onContextItemSelected - item id NullPointerException

Question

我有自定义适配器的ListView。直到现在我都有长按的上下文菜单。并通过此

重新执行此操作

 getListView().setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() 
    {

        public void onItemClick(AdapterView<?> parent, View v, int position, long id)
        {
            //To register the button with context menu.
                            registerForContextMenu(getListView());
                            openContextMenu(getListView());

        }
    });

仅限于此

registerForContextMenu(getListView());

在此更改之前它可以正常工作，但现在我在info.id处有NullPointerException，我不知道如何修复它。谢谢你的回复。

 @Override
public boolean onContextItemSelected(MenuItem item) {
    AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
    Intent i;
    Log.d("item id", String.valueOf(item.getItemId()));
    switch (item.getItemId()) {

    case R.id.spotreba:    
         i = new Intent(this, SpotrebaActivity.class);
         i.putExtra("idAuta", info.id);
         startActivityForResult(i, REQUEST_ADD_AUTO);
         return true;
         .
         .
         .

Answer 1

您应该在活动中使用ListView注册上下文菜单，而不是在您创建的内部类（onItemClickListener）中注册。

将其写为..

registerForContextMenu(getListView());
getListView().setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() 
    {

        public void onItemClick(AdapterView<?> parent, View v, int position, long id)
        {
               openContextMenu(getListView());
        }
    });