    super(context, resourceId, items);
    this.data = items;
    _context = context;
    activity = ((Activity)context);
    inflater = activity.getLayoutInflater();    
  }


   public View getView(final int position, View convertView, ViewGroup parent) {
      View vi=convertView;
      final ArrayList<HashMap<String, String>> list = Session.getList();
      if(convertView==null){
         vi = inflater.inflate(R.layout.list_item, null);

         ImageButton delete = (ImageButton)vi.findViewById(R.id.delete_item);
         delete.setOnClickListener(new Button.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        list.remove(position);
                        notifyDataSetChanged();
                    }
                });

      }
      return vi;
  }

我使用了 notifyDataSetChanged() 方法，但它不起作用！！列表视图没有更新.
如果再次尝试创建适配器，添加按钮将起作用.

I used notifyDataSetChanged() method, but it doesn't work !! No update to listview.
If try to create adapter again, the add button work.

adapter=new MyListAdapter(this, R.layout.list_item, Session.getList());
list.setAdapter(adapter);

如何为删除按钮执行此操作?
为什么notifyDataSetChanged() 方法不起作用?

How can i do this for delete button ?
Why notifyDataSetChanged() method doesn't work ?

推荐答案

我解决了每次重新创建适配器.
不是很好的解决方案，但这是我唯一找到的.

I solve it to recreate everytime the adapter.
Not good solution but it's the only I've found.

这篇关于notifyDataSetChanged Android ListView的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！